diff --git a/python/PiFinder/integrator.py b/python/PiFinder/integrator.py
index 598d8cb9..6d4bb5c0 100644
--- a/python/PiFinder/integrator.py
+++ b/python/PiFinder/integrator.py
@@ -13,7 +13,10 @@
 - Refactor into class PointingTracker
 
 """
-from __future__ import annotations  # To support | in typehints (remove this for Python 3.10+)
+
+from __future__ import (
+    annotations,
+)  # To support | in typehints (remove this for Python 3.10+)
 
 import queue
 import time
@@ -21,6 +24,7 @@
 import logging
 import numpy as np
 import quaternion  # numpy-quaternion
+import datetime
 
 from PiFinder import config
 from PiFinder import state_utils
@@ -62,7 +66,9 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
         last_solve_time = time.time()
 
         while True:
-            pointing_updated = False  # Flag to track if pointing was updated in this loop
+            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
@@ -108,9 +114,12 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
                     update_plate_solve_and_imu(imu_dead_reckoning, solved)
                     pointing_updated = True
                 else:
+                    # TODO: In this case, it should run update_imu()
                     # Failed solve - clear constellation
                     solved["solve_source"] = "CAM_FAILED"
-                    solved["constellation"] = ""  # NOTE: This gets over-written by IMU dead-reckoning
+                    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)
@@ -121,6 +130,7 @@ 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
 
@@ -128,11 +138,14 @@ def integrator(shared_state, solver_queue, console_queue, log_queue, is_debug=Fa
             if pointing_updated and solved["solve_time"] > last_solve_time:
                 solved["constellation"] = get_constellation(solved["RA"], solved["Dec"])
 
-                # TODO: Altaz doesn't seem to be required for catalogs when in 
+                # 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["Alt"], solved["Az"] = get_alt_az(
+                    solved["RA"],
+                    solved["Dec"],
+                    shared_state.location(),
+                    shared_state.datetime(),
+                )
 
                 if (solved["RA"] is not None) and (solved["Dec"] is not None):
                     # Push new solved to shared state
@@ -146,6 +159,7 @@ 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
@@ -243,6 +257,38 @@ 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 get_constellation(RA_deg, Dec_deg) -> str:
     """
     Get constellation name from the current RA/Dec position.
@@ -285,3 +331,60 @@ def set_cam2scope_alignment(imu_dead_reckoning: ImuDeadReckoning, solved: dict):
 
     # Set alignment in imu_dead_reckoning
     imu_dead_reckoning.set_cam2scope_alignment(solved_cam, solved_scope)
+
+
+def get_roll_by_mount_type(
+    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"
+) -> 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).
+
+    * 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.
+
+    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 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
+        # 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  # NCP up
+
+    return roll_deg