RAK WisBlock 4631 crashes or won’t start when running firmware v1.13.0

[Emmpunkt]

Description:
After running my RAK 4631 as a repeater for 9 days without issues, the device suddenly stopped working. It no longer boots reliably. I attempted several restarts and reflashed the firmware multiple times. I also erased the flash completely and tested older firmware versions.

Findings so far:

• Firmware 1.13.0 → device does not start or crashes immediately
• Firmware 1.12.x → same issue
• Firmware 1.11.0 → device works normally again
• Battery voltage is 4.11 V, so low power should not be the cause
• Device behaves as if it is stuck in sleep mode
  Question:
  Has anyone experienced similar issues with firmware 1.13.0 on the RAK 4631?
  Any hints on what might cause the device to fail after running for several days?

I went down to 1.10. because of an other Issue. (BME260)

[IoTThinks]

Do you use the CLI "powersaving on"?

[Emmpunkt]

Yes, i had "powersavings on" , but switched it off before downgrading

[IoTThinks]

So "powersaving on" is not the issue.
Firmware 1.13.0 → device does not start or crashes immediately

Do you wire your battery to battery pads or via usb-c?
You may tell us how you do the wiring from panel to board to battery.

[Emmpunkt]

I´m using the battery-plug, the solar-plug is not used.
If i unplug the battery and use usb-c, it starts (as i remember ;) ) If it helps you, i will check it again to be shure...

Wiring:
Solar panel -> CN3795 (MPPT-Charger) -> Battery
Battery -> Battery Plug

The thing that i don´t understand:
It was running for 9 days. I remember that this happend before with 1.12 or 1.11, but was something like 14 days. But there was a low battery and after charging and resetting it was working again.
But now, even with deleting the flash, i was not able to start it again. Is there something staying in the memory even with emty flash?

[IoTThinks]

Wiring: Solar panel -> CN3795 (MPPT-Charger) -> Battery
Battery -> Battery Plug

This setup should be fine for NRF52 Power Saving management in 1.13 as you wire Battery -> Battery Plug
Have you check the Battery plug connection? It may loose.

[Emmpunkt]

The (silikon) wires where soldered directly to the pins because i had not space in my box. But i put a connector inline yesterday after this happened.
The measured voltage was OK. Measured directly on the pins.
The voltage shown in the app shows nearly the same.
Also the 3.3v was fine...

[IoTThinks]

I will simulate your case with my power supply tomorrow.

In the meantime, you may use this bin for your RAK.
I set the bootlock voltage of NRF52 power management from 3.3v down to 1.8v.
https://github.com/IoTThinks/EasySkyMesh/releases/tag/PowerSaving13

[Emmpunkt]

No, its dead again.
Because i have to take it inside now:
Anything i can check or measure?

Further testing:
All tried verions boot with USB connected.
Ver. 1.12, 1.13 don´t boot on battery. 1.11 does.
Measured battery voltage: 4.20V
App battery voltage: 4.16V
3,3V is 3.302V

[JPurp]

If this helps I have a similar issue. RAK 4631 running Repeater FW v1.13.0 it will not boot via battery. The battery is connected via the RAK 19003 battery port, the battery is >4V. If I connect USB the board boots. I tested this across multiple RAK 4631 and same results.

As a control I flashed BLE FW v1.13.0 to one of the board that was failing running Repeater FW and it operates normally via battery, USB or USB & battery.

This appears to be an issue with the Repeater FW.

-JP

[weebl2000]

Just out of curiosity, could you try my latest dev_plus firmware? https://mcimages.weebl.me?commitId=dev_plus - if it still crashes with this, I can have a look at what might cause the crashes. Do you have debug logging?

[IoTThinks]

@weebl2000 Since MC 1.12, I remember DC2DC is applied as default.
No idea if this is related to the issue.

[weebl2000]

@JPurp Please try this firmware: https://mcimages.weebl.me?commitId=fix-rak4631-boot - it's latest dev and hopefully fixes the boot issue.

[Emmpunkt]

I tried both versions, it does not boot.
If i enable debug logging, how do i get the log?

[weebl2000]

I tried both versions, it does not boot. If i enable debug logging, how do i get the log?

Connect the device with USB and read the serial output. Are you on Windows/Linux/Mac?

[Emmpunkt]

I´m on windows.
If i connect it via USB, i have to start it to get a connection. It runs on USB but not on battery. So how can i get a USB connection without powering the device over usb?