RAK19003: Battery and solar with meshtastic?

WisBlock
1

Im wondering if full batt+solar plugs in the rak19003 should work with mashtastic firmware?

I have a rak19003 board that has a 4630 module in it, running meshtastic. I have a 3.7v lithium battery, 3000mah, plugged into the BATT, verifying polarity as per the diagram in the user manual where GND is the pin closest to the edge of the board.

With the USB connected, everything works, even get this on the serial port:
DEBUG | ??:??:?? 606 [Power] Battery: usbPower=1, isCharging=1, batMv=3996, batPct=81

But if I unplug the USB everything seemengly dies; if i then unplug the batt and plug it back in then the greed led (different led than the red) comes on for a few secs then turns off. I can RST and the process starts back over. A double RST has the green LED pulsating.

The red led never does a thing through this process after the USB is removed.

Even with the green LED off (and the red off) I can use a flipperzero and DAP and pyocd to query it, so it does seem to be alive:

(.venv) me@HomePC:~/rak-recovery$ pyocd list --targets | grep -i nrf52840

  nrf52840                  Nordic Semiconductor     NRF52840                                    builtin  
  nrf52840_xxaa             Nordic Semiconductor     nRF52840_xxAA                nRF52 Series   pack

With no USB connected, on the RAK4630’s pads I see 3.3v as expected, and on the RAK190003 I see a good 3.9v.

Bad board, or just not supported in meshtastic?

2

The 3.9V on the 19003 and stable 3.3V at the module pads with USB removed point to the power path working, so I would not call the board bad yet. The green LED blip and dead red LED sound more like the firmware booting into a state where it is not fully initializing without USB. Meshtastic support for RAK19003 plus solar charging has been patchy, and some builds handle the battery-only boot poorly. Worth checking your firmware version and whether the board is set to the correct variant; a serial log captured right after unplugging USB would show where it stalls.

3

The 3.9V on the 19003 and 3.3V at the module pads rule out a dead power path, so I agree it’s worth checking the firmware variant before replacing anything. Since pyocd still sees the nRF52840 with USB removed, the MCU is alive; the question is whether it finishes booting. Capturing a serial log right after unplugging USB would show whether it stalls during power or radio init. Also confirm the board is set to the RAK19003 variant and note the firmware version, since battery-only boot behavior has varied between builds. A 3.7V 3000mAh pack should be fine if polarity is correct.

4

Thanks all - now, I have this when connected to the USB serial port when I do AT+VER=?:
RUI_4.1.1_RAK4631

its a firmware that I found to load on it to revert from meshtastic, not sure it it was the right one for myRAK19003 with the RAK4630 (which shows up on USB as a RAK4631)

I cannot tell from the silkscreen if its a revB or E, the right is cut off, but my UART pads there are labeled TX0, RX0 if that helps, so prob an E? It was ordered Jan 22 2024 if that helps?

But how to " Also confirm the board is set to the RAK19003 variant"?

I tried to use UART-bridge on the flipper to get onto the UART but cannot get any response.

Did I load the wrong firmware back?

5

ok so installing the latest 4630 hex from RAKwireless Firmware Documentation Center: WisGate, WisNode, WisBlock, WisDuo, WisTrio, WisLink did fix both my UART serial issue as well as the battery w/o USB power issue. oddly that website says v4.2.3 but after installing it the AT+VER=? gives me AT+VER=RUI_4.3.0_RAK4631

So i guess the moral of the story here is that this thing wont work on batt with meshtastic then?

Also, Im still confused by " whether the board is set to the correct variant" ?

6

Meshtastic is based on the Arduino/PlatformIO BSP’s using the Arduino SDK.
RUI3 SDK is Arduino compatible, but it is not compatible with Meshtastic.

One of many differences is the bootloader. You cannot flash an application compiled with Arduino/PlatformIO BSP on a device with RUI3 bootloader. And vice versa.

If you want to use Meshtastic, you need to flash the Arduino bootloader first, see here ==> RAK4631 (Arduino BSP) to RAK4631-R (RUI3) Conversion and Vice Versa