From d76ec1c6b158fbf9e000bfe94baf49874d7ebc77 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Thu, 30 Apr 2026 22:27:14 +0200
Subject: [PATCH 01/27] Fix: Horizontal coordinate orientation (use
 -parallactic_angle)

---
 python/PiFinder/calc_utils.py | 19 +++++++++++++++++++
 python/PiFinder/integrator.py | 11 ++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/python/PiFinder/calc_utils.py b/python/PiFinder/calc_utils.py
index 112271a3d..af4741436 100644
--- a/python/PiFinder/calc_utils.py
+++ b/python/PiFinder/calc_utils.py
@@ -388,6 +388,25 @@ def ra_to_ha(self, ra_deg, dt):
 
         return ha_hrs * 180 / 12  # Hour angle [deg]
 
+    def radec_to_pa(self, ra_deg, dec_deg, dt):
+        """
+        Returns the parallactic angle of an object at (ra, dec) as seen from an
+        observer at latitiude, lat and time, dt. See hadec_to_pa() for how
+        parallactic angle is defined.
+
+        INPUTS:
+        ra_deg: Right ascension [deg]
+        dec_deg: Declination [deg]
+        dt: Python datetime object (must be timezone-aware)
+
+        RETURNS:
+        pa_deg: Parallactic angle [deg]
+        """
+        ha_deg = self.ra_to_ha(ra_deg, dt)  # Note that HA is in deg
+        lat_deg = self._observer_geoid.latitude.degrees
+        pa_deg = hadec_to_pa(ha_deg, dec_deg, lat_deg)
+        return pa_deg  # Parallactic angle [deg]
+
     def radec_to_roll(self, ra_deg, dec_deg, dt):
         """
         Returns the roll (field rotation) of an object at (ra, dec) as
diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 2457f4872..eac6a1602 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -319,6 +319,7 @@ def get_roll_by_mount_type(
     if mount_type == "Alt/Az":
         # Altaz mounts: Display chart in horizontal coordinates
         if location and dt:
+            """
             # We have location and time/date (and assume that location has been set)
             # Roll at the target RA/Dec in the horizontal frame
             roll_deg = calc_utils.sf_utils.radec_to_roll(ra_deg, dec_deg, dt)
@@ -332,12 +333,16 @@ def get_roll_by_mount_type(
                 roll_deg - np.sign(ha_deg) * 180
             )  # In essence, gives: roll_deg = -pa_deg
             # End of HACK
+            """
+            # chart.py uses roll to rotate the chart around the target center
+            # by roll in anti-clockwise direction. Use -parallactic_angle
+            roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
         else:
             # No position or time/date available, so set roll to 0.0
-            roll_deg = 0.0
+            roll_deg = 0.0  # NCP up
     elif mount_type == "EQ":
         # EQ-mounts: Display chart with NCP up so roll = 0.0
-        roll_deg = 0.0
+        roll_deg = 0.0  # NCP up
     else:
         logger.error(f"Unknown mount type: {mount_type}. Cannot set roll.")
         roll_deg = 0.0
@@ -347,6 +352,6 @@ def get_roll_by_mount_type(
     # EQ mounts: NCP up in northern hemisphere, SCP up in southern hemisphere
     if location:
         if location.lat < 0.0:
-            roll_deg += 180.0  # Southern hemisphere
+            roll_deg += 180.0  # Southern hemisphere TODO: Verify this
 
     return roll_deg

From 848ef57e61cb3858608b68eed681a20863fdadad Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Fri, 1 May 2026 22:56:22 +0100
Subject: [PATCH 02/27] Remove duplicate definition of dt

---
 python/PiFinder/integrator.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index eac6a1602..18e6bbf99 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -161,7 +161,6 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
 
                 # Set Alt/Az because it's needed for the catalogs for the
                 # Alt/Az mount type. TODO: Can this be moved to the catalog?
-                dt = shared_state.datetime()
                 if location and dt:
                     solved["Alt"], solved["Az"] = calc_utils.sf_utils.radec_to_altaz(
                         solved["RA"], solved["Dec"], dt

From 29cd601224077aa2d2d353a1fb2e920dd8f34fa0 Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Fri, 1 May 2026 23:45:41 +0100
Subject: [PATCH 03/27] Encapsulate functionality to set Alt, Az, Roll  in
 solved dict to a func

---
 python/PiFinder/integrator.py | 66 ++++++++++++++++++++---------------
 1 file changed, 38 insertions(+), 28 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 18e6bbf99..264692005 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -75,6 +75,7 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                 pass
 
             if type(next_image_solve) is dict:
+                # TODO: Refactor this bit:
                 # For camera solves, always start from last successful camera solve
                 # NOT from shared_state (which may contain IMU drift)
                 # This prevents IMU noise accumulation during failed solves
@@ -114,6 +115,7 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                     # We have a new image solve: Use plate-solving for RA/Dec
                     update_plate_solve_and_imu(imu_dead_reckoning, solved)
                 else:
+                    # TODO: In this case, it should run update_imu()
                     # Failed solve - clear constellation
                     solved["solve_source"] = "CAM_FAILED"
                     solved["constellation"] = ""
@@ -130,9 +132,9 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                 if imu:
                     update_imu(imu_dead_reckoning, solved, last_image_solve, imu)
 
-            # Push IMU updates only if newer than last push
+            # Update Alt, Az, Roll only if newer than last push
             if (
-                solved["RA"] and solved["solve_time"] > last_solve_time
+                solved["RA"] is not None and solved["solve_time"] > last_solve_time
                 # and solved["solve_source"] == "IMU"
             ):
                 last_solve_time = time.time()  # TODO: solve_time is ambiguous because it's also used for IMU dead-reckoning
@@ -141,31 +143,10 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                 # TODO: Is it necessary to set location?
                 # TODO: Altaz doesn't seem to be required for catalogs when in
                 #  EQ mode? Could be disabled in future when in EQ mode?
-                location = shared_state.location()
-                dt = shared_state.datetime()
-                if location:
-                    calc_utils.sf_utils.set_location(
-                        location.lat, location.lon, location.altitude
-                    )
-
-                # Set the roll so that the chart is displayed appropriately for the mount type
-                solved["Roll"] = get_roll_by_mount_type(
-                    solved["RA"], solved["Dec"], location, dt, mount_type
-                )
-
-                # Update remaining solved keys
-                # Calculate constellation for current position
-                solved["constellation"] = calc_utils.sf_utils.radec_to_constellation(
-                    solved["RA"], solved["Dec"]
-                )  # TODO: Can the outer brackets be omitted?
-
-                # Set Alt/Az because it's needed for the catalogs for the
-                # Alt/Az mount type. TODO: Can this be moved to the catalog?
-                if location and dt:
-                    solved["Alt"], solved["Az"] = calc_utils.sf_utils.radec_to_altaz(
-                        solved["RA"], solved["Dec"], dt
-                    )
-
+                update_solved_coords(solved, 
+                                     location=shared_state.location(), 
+                                     dt=shared_state.datetime(),
+                                     mount_type=mount_type)
                 # Push IMU update
                 shared_state.set_solution(solved)
                 shared_state.set_solve_state(True)
@@ -176,7 +157,6 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
 
 # ======== Wrapper and helper functions ===============================
 
-
 def update_plate_solve_and_imu(imu_dead_reckoning: ImuDeadReckoning, solved: dict):
     """
     Wrapper for ImuDeadReckoning.update_plate_solve_and_imu() to
@@ -274,6 +254,36 @@ def update_imu(
         )
 
 
+def update_solved_coords(solved, location, dt, mount_type):
+    """
+    Based on RA/Dec, update the following in dictionary 'solved':
+    solved["Alt"], solved["Az"], solved["Roll"], solved["constellation"]
+    """
+    if solved["RA"] is None or solved["Dec"] is None:
+        solved["constellation"] = None
+        solved["Alt"], solved["Az"] = None, None
+        solved["Roll"] = None
+        return
+
+    # Calculate constellation for current position
+    solved["constellation"] = calc_utils.sf_utils.radec_to_constellation(
+        solved["RA"], solved["Dec"]
+    )
+
+    if location and dt:
+        # Location needs to be set for Alt/Az and roll calculations
+        calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
+        # Set Alt/Az
+        solved["Alt"], solved["Az"] = calc_utils.sf_utils.radec_to_altaz(
+            solved["RA"], solved["Dec"], dt)
+        # Set the roll so that the chart is displayed appropriately for the mount type
+        solved["Roll"] = get_roll_by_mount_type(
+            solved["RA"], solved["Dec"], location, dt, mount_type)
+    else:
+        solved["Alt"], solved["Az"] = None, None
+        solved["Roll"] = None
+
+
 def set_cam2scope_alignment(imu_dead_reckoning: ImuDeadReckoning, solved: dict):
     """
     Set alignment.

From f53401a19de923be7f865d476a2f9d41f5e2205a Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 2 May 2026 00:35:00 +0100
Subject: [PATCH 04/27] 1) Ensure that AltAz is calculated when plate solved.
 2) Fall back to IMU dead-reckoning if plate-solve fails.

---
 python/PiFinder/integrator.py | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 264692005..5c3dfd1ad 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -62,9 +62,10 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
         # This holds the last image solve position info
         # so we can delta for IMU updates
         last_image_solve = None
-        last_solve_time = time.time()
+        #last_solve_time = time.time()
 
         while True:
+            pointing_updated = False  # Flag to track if pointing was updated in this loop
             state_utils.sleep_for_framerate(shared_state)
 
             # Check for new camera solve in queue
@@ -101,19 +102,15 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                 # For failed solves, preserve ALL position data from previous solve
                 # Don't recalculate from GPS (causes drift from GPS noise)
 
-                # Set solve_source and push camera solves immediately
                 if solved["RA"] is not None:
+                    # Successfully plate-solved:
                     last_image_solve = copy.deepcopy(solved)
                     solved["solve_source"] = "CAM"
-                    # Calculate constellation for successful solve
-                    solved["constellation"] = (
-                        calc_utils.sf_utils.radec_to_constellation(
-                            solved["RA"], solved["Dec"]
-                        )
-                    )
                     shared_state.set_solve_state(True)
                     # We have a new image solve: Use plate-solving for RA/Dec
                     update_plate_solve_and_imu(imu_dead_reckoning, solved)
+                    #last_solve_time = solved["solve_time"]
+                    pointing_updated = True
                 else:
                     # TODO: In this case, it should run update_imu()
                     # Failed solve - clear constellation
@@ -125,20 +122,18 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                     shared_state.set_solution(solved)
                     shared_state.set_solve_state(False)
 
-            elif imu_dead_reckoning.tracking:
+            if imu_dead_reckoning.tracking and not pointing_updated:
                 # Previous plate-solve exists so use IMU dead-reckoning from
                 # the last plate solved coordinates.
                 imu = shared_state.imu()
                 if imu:
+                    #last_solve_time = time.time()
                     update_imu(imu_dead_reckoning, solved, last_image_solve, imu)
+                    pointing_updated = True
 
             # Update Alt, Az, Roll only if newer than last push
-            if (
-                solved["RA"] is not None and solved["solve_time"] > last_solve_time
-                # and solved["solve_source"] == "IMU"
-            ):
-                last_solve_time = time.time()  # TODO: solve_time is ambiguous because it's also used for IMU dead-reckoning
-
+            if pointing_updated:
+                #last_solve_time = time.time()
                 # Set location for roll and altaz calculations.
                 # TODO: Is it necessary to set location?
                 # TODO: Altaz doesn't seem to be required for catalogs when in

From b898825f5db6cf2d11f91757f11bc6df0addb496 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 12:00:44 +0200
Subject: [PATCH 05/27] Fix: No need to add 180 deg to -parallactic_angle for
 horizontal coordinate chart display in the Southern hemisphere

---
 python/PiFinder/integrator.py | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 5c3dfd1ad..a08299b25 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -342,20 +342,17 @@ def get_roll_by_mount_type(
             # by roll in anti-clockwise direction. Use -parallactic_angle
             roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
         else:
-            # No position or time/date available, so set roll to 0.0
+            # No position or time/date available. Default to display in equatorial coordinate
             roll_deg = 0.0  # NCP up
     elif mount_type == "EQ":
-        # EQ-mounts: Display chart with NCP up so roll = 0.0
+        # EQ-mounts: Display chart in equatorial coordinates
         roll_deg = 0.0  # NCP up
+        # If location is available, adjust roll for hemisphere:
+        if location:
+            if location.lat < 0.0:
+                roll_deg = 180.0  # SCP up (for southern hemisphere)
     else:
         logger.error(f"Unknown mount type: {mount_type}. Cannot set roll.")
-        roll_deg = 0.0
-
-    # If location is available, adjust roll for hemisphere:
-    # Altaz: North up in northern hemisphere, South up in southern hemisphere
-    # EQ mounts: NCP up in northern hemisphere, SCP up in southern hemisphere
-    if location:
-        if location.lat < 0.0:
-            roll_deg += 180.0  # Southern hemisphere TODO: Verify this
+        roll_deg = 0.0  # NCP up
 
     return roll_deg

From ba6668598f68344c4c95ed5a7803e07a3441e1a3 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 12:18:45 +0200
Subject: [PATCH 06/27] Add "Coordinate Sys." to settings/Chart. (TODO need to
 update other languages)

---
 python/PiFinder/ui/menu_structure.py | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/python/PiFinder/ui/menu_structure.py b/python/PiFinder/ui/menu_structure.py
index 52c3bad7a..385c79a58 100644
--- a/python/PiFinder/ui/menu_structure.py
+++ b/python/PiFinder/ui/menu_structure.py
@@ -863,6 +863,30 @@ def _(key: str) -> Any:
                                 },
                             ],
                         },
+                        {
+                            "name": _("Coordinate Sys."),
+                            "class": UITextMenu,
+                            "select": "single",
+                            "config_option": "chart_coord",
+                            "items": [
+                                {
+                                    "name": _("Horizontal"),
+                                    "value": "horiz",
+                                },
+                                {
+                                    "name": _("EQ (auto)"),
+                                    "value": "eq_auto",
+                                },
+                                {
+                                    "name": _("EQ (NCP up)"),
+                                    "value": "eq_ncp",
+                                },
+                                {
+                                    "name": _("EQ (SCP up)"),
+                                    "value": "eq_scp",
+                                },
+                            ],
+                        },
                     ],
                 },
                 {

From ef04677b84bacb20d515b8463c57401c16429201 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 12:27:20 +0200
Subject: [PATCH 07/27] Rename settings

---
 python/PiFinder/ui/menu_structure.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/python/PiFinder/ui/menu_structure.py b/python/PiFinder/ui/menu_structure.py
index 385c79a58..ece253114 100644
--- a/python/PiFinder/ui/menu_structure.py
+++ b/python/PiFinder/ui/menu_structure.py
@@ -874,15 +874,15 @@ def _(key: str) -> Any:
                                     "value": "horiz",
                                 },
                                 {
-                                    "name": _("EQ (auto)"),
+                                    "name": _("EQ (Auto)"),
                                     "value": "eq_auto",
                                 },
                                 {
-                                    "name": _("EQ (NCP up)"),
+                                    "name": _("EQ (North-up)"),
                                     "value": "eq_ncp",
                                 },
                                 {
-                                    "name": _("EQ (SCP up)"),
+                                    "name": _("EQ (South-up)"),
                                     "value": "eq_scp",
                                 },
                             ],

From 265a2a321e22a8b6c42fc14d7c33cf913285a8d8 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 12:31:01 +0200
Subject: [PATCH 08/27] Add default config

---
 default_config.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/default_config.json b/default_config.json
index 7ce509784..585e6d4ad 100644
--- a/default_config.json
+++ b/default_config.json
@@ -16,6 +16,7 @@
     "chart_dso": 128,
     "chart_reticle": 128,
     "chart_constellations": 64,
+    "chart_coord": "horiz",
     "solve_pixel": [256, 256],
     "gps_type": "ublox",
     "gps_baud_rate": 9600,

From b918b4d417b767bb05ffb4fb5dd48633cdd9125e Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 16:53:12 +0200
Subject: [PATCH 09/27] Rename --> chart_coord_sys

---
 default_config.json                  | 2 +-
 python/PiFinder/ui/menu_structure.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/default_config.json b/default_config.json
index 585e6d4ad..e16948919 100644
--- a/default_config.json
+++ b/default_config.json
@@ -16,7 +16,7 @@
     "chart_dso": 128,
     "chart_reticle": 128,
     "chart_constellations": 64,
-    "chart_coord": "horiz",
+    "chart_coord_sys": "horiz",
     "solve_pixel": [256, 256],
     "gps_type": "ublox",
     "gps_baud_rate": 9600,
diff --git a/python/PiFinder/ui/menu_structure.py b/python/PiFinder/ui/menu_structure.py
index ece253114..5d8790119 100644
--- a/python/PiFinder/ui/menu_structure.py
+++ b/python/PiFinder/ui/menu_structure.py
@@ -867,7 +867,7 @@ def _(key: str) -> Any:
                             "name": _("Coordinate Sys."),
                             "class": UITextMenu,
                             "select": "single",
-                            "config_option": "chart_coord",
+                            "config_option": "chart_coord_sys",
                             "items": [
                                 {
                                     "name": _("Horizontal"),

From ae5cb306d2b13c38dbc9f661ec65b55de9a97c1c Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 17:11:23 +0200
Subject: [PATCH 10/27] Use chart_coord_sys configuration to determine roll

---
 python/PiFinder/integrator.py | 71 ++++++++++++++---------------------
 1 file changed, 29 insertions(+), 42 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index a08299b25..d5a0e35f8 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -52,9 +52,6 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
         solved = get_initialized_solved_dict()
         cfg = config.Config()
 
-        mount_type = cfg.get_option("mount_type")
-        logger.debug(f"mount_type = {mount_type}")
-
         # Set up dead-reckoning tracking by the IMU:
         imu_dead_reckoning = ImuDeadReckoning(cfg.get_option("screen_direction"))
         # imu_dead_reckoning.set_cam2scope_alignment(q_scope2cam)  # TODO: Enable when q_scope2cam is available from alignment
@@ -138,10 +135,10 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                 # TODO: Is it necessary to set location?
                 # TODO: Altaz doesn't seem to be required for catalogs when in
                 #  EQ mode? Could be disabled in future when in EQ mode?
-                update_solved_coords(solved, 
+                convert_solved_coords(solved, 
                                      location=shared_state.location(), 
                                      dt=shared_state.datetime(),
-                                     mount_type=mount_type)
+                                     chart_coord_sys=cfg.get_option("chart_coord_sys"))
                 # Push IMU update
                 shared_state.set_solution(solved)
                 shared_state.set_solve_state(True)
@@ -249,9 +246,9 @@ def update_imu(
         )
 
 
-def update_solved_coords(solved, location, dt, mount_type):
+def convert_solved_coords(solved, location, dt, chart_coord_sys):
     """
-    Based on RA/Dec, update the following in dictionary 'solved':
+    Convert RA/Dec coordinate to the following in the dictionary 'solved':
     solved["Alt"], solved["Az"], solved["Roll"], solved["constellation"]
     """
     if solved["RA"] is None or solved["Dec"] is None:
@@ -271,9 +268,9 @@ def update_solved_coords(solved, location, dt, mount_type):
         # Set Alt/Az
         solved["Alt"], solved["Az"] = calc_utils.sf_utils.radec_to_altaz(
             solved["RA"], solved["Dec"], dt)
-        # Set the roll so that the chart is displayed appropriately for the mount type
-        solved["Roll"] = get_roll_by_mount_type(
-            solved["RA"], solved["Dec"], location, dt, mount_type)
+        # Set the roll for the chart depending on the configuration
+        solved["Roll"] = get_roll_by_chart_coord_sys(
+            solved["RA"], solved["Dec"], chart_coord_sys, location=location, dt=dt)
     else:
         solved["Alt"], solved["Az"] = None, None
         solved["Roll"] = None
@@ -301,58 +298,48 @@ def set_cam2scope_alignment(imu_dead_reckoning: ImuDeadReckoning, solved: dict):
     imu_dead_reckoning.set_cam2scope_alignment(solved_cam, solved_scope)
 
 
-def get_roll_by_mount_type(
+def get_roll_by_chart_coord_sys(
     ra_deg: float,  # Right Ascension of the target in degrees
     dec_deg: float,  # Declination of the target in degrees
-    location,  # astropy EarthLocation object or None
-    dt: datetime.datetime,  # datetime.datetime object or None
-    mount_type: str,  # "Alt/Az" or "EQ"
+    chart_coord_sys: str,  # "Alt/Az" or "EQ"
+    location=None,  # astropy EarthLocation object or None
+    dt: datetime.datetime | None = None,  # datetime.datetime object or None
 ) -> float:
     """
-    Returns the roll (in degrees) depending on the mount type so that the chart
-    is displayed appropriately for the mount type. The RA and Dec of the target
-    should be provided (in degrees).
+    Returns the roll (in degrees) depending on the configured chart coordinate
+    system. The RA and Dec of the target should be provided (in degrees).
 
-    * Alt/Az mount: Display the chart in the horizontal coordinate so that up
-      in the chart points to the Zenith.
-    * EQ mount: Display the chart in the equatorial coordinate system with the
-      NCP up so roll = 0.
+    * horiz: Display the chart in the horizontal coordinate so that up in the
+      chart points to the Zenith.
+    * EQ (Auto): Display the chart in the equatorial coordinate system.
+      Automatically select NCP or SCP-up based on location.
+    * EQ (North-up), EQ (South-up): Display chart in the equatorial coordinate
+      system with NCP or SCP up.
 
     Assumes that location has already been set in calc_utils.sf_utils.
     """
-    if mount_type == "Alt/Az":
-        # Altaz mounts: Display chart in horizontal coordinates
+    if chart_coord_sys == "horiz":
+        # Horizontal coordinates (alt/az):
         if location and dt:
-            """
-            # We have location and time/date (and assume that location has been set)
-            # Roll at the target RA/Dec in the horizontal frame
-            roll_deg = calc_utils.sf_utils.radec_to_roll(ra_deg, dec_deg, dt)
-
-            # HACK:
-            # The IMU direction flips at a certaint point. Could due to a
-            # an issue in the formula in calc_utils.sf_utils.hadec_to_roll()
-            # This is a temperary hack for testing.
-            ha_deg = calc_utils.sf_utils.ra_to_ha(ra_deg, dt)
-            roll_deg = (
-                roll_deg - np.sign(ha_deg) * 180
-            )  # In essence, gives: roll_deg = -pa_deg
-            # End of HACK
-            """
             # chart.py uses roll to rotate the chart around the target center
             # by roll in anti-clockwise direction. Use -parallactic_angle
             roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
         else:
             # No position or time/date available. Default to display in equatorial coordinate
             roll_deg = 0.0  # NCP up
-    elif mount_type == "EQ":
-        # EQ-mounts: Display chart in equatorial coordinates
-        roll_deg = 0.0  # NCP up
+    elif chart_coord_sys == "EQ (Auto)":
+        # Equatorial coordinates: (North-up/south-up depending on latitude)
+        roll_deg = 0.0  # Default (NCP up)
         # If location is available, adjust roll for hemisphere:
         if location:
             if location.lat < 0.0:
                 roll_deg = 180.0  # SCP up (for southern hemisphere)
+    elif chart_coord_sys == "EQ (North-up)":
+        roll_deg = 0.0
+    elif chart_coord_sys == "EQ (South-up)":
+        roll_deg = 180.0
     else:
-        logger.error(f"Unknown mount type: {mount_type}. Cannot set roll.")
+        logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
         roll_deg = 0.0  # NCP up
 
     return roll_deg

From 1a8c4b166fc7c4da66b6d21cebb1f72cdfe6fdd7 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 17:55:33 +0200
Subject: [PATCH 11/27] Rationalize solve_time. Record solve_time and push
 updates when solve_time > last_solve_time. Remove commented out solve_time.

---
 python/PiFinder/integrator.py | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index d5a0e35f8..fb6dd9203 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -59,7 +59,7 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
         # This holds the last image solve position info
         # so we can delta for IMU updates
         last_image_solve = None
-        #last_solve_time = time.time()
+        last_solve_time = time.time()
 
         while True:
             pointing_updated = False  # Flag to track if pointing was updated in this loop
@@ -106,14 +106,11 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                     shared_state.set_solve_state(True)
                     # We have a new image solve: Use plate-solving for RA/Dec
                     update_plate_solve_and_imu(imu_dead_reckoning, solved)
-                    #last_solve_time = solved["solve_time"]
                     pointing_updated = True
                 else:
-                    # TODO: In this case, it should run update_imu()
                     # Failed solve - clear constellation
                     solved["solve_source"] = "CAM_FAILED"
-                    solved["constellation"] = ""
-
+                    solved["constellation"] = ""  # NOTE: This gets over-written by IMU dead-reckoning
                     # Push failed solved immediately
                     # This ensures auto-exposure sees Matches=0 for failed solves
                     shared_state.set_solution(solved)
@@ -124,13 +121,11 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                 # the last plate solved coordinates.
                 imu = shared_state.imu()
                 if imu:
-                    #last_solve_time = time.time()
                     update_imu(imu_dead_reckoning, solved, last_image_solve, imu)
                     pointing_updated = True
 
             # Update Alt, Az, Roll only if newer than last push
-            if pointing_updated:
-                #last_solve_time = time.time()
+            if pointing_updated and solved["solve_time"] > last_solve_time:
                 # Set location for roll and altaz calculations.
                 # TODO: Is it necessary to set location?
                 # TODO: Altaz doesn't seem to be required for catalogs when in
@@ -139,6 +134,8 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                                      location=shared_state.location(), 
                                      dt=shared_state.datetime(),
                                      chart_coord_sys=cfg.get_option("chart_coord_sys"))
+                last_solve_time = solved["solved_time"]
+                
                 # Push IMU update
                 shared_state.set_solution(solved)
                 shared_state.set_solve_state(True)
@@ -196,6 +193,7 @@ def update_imu(
         imu["quat"], quaternion.quaternion
     ), "Expecting quaternion.quaternion type"  # TODO: Can be removed later
     q_x2imu = imu["quat"]  # Current IMU measurement (quaternion)
+    imu_time = time.time()
 
     # When moving, switch to tracking using the IMU
     angle_moved = qt.get_quat_angular_diff(last_image_solve["imu_quat"], q_x2imu)
@@ -227,8 +225,7 @@ def update_imu(
         # Store the current scope pointing estimate
         scope_eq = imu_dead_reckoning.get_scope_radec()
         solved["RA"], solved["Dec"], solved["Roll"] = scope_eq.get_deg(use_none=True)
-
-        solved["solve_time"] = time.time()
+        solved["solve_time"] = imu_time
         solved["solve_source"] = "IMU"
 
         # Logging for states updated in solved:
@@ -250,6 +247,8 @@ def convert_solved_coords(solved, location, dt, chart_coord_sys):
     """
     Convert RA/Dec coordinate to the following in the dictionary 'solved':
     solved["Alt"], solved["Az"], solved["Roll"], solved["constellation"]
+
+    TODO: This functionality should be moved to chart.py
     """
     if solved["RA"] is None or solved["Dec"] is None:
         solved["constellation"] = None

From 27033ab11380d3bd7198241c0a9f5e60bbbcbf0b Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 22:08:47 +0200
Subject: [PATCH 12/27] Re-order functions

---
 python/PiFinder/integrator.py | 46 ++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index fb6dd9203..7257e5700 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -275,28 +275,6 @@ def convert_solved_coords(solved, location, dt, chart_coord_sys):
         solved["Roll"] = None
 
 
-def set_cam2scope_alignment(imu_dead_reckoning: ImuDeadReckoning, solved: dict):
-    """
-    Set alignment.
-    TODO: Do this once at alignment
-    """
-    # RA, Dec of camera center::
-    solved_cam = RaDecRoll()
-    solved_cam.set_from_deg(
-        solved["camera_center"]["RA"],
-        solved["camera_center"]["Dec"],
-        solved["camera_center"]["Roll"],
-    )
-
-    # RA, Dec of target (where scope is pointing):
-    solved["Roll"] = 0  # Target roll isn't calculated by Tetra3. Set to zero here
-    solved_scope = RaDecRoll()
-    solved_scope.set_from_deg(solved["RA"], solved["Dec"], solved["Roll"])
-
-    # Set alignment in imu_dead_reckoning
-    imu_dead_reckoning.set_cam2scope_alignment(solved_cam, solved_scope)
-
-
 def get_roll_by_chart_coord_sys(
     ra_deg: float,  # Right Ascension of the target in degrees
     dec_deg: float,  # Declination of the target in degrees
@@ -316,6 +294,8 @@ def get_roll_by_chart_coord_sys(
       system with NCP or SCP up.
 
     Assumes that location has already been set in calc_utils.sf_utils.
+
+    # TODO: Move this to chart.py
     """
     if chart_coord_sys == "horiz":
         # Horizontal coordinates (alt/az):
@@ -342,3 +322,25 @@ def get_roll_by_chart_coord_sys(
         roll_deg = 0.0  # NCP up
 
     return roll_deg
+
+
+def set_cam2scope_alignment(imu_dead_reckoning: ImuDeadReckoning, solved: dict):
+    """
+    Set alignment.
+    TODO: Do this once at alignment
+    """
+    # RA, Dec of camera center::
+    solved_cam = RaDecRoll()
+    solved_cam.set_from_deg(
+        solved["camera_center"]["RA"],
+        solved["camera_center"]["Dec"],
+        solved["camera_center"]["Roll"],
+    )
+
+    # RA, Dec of target (where scope is pointing):
+    solved["Roll"] = 0  # Target roll isn't calculated by Tetra3. Set to zero here
+    solved_scope = RaDecRoll()
+    solved_scope.set_from_deg(solved["RA"], solved["Dec"], solved["Roll"])
+
+    # Set alignment in imu_dead_reckoning
+    imu_dead_reckoning.set_cam2scope_alignment(solved_cam, solved_scope)

From 507c2bcc0412d68903d66226402a58b1441ee5f6 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 2 May 2026 23:03:31 +0200
Subject: [PATCH 13/27] Refactor: Explicitly return values rather than changing
 the solved dictionary in place

---
 python/PiFinder/integrator.py | 78 +++++++++++++++++------------------
 1 file changed, 38 insertions(+), 40 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 7257e5700..c7d2d5fca 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -126,19 +126,24 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
 
             # Update Alt, Az, Roll only if newer than last push
             if pointing_updated and solved["solve_time"] > last_solve_time:
-                # Set location for roll and altaz calculations.
-                # TODO: Is it necessary to set location?
-                # TODO: Altaz doesn't seem to be required for catalogs when in
-                #  EQ mode? Could be disabled in future when in EQ mode?
-                convert_solved_coords(solved, 
-                                     location=shared_state.location(), 
-                                     dt=shared_state.datetime(),
-                                     chart_coord_sys=cfg.get_option("chart_coord_sys"))
-                last_solve_time = solved["solved_time"]
+                solved["constellation"] = get_constellation(solved["RA"], solved["Dec"])
+
+                # TODO: Altaz doesn't seem to be required for catalogs when in 
+                # EQ mode? Could be disabled in future when in EQ mode?
+                solved["Alt"], solved["Az"] = get_alt_az(solved["RA"], solved["Dec"], 
+                                                        shared_state.location(), 
+                                                        shared_state.datetime())
+
+                solved["Roll"] = get_roll_by_chart_coord_sys(solved["RA"], solved["Dec"], 
+                                                                chart_coord_sys=cfg.get_option("chart_coord_sys"),
+                                                                location=shared_state.location(), 
+                                                                dt=shared_state.datetime())
                 
-                # Push IMU update
-                shared_state.set_solution(solved)
-                shared_state.set_solve_state(True)
+                if (solved["RA"] is not None) and (solved["Dec"] is not None):
+                    # Push new solved to shared state
+                    shared_state.set_solution(solved)
+                    shared_state.set_solve_state(True)
+                    last_solve_time = solved["solved_time"]
 
     except EOFError:
         logger.error("Main no longer running for integrator")
@@ -243,36 +248,26 @@ def update_imu(
         )
 
 
-def convert_solved_coords(solved, location, dt, chart_coord_sys):
+def get_constellation(RA_deg, Dec_deg) -> str:
     """
-    Convert RA/Dec coordinate to the following in the dictionary 'solved':
-    solved["Alt"], solved["Az"], solved["Roll"], solved["constellation"]
-
-    TODO: This functionality should be moved to chart.py
+    Get constellation name from the current RA/Dec position.
     """
-    if solved["RA"] is None or solved["Dec"] is None:
-        solved["constellation"] = None
-        solved["Alt"], solved["Az"] = None, None
-        solved["Roll"] = None
-        return
-
-    # Calculate constellation for current position
-    solved["constellation"] = calc_utils.sf_utils.radec_to_constellation(
-        solved["RA"], solved["Dec"]
-    )
+    if RA_deg is None or Dec_deg is None:
+        return ""
+    else:
+        return calc_utils.sf_utils.radec_to_constellation(RA_deg, Dec_deg)
 
-    if location and dt:
-        # Location needs to be set for Alt/Az and roll calculations
-        calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
-        # Set Alt/Az
-        solved["Alt"], solved["Az"] = calc_utils.sf_utils.radec_to_altaz(
-            solved["RA"], solved["Dec"], dt)
-        # Set the roll for the chart depending on the configuration
-        solved["Roll"] = get_roll_by_chart_coord_sys(
-            solved["RA"], solved["Dec"], chart_coord_sys, location=location, dt=dt)
+
+def get_alt_az(RA_deg, Dec_deg, location, dt) -> tuple[float | None, float | None]:
+    """
+    Get Alt/Az from RA/Dec, location and datetime.
+    RETURNS: alt_deg, az_deg
+    """
+    if RA_deg is None or Dec_deg is None:
+        return None, None
     else:
-        solved["Alt"], solved["Az"] = None, None
-        solved["Roll"] = None
+        calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
+        return calc_utils.sf_utils.radec_to_altaz(RA_deg, Dec_deg, dt)
 
 
 def get_roll_by_chart_coord_sys(
@@ -280,7 +275,7 @@ def get_roll_by_chart_coord_sys(
     dec_deg: float,  # Declination of the target in degrees
     chart_coord_sys: str,  # "Alt/Az" or "EQ"
     location=None,  # astropy EarthLocation object or None
-    dt: datetime.datetime | None = None,  # datetime.datetime object or None
+    dt: datetime.datetime | None=None,  # datetime.datetime object or None
 ) -> float:
     """
     Returns the roll (in degrees) depending on the configured chart coordinate
@@ -294,12 +289,15 @@ def get_roll_by_chart_coord_sys(
       system with NCP or SCP up.
 
     Assumes that location has already been set in calc_utils.sf_utils.
-
     # TODO: Move this to chart.py
     """
+    if (ra_deg is None) or (dec_deg is None):
+        return None  # Can't calculate roll without RA/Dec
+
     if chart_coord_sys == "horiz":
         # Horizontal coordinates (alt/az):
         if location and dt:
+            calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
             # chart.py uses roll to rotate the chart around the target center
             # by roll in anti-clockwise direction. Use -parallactic_angle
             roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)

From 7c53700d82f9aefbbcba788dd02f8d5d6e312a9c Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sun, 3 May 2026 13:10:07 +0100
Subject: [PATCH 14/27] import __future__ to support | for type hints

---
 python/PiFinder/integrator.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index c7d2d5fca..1f8432933 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -13,6 +13,7 @@
 - Refactor into class PointingTracker
 
 """
+from __future__ import annotations  # To support | in typehints (remove this for Python 3.10+)
 
 import datetime
 import queue
@@ -275,7 +276,7 @@ def get_roll_by_chart_coord_sys(
     dec_deg: float,  # Declination of the target in degrees
     chart_coord_sys: str,  # "Alt/Az" or "EQ"
     location=None,  # astropy EarthLocation object or None
-    dt: datetime.datetime | None=None,  # datetime.datetime object or None
+    dt: datetime.datetime | None = None,  # datetime object or None
 ) -> float:
     """
     Returns the roll (in degrees) depending on the configured chart coordinate

From 6a0c89228e5d0c31b31329bbdd810e5de33c3d5e Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Thu, 7 May 2026 19:28:11 +0100
Subject: [PATCH 15/27] Fix incorrect setting value. Also rename settings for
 clarity

---
 python/PiFinder/integrator.py        | 7 ++++---
 python/PiFinder/ui/menu_structure.py | 4 ++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 1f8432933..ab110cf15 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -144,6 +144,7 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                     # Push new solved to shared state
                     shared_state.set_solution(solved)
                     shared_state.set_solve_state(True)
+                    print(solved)
                     last_solve_time = solved["solved_time"]
 
     except EOFError:
@@ -305,16 +306,16 @@ def get_roll_by_chart_coord_sys(
         else:
             # No position or time/date available. Default to display in equatorial coordinate
             roll_deg = 0.0  # NCP up
-    elif chart_coord_sys == "EQ (Auto)":
+    elif chart_coord_sys == "eq_auto":
         # Equatorial coordinates: (North-up/south-up depending on latitude)
         roll_deg = 0.0  # Default (NCP up)
         # If location is available, adjust roll for hemisphere:
         if location:
             if location.lat < 0.0:
                 roll_deg = 180.0  # SCP up (for southern hemisphere)
-    elif chart_coord_sys == "EQ (North-up)":
+    elif chart_coord_sys == "eq_north_up":
         roll_deg = 0.0
-    elif chart_coord_sys == "EQ (South-up)":
+    elif chart_coord_sys == "eq_south_up":
         roll_deg = 180.0
     else:
         logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
diff --git a/python/PiFinder/ui/menu_structure.py b/python/PiFinder/ui/menu_structure.py
index 5d8790119..c6e69a90a 100644
--- a/python/PiFinder/ui/menu_structure.py
+++ b/python/PiFinder/ui/menu_structure.py
@@ -879,11 +879,11 @@ def _(key: str) -> Any:
                                 },
                                 {
                                     "name": _("EQ (North-up)"),
-                                    "value": "eq_ncp",
+                                    "value": "eq_north_up",
                                 },
                                 {
                                     "name": _("EQ (South-up)"),
-                                    "value": "eq_scp",
+                                    "value": "eq_south_up",
                                 },
                             ],
                         },

From 2ca22c127a69fe97999d341224bb9d6e1aafb01b Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Thu, 7 May 2026 19:34:01 +0100
Subject: [PATCH 16/27] Fix typo bug

---
 python/PiFinder/integrator.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index ab110cf15..2e416541b 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -144,8 +144,7 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                     # Push new solved to shared state
                     shared_state.set_solution(solved)
                     shared_state.set_solve_state(True)
-                    print(solved)
-                    last_solve_time = solved["solved_time"]
+                    last_solve_time = solved["solve_time"]
 
     except EOFError:
         logger.error("Main no longer running for integrator")

From 25d4f6e9e20b1931d9bbcad47bfb345ee51a5416 Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Fri, 8 May 2026 23:49:44 +0200
Subject: [PATCH 17/27] Fix: Gave error when location or dt weren't defined

---
 python/PiFinder/integrator.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 2e416541b..f905ef4ef 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -264,7 +264,7 @@ def get_alt_az(RA_deg, Dec_deg, location, dt) -> tuple[float | None, float | Non
     Get Alt/Az from RA/Dec, location and datetime.
     RETURNS: alt_deg, az_deg
     """
-    if RA_deg is None or Dec_deg is None:
+    if RA_deg is None or Dec_deg is None or location is None or dt is None:
         return None, None
     else:
         calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)

From e50cea3a7fbb567e47e0e0278b515e0f234851ab Mon Sep 17 00:00:00 2001
From: Tak Kaneko <>
Date: Sat, 9 May 2026 12:36:44 +0200
Subject: [PATCH 18/27] Move get_roll_by_chart_coord_sys() to chart.py

---
 python/PiFinder/integrator.py | 57 ----------------------------------
 python/PiFinder/ui/chart.py   | 58 +++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 57 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index f905ef4ef..7713d35a4 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -135,11 +135,6 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                                                         shared_state.location(), 
                                                         shared_state.datetime())
 
-                solved["Roll"] = get_roll_by_chart_coord_sys(solved["RA"], solved["Dec"], 
-                                                                chart_coord_sys=cfg.get_option("chart_coord_sys"),
-                                                                location=shared_state.location(), 
-                                                                dt=shared_state.datetime())
-                
                 if (solved["RA"] is not None) and (solved["Dec"] is not None):
                     # Push new solved to shared state
                     shared_state.set_solution(solved)
@@ -271,58 +266,6 @@ def get_alt_az(RA_deg, Dec_deg, location, dt) -> tuple[float | None, float | Non
         return calc_utils.sf_utils.radec_to_altaz(RA_deg, Dec_deg, dt)
 
 
-def get_roll_by_chart_coord_sys(
-    ra_deg: float,  # Right Ascension of the target in degrees
-    dec_deg: float,  # Declination of the target in degrees
-    chart_coord_sys: str,  # "Alt/Az" or "EQ"
-    location=None,  # astropy EarthLocation object or None
-    dt: datetime.datetime | None = None,  # datetime object or None
-) -> float:
-    """
-    Returns the roll (in degrees) depending on the configured chart coordinate
-    system. The RA and Dec of the target should be provided (in degrees).
-
-    * horiz: Display the chart in the horizontal coordinate so that up in the
-      chart points to the Zenith.
-    * EQ (Auto): Display the chart in the equatorial coordinate system.
-      Automatically select NCP or SCP-up based on location.
-    * EQ (North-up), EQ (South-up): Display chart in the equatorial coordinate
-      system with NCP or SCP up.
-
-    Assumes that location has already been set in calc_utils.sf_utils.
-    # TODO: Move this to chart.py
-    """
-    if (ra_deg is None) or (dec_deg is None):
-        return None  # Can't calculate roll without RA/Dec
-
-    if chart_coord_sys == "horiz":
-        # Horizontal coordinates (alt/az):
-        if location and dt:
-            calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
-            # chart.py uses roll to rotate the chart around the target center
-            # by roll in anti-clockwise direction. Use -parallactic_angle
-            roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
-        else:
-            # No position or time/date available. Default to display in equatorial coordinate
-            roll_deg = 0.0  # NCP up
-    elif chart_coord_sys == "eq_auto":
-        # Equatorial coordinates: (North-up/south-up depending on latitude)
-        roll_deg = 0.0  # Default (NCP up)
-        # If location is available, adjust roll for hemisphere:
-        if location:
-            if location.lat < 0.0:
-                roll_deg = 180.0  # SCP up (for southern hemisphere)
-    elif chart_coord_sys == "eq_north_up":
-        roll_deg = 0.0
-    elif chart_coord_sys == "eq_south_up":
-        roll_deg = 180.0
-    else:
-        logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
-        roll_deg = 0.0  # NCP up
-
-    return roll_deg
-
-
 def set_cam2scope_alignment(imu_dead_reckoning: ImuDeadReckoning, solved: dict):
     """
     Set alignment.
diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index 670e9c61e..d5e16f0cc 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -157,6 +157,13 @@ def update(self, force=False):
                 self.plot_no_solve()
             elif self.solution_is_new(last_solve_time):
                 # Solution is new so plot the updated chart
+                self.solution["Roll"] = self._get_roll_by_chart_coord_sys(
+                    self.solution["RA"], self.solution["Dec"], 
+                    chart_coord_sys=self.config_object.get_option("chart_coord_sys"),
+                    location=self.shared_state.location(), 
+                    dt=self.shared_state.datetime()  # TODO used solution["solve_time"]?
+                )
+
                 # This needs to be called first to set RA/DEC/ROLL
                 image_obj, _visible_stars = self.starfield.plot_starfield(
                     self.solution["RA"],
@@ -263,3 +270,54 @@ def key_square(self):
         self.fov_index = 1
         self.set_fov(self.fov_list[self.fov_index])
         self.update()
+
+    def _get_roll_by_chart_coord_sys(
+        ra_deg: float,  # Right Ascension of the target in degrees
+        dec_deg: float,  # Declination of the target in degrees
+        chart_coord_sys: str,  # "Alt/Az" or "EQ"
+        location=None,  # astropy EarthLocation object or None
+        dt: datetime.datetime | None = None,  # datetime object or None
+    ) -> float:
+        """
+        Returns the roll (in degrees) depending on the configured chart coordinate
+        system. The RA and Dec of the target should be provided (in degrees).
+
+        * horiz: Display the chart in the horizontal coordinate so that up in the
+        chart points to the Zenith.
+        * EQ (Auto): Display the chart in the equatorial coordinate system.
+        Automatically select NCP or SCP-up based on location.
+        * EQ (North-up), EQ (South-up): Display chart in the equatorial coordinate
+        system with NCP or SCP up.
+
+        Assumes that location has already been set in calc_utils.sf_utils.
+        # TODO: Move this to chart.py
+        """
+        if (ra_deg is None) or (dec_deg is None):
+            return None  # Can't calculate roll without RA/Dec
+
+        if chart_coord_sys == "horiz":
+            # Horizontal coordinates (alt/az):
+            if location and dt:
+                calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
+                # chart.py uses roll to rotate the chart around the target center
+                # by roll in anti-clockwise direction. Use -parallactic_angle
+                roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
+            else:
+                # No position or time/date available. Default to display in equatorial coordinate
+                roll_deg = 0.0  # NCP up
+        elif chart_coord_sys == "eq_auto":
+            # Equatorial coordinates: (North-up/south-up depending on latitude)
+            roll_deg = 0.0  # Default (NCP up)
+            # If location is available, adjust roll for hemisphere:
+            if location:
+                if location.lat < 0.0:
+                    roll_deg = 180.0  # SCP up (for southern hemisphere)
+        elif chart_coord_sys == "eq_north_up":
+            roll_deg = 0.0
+        elif chart_coord_sys == "eq_south_up":
+            roll_deg = 180.0
+        else:
+            logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
+            roll_deg = 0.0  # NCP up
+
+        return roll_deg
\ No newline at end of file

From 4ffcb8f7bc1b550f8c6b79780c08ab5c1a38f629 Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 20:50:38 +0100
Subject: [PATCH 19/27] Fix bug

---
 python/PiFinder/ui/chart.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index d5e16f0cc..a89f1e9bd 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -271,7 +271,7 @@ def key_square(self):
         self.set_fov(self.fov_list[self.fov_index])
         self.update()
 
-    def _get_roll_by_chart_coord_sys(
+    def _get_roll_by_chart_coord_sys(self,
         ra_deg: float,  # Right Ascension of the target in degrees
         dec_deg: float,  # Declination of the target in degrees
         chart_coord_sys: str,  # "Alt/Az" or "EQ"

From a4e71e3458427781056668310e9e95c961d418f6 Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 20:51:16 +0100
Subject: [PATCH 20/27] Refactor

---
 python/PiFinder/integrator.py |  1 -
 python/PiFinder/ui/chart.py   | 12 ++++++------
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 7713d35a4..c0424880e 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -15,7 +15,6 @@
 """
 from __future__ import annotations  # To support | in typehints (remove this for Python 3.10+)
 
-import datetime
 import queue
 import time
 import copy
diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index a89f1e9bd..3b6ae42eb 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -5,7 +5,9 @@
 This module contains the chart (starfield + constellation lines) UI Module class
 
 """
+from __future__ import annotations  # To support | in typehints (remove this for Python 3.10+)
 
+import datetime
 import time
 from PIL import ImageChops, Image
 
@@ -163,7 +165,6 @@ def update(self, force=False):
                     location=self.shared_state.location(), 
                     dt=self.shared_state.datetime()  # TODO used solution["solve_time"]?
                 )
-
                 # This needs to be called first to set RA/DEC/ROLL
                 image_obj, _visible_stars = self.starfield.plot_starfield(
                     self.solution["RA"],
@@ -274,9 +275,9 @@ def key_square(self):
     def _get_roll_by_chart_coord_sys(self,
         ra_deg: float,  # Right Ascension of the target in degrees
         dec_deg: float,  # Declination of the target in degrees
-        chart_coord_sys: str,  # "Alt/Az" or "EQ"
-        location=None,  # astropy EarthLocation object or None
-        dt: datetime.datetime | None = None,  # datetime object or None
+        chart_coord_sys: str,
+        location=None,
+        dt: datetime.datetime | None = None,
     ) -> float:
         """
         Returns the roll (in degrees) depending on the configured chart coordinate
@@ -290,7 +291,6 @@ def _get_roll_by_chart_coord_sys(self,
         system with NCP or SCP up.
 
         Assumes that location has already been set in calc_utils.sf_utils.
-        # TODO: Move this to chart.py
         """
         if (ra_deg is None) or (dec_deg is None):
             return None  # Can't calculate roll without RA/Dec
@@ -320,4 +320,4 @@ def _get_roll_by_chart_coord_sys(self,
             logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
             roll_deg = 0.0  # NCP up
 
-        return roll_deg
\ No newline at end of file
+        return roll_deg

From 790fc24add93fb8813177a8d4e683579736792f6 Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 20:59:24 +0100
Subject: [PATCH 21/27] Make get_roll_by_chart_coord_sys() a func

---
 python/PiFinder/ui/chart.py | 94 +++++++++++++++++++------------------
 1 file changed, 48 insertions(+), 46 deletions(-)

diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index 3b6ae42eb..1f101fd73 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -159,7 +159,7 @@ def update(self, force=False):
                 self.plot_no_solve()
             elif self.solution_is_new(last_solve_time):
                 # Solution is new so plot the updated chart
-                self.solution["Roll"] = self._get_roll_by_chart_coord_sys(
+                self.solution["Roll"] = get_roll_by_chart_coord_sys(
                     self.solution["RA"], self.solution["Dec"], 
                     chart_coord_sys=self.config_object.get_option("chart_coord_sys"),
                     location=self.shared_state.location(), 
@@ -272,52 +272,54 @@ def key_square(self):
         self.set_fov(self.fov_list[self.fov_index])
         self.update()
 
-    def _get_roll_by_chart_coord_sys(self,
-        ra_deg: float,  # Right Ascension of the target in degrees
-        dec_deg: float,  # Declination of the target in degrees
-        chart_coord_sys: str,
-        location=None,
-        dt: datetime.datetime | None = None,
-    ) -> float:
-        """
-        Returns the roll (in degrees) depending on the configured chart coordinate
-        system. The RA and Dec of the target should be provided (in degrees).
 
-        * horiz: Display the chart in the horizontal coordinate so that up in the
-        chart points to the Zenith.
-        * EQ (Auto): Display the chart in the equatorial coordinate system.
-        Automatically select NCP or SCP-up based on location.
-        * EQ (North-up), EQ (South-up): Display chart in the equatorial coordinate
-        system with NCP or SCP up.
 
-        Assumes that location has already been set in calc_utils.sf_utils.
-        """
-        if (ra_deg is None) or (dec_deg is None):
-            return None  # Can't calculate roll without RA/Dec
-
-        if chart_coord_sys == "horiz":
-            # Horizontal coordinates (alt/az):
-            if location and dt:
-                calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
-                # chart.py uses roll to rotate the chart around the target center
-                # by roll in anti-clockwise direction. Use -parallactic_angle
-                roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
-            else:
-                # No position or time/date available. Default to display in equatorial coordinate
-                roll_deg = 0.0  # NCP up
-        elif chart_coord_sys == "eq_auto":
-            # Equatorial coordinates: (North-up/south-up depending on latitude)
-            roll_deg = 0.0  # Default (NCP up)
-            # If location is available, adjust roll for hemisphere:
-            if location:
-                if location.lat < 0.0:
-                    roll_deg = 180.0  # SCP up (for southern hemisphere)
-        elif chart_coord_sys == "eq_north_up":
-            roll_deg = 0.0
-        elif chart_coord_sys == "eq_south_up":
-            roll_deg = 180.0
+def get_roll_by_chart_coord_sys(
+    ra_deg: float,  # Right Ascension of the target in degrees
+    dec_deg: float,  # Declination of the target in degrees
+    chart_coord_sys: str,
+    location=None,
+    dt: datetime.datetime | None = None,
+) -> float:
+    """
+    Returns the roll (in degrees) depending on the configured chart coordinate
+    system. The RA and Dec of the target should be provided (in degrees).
+
+    * horiz: Display the chart in the horizontal coordinate so that up in the
+    chart points to the Zenith.
+    * EQ (Auto): Display the chart in the equatorial coordinate system.
+    Automatically select NCP or SCP-up based on location.
+    * EQ (North-up), EQ (South-up): Display chart in the equatorial coordinate
+    system with NCP or SCP up.
+
+    Assumes that location has already been set in calc_utils.sf_utils.
+    """
+    if (ra_deg is None) or (dec_deg is None):
+        return None  # Can't calculate roll without RA/Dec
+
+    if chart_coord_sys == "horiz":
+        # Horizontal coordinates (alt/az):
+        if location and dt:
+            calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
+            # chart.py uses roll to rotate the chart around the target center
+            # by roll in anti-clockwise direction. Use -parallactic_angle
+            roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
         else:
-            logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
+            # No position or time/date available. Default to display in equatorial coordinate
             roll_deg = 0.0  # NCP up
-
-        return roll_deg
+    elif chart_coord_sys == "eq_auto":
+        # Equatorial coordinates: (North-up/south-up depending on latitude)
+        roll_deg = 0.0  # Default (NCP up)
+        # If location is available, adjust roll for hemisphere:
+        if location:
+            if location.lat < 0.0:
+                roll_deg = 180.0  # SCP up (for southern hemisphere)
+    elif chart_coord_sys == "eq_north_up":
+        roll_deg = 0.0
+    elif chart_coord_sys == "eq_south_up":
+        roll_deg = 180.0
+    else:
+        logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
+        roll_deg = 0.0  # NCP up
+
+    return roll_deg

From 79762267b6225afbc48072b4afd74a8aab636d0c Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 21:11:38 +0100
Subject: [PATCH 22/27] Rename roll --> chart_rotation_angle

---
 python/PiFinder/ui/chart.py | 38 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index 1f101fd73..c3a6bb2d8 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -159,17 +159,17 @@ def update(self, force=False):
                 self.plot_no_solve()
             elif self.solution_is_new(last_solve_time):
                 # Solution is new so plot the updated chart
-                self.solution["Roll"] = get_roll_by_chart_coord_sys(
+                chart_rot_angle = get_chart_rotation_angle(
                     self.solution["RA"], self.solution["Dec"], 
                     chart_coord_sys=self.config_object.get_option("chart_coord_sys"),
                     location=self.shared_state.location(), 
                     dt=self.shared_state.datetime()  # TODO used solution["solve_time"]?
                 )
-                # This needs to be called first to set RA/DEC/ROLL
+                # This needs to be called first to set RA/DEC/rot_angle
                 image_obj, _visible_stars = self.starfield.plot_starfield(
                     self.solution["RA"],
                     self.solution["Dec"],
-                    self.solution["Roll"],
+                    chart_rot_angle,
                     constellation_brightness,
                 )
                 image_obj = ImageChops.multiply(
@@ -274,7 +274,7 @@ def key_square(self):
 
 
 
-def get_roll_by_chart_coord_sys(
+def get_chart_rotation_angle(
     ra_deg: float,  # Right Ascension of the target in degrees
     dec_deg: float,  # Declination of the target in degrees
     chart_coord_sys: str,
@@ -282,8 +282,10 @@ def get_roll_by_chart_coord_sys(
     dt: datetime.datetime | None = None,
 ) -> float:
     """
-    Returns the roll (in degrees) depending on the configured chart coordinate
-    system. The RA and Dec of the target should be provided (in degrees).
+    Returns angle (in degrees) to rotate the chart by depending on the 
+    configured chart coordinate system. This was previously called "roll". 
+    Chart will be plotted rotated around (RA, Dec); +ve means anti-clockwise 
+    rotation. The RA and Dec of the target should be provided (in degrees).
 
     * horiz: Display the chart in the horizontal coordinate so that up in the
     chart points to the Zenith.
@@ -291,35 +293,31 @@ def get_roll_by_chart_coord_sys(
     Automatically select NCP or SCP-up based on location.
     * EQ (North-up), EQ (South-up): Display chart in the equatorial coordinate
     system with NCP or SCP up.
-
-    Assumes that location has already been set in calc_utils.sf_utils.
     """
     if (ra_deg is None) or (dec_deg is None):
-        return None  # Can't calculate roll without RA/Dec
+        return None  # Can't calculate without RA/Dec
 
     if chart_coord_sys == "horiz":
         # Horizontal coordinates (alt/az):
         if location and dt:
             calc_utils.sf_utils.set_location(location.lat, location.lon, location.altitude)
-            # chart.py uses roll to rotate the chart around the target center
-            # by roll in anti-clockwise direction. Use -parallactic_angle
-            roll_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
+            # Use -parallactic_angle
+            rot_deg = -calc_utils.sf_utils.radec_to_pa(ra_deg, dec_deg, dt)
         else:
             # No position or time/date available. Default to display in equatorial coordinate
-            roll_deg = 0.0  # NCP up
+            rot_deg = 0.0  # NCP up
     elif chart_coord_sys == "eq_auto":
         # Equatorial coordinates: (North-up/south-up depending on latitude)
-        roll_deg = 0.0  # Default (NCP up)
-        # If location is available, adjust roll for hemisphere:
+        rot_deg = 0.0  # NCP up (default & northern hemisphere)
         if location:
             if location.lat < 0.0:
-                roll_deg = 180.0  # SCP up (for southern hemisphere)
+                rot_deg = 180.0  # SCP up (for southern hemisphere)
     elif chart_coord_sys == "eq_north_up":
-        roll_deg = 0.0
+        rot_deg = 0.0
     elif chart_coord_sys == "eq_south_up":
-        roll_deg = 180.0
+        rot_deg = 180.0
     else:
         logger.error(f"Unknown chart coordinate system: {chart_coord_sys}. Defaulting to EQ North-up.")
-        roll_deg = 0.0  # NCP up
+        rot_deg = 0.0  # NCP up
 
-    return roll_deg
+    return rot_deg

From c49c8f2916398dbfdef28509998573b1a3d9e67d Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 21:13:58 +0100
Subject: [PATCH 23/27] Roll is not needed

---
 python/PiFinder/ui/chart.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index c3a6bb2d8..c08bb91ac 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -243,8 +243,7 @@ def solution_is_new(self, last_solve_time):
         if last_solve_time <= self.last_update:
             return False
         if (
-            self.solution["Roll"] is None
-            or self.solution["RA"] is None
+            self.solution["RA"] is None
             or self.solution["Dec"] is None
         ):
             return False

From 610c9ebca1c8b4ea0b381b2d1e75e84e306e6a6d Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 21:17:28 +0100
Subject: [PATCH 24/27] Edit comments

---
 python/PiFinder/integrator.py | 2 +-
 python/PiFinder/ui/chart.py   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index c0424880e..598d8cb9f 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -124,7 +124,7 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                     update_imu(imu_dead_reckoning, solved, last_image_solve, imu)
                     pointing_updated = True
 
-            # Update Alt, Az, Roll only if newer than last push
+            # Update Alt, Az only if newer than last push
             if pointing_updated and solved["solve_time"] > last_solve_time:
                 solved["constellation"] = get_constellation(solved["RA"], solved["Dec"])
 
diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index c08bb91ac..b2ed3024b 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -163,9 +163,9 @@ def update(self, force=False):
                     self.solution["RA"], self.solution["Dec"], 
                     chart_coord_sys=self.config_object.get_option("chart_coord_sys"),
                     location=self.shared_state.location(), 
-                    dt=self.shared_state.datetime()  # TODO used solution["solve_time"]?
+                    dt=self.shared_state.datetime()
                 )
-                # This needs to be called first to set RA/DEC/rot_angle
+                # This needs to be called first to set RA/DEC/chart_rot_angle
                 image_obj, _visible_stars = self.starfield.plot_starfield(
                     self.solution["RA"],
                     self.solution["Dec"],

From 68b6d788a2f511e4d67353e6c898bc4fda89c8fd Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 21:27:09 +0100
Subject: [PATCH 25/27] align.py: Re-use get_chart_rotation_angle()

---
 python/PiFinder/ui/align.py | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/python/PiFinder/ui/align.py b/python/PiFinder/ui/align.py
index 976ea37c5..71f9aa8b1 100644
--- a/python/PiFinder/ui/align.py
+++ b/python/PiFinder/ui/align.py
@@ -14,6 +14,7 @@
 from PiFinder.ui.marking_menus import MarkingMenuOption, MarkingMenu
 from PiFinder import plot
 from PiFinder.ui.base import UIModule
+from PiFinder.ui.chart import get_chart_rotation_angle
 
 
 def align_on_radec(ra, dec, command_queues, config_object, shared_state) -> bool:
@@ -215,26 +216,25 @@ def update(self, force=False):
             last_solve_time = self.solution["solve_time"]
 
             if self.solution_is_new(last_solve_time) or force:
-                # This needs to be called first to set RA/DEC/ROLL
                 if self.align_mode:
                     # We want to use the CAMERA solve as
                     # it's not updated by the IMU and we'll be moving
                     # the reticle to the star
-                    image_obj, self.visible_stars = self.starfield.plot_starfield(
-                        self.solution["camera_solve"]["RA"],
-                        self.solution["camera_solve"]["Dec"],
-                        self.solution["camera_solve"]["Roll"],
-                        constellation_brightness,
-                        shade_frustrum=True,
-                    )
+                    chart_center = self.solution["camera_solve"]
                 else:
-                    image_obj, self.visible_stars = self.starfield.plot_starfield(
-                        self.solution["camera_center"]["RA"],
-                        self.solution["camera_center"]["Dec"],
-                        self.solution["camera_center"]["Roll"],
-                        constellation_brightness,
-                        shade_frustrum=True,
-                    )
+                    chart_center = self.solution["camera_center"]
+
+                chart_rot_angle = get_chart_rotation_angle(
+                    chart_center["RA"], chart_center["Dec"], 
+                    chart_coord_sys=self.config_object.get_option("chart_coord_sys"),
+                    location=self.shared_state.location(), 
+                    dt=self.shared_state.datetime()
+                )
+                # This needs to be called first to set RA/DEC/chart_rot_angle
+                image_obj, self.visible_stars = self.starfield.plot_starfield(
+                        chart_center["RA"], chart_center["Dec"], chart_rot_angle, 
+                        constellation_brightness, shade_frustrum=True,
+                )
 
                 image_obj = ImageChops.multiply(
                     image_obj.convert("RGB"), self.colors.red_image
@@ -454,8 +454,7 @@ def solution_is_new(self, last_solve_time):
         if last_solve_time <= self.last_update:
             return False
         if (
-            self.solution["Roll"] is None
-            or self.solution["RA"] is None
+            self.solution["RA"] is None
             or self.solution["Dec"] is None
         ):
             return False

From 0206f1ccef8c57c081c0a9339f739a3086d8ebcf Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 21:29:32 +0100
Subject: [PATCH 26/27] menu: Move chart_coordinate_sys further up

---
 python/PiFinder/ui/menu_structure.py | 48 ++++++++++++++--------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/python/PiFinder/ui/menu_structure.py b/python/PiFinder/ui/menu_structure.py
index c6e69a90a..6a4f15bd9 100644
--- a/python/PiFinder/ui/menu_structure.py
+++ b/python/PiFinder/ui/menu_structure.py
@@ -771,6 +771,30 @@ def _(key: str) -> Any:
                     "select": "single",
                     "label": "chart_settings",
                     "items": [
+                                                {
+                            "name": _("Coordinate Sys."),
+                            "class": UITextMenu,
+                            "select": "single",
+                            "config_option": "chart_coord_sys",
+                            "items": [
+                                {
+                                    "name": _("Horizontal"),
+                                    "value": "horiz",
+                                },
+                                {
+                                    "name": _("EQ (Auto)"),
+                                    "value": "eq_auto",
+                                },
+                                {
+                                    "name": _("EQ (North-up)"),
+                                    "value": "eq_north_up",
+                                },
+                                {
+                                    "name": _("EQ (South-up)"),
+                                    "value": "eq_south_up",
+                                },
+                            ],
+                        },
                         {
                             "name": _("Reticle"),
                             "class": UITextMenu,
@@ -863,30 +887,6 @@ def _(key: str) -> Any:
                                 },
                             ],
                         },
-                        {
-                            "name": _("Coordinate Sys."),
-                            "class": UITextMenu,
-                            "select": "single",
-                            "config_option": "chart_coord_sys",
-                            "items": [
-                                {
-                                    "name": _("Horizontal"),
-                                    "value": "horiz",
-                                },
-                                {
-                                    "name": _("EQ (Auto)"),
-                                    "value": "eq_auto",
-                                },
-                                {
-                                    "name": _("EQ (North-up)"),
-                                    "value": "eq_north_up",
-                                },
-                                {
-                                    "name": _("EQ (South-up)"),
-                                    "value": "eq_south_up",
-                                },
-                            ],
-                        },
                     ],
                 },
                 {

From bce95905266aae0a3870b01670bd25890dae569f Mon Sep 17 00:00:00 2001
From: TakKanekoGit <>
Date: Sat, 9 May 2026 22:03:41 +0100
Subject: [PATCH 27/27] Fix logger issue - flagged up by nox lint check

---
 python/PiFinder/ui/chart.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/python/PiFinder/ui/chart.py b/python/PiFinder/ui/chart.py
index b2ed3024b..55349f689 100644
--- a/python/PiFinder/ui/chart.py
+++ b/python/PiFinder/ui/chart.py
@@ -8,6 +8,7 @@
 from __future__ import annotations  # To support | in typehints (remove this for Python 3.10+)
 
 import datetime
+import logging
 import time
 from PIL import ImageChops, Image
 
@@ -18,6 +19,9 @@
 from PiFinder import calc_utils
 
 
+logger = logging.getLogger("Chart")
+
+
 class UIChart(UIModule):
     __title__ = "CHART"
     __help_name__ = "chart"