Unexplained slowdown of radio in RAK3172 EVB

LPWAN Modules / EVBs RAK3172
#1

Greetings.
We have two RAK1372 EVB on which we are performing tests for an application based on the LoRaWAN End Node sample.
For some reason one of the two evaluation boards (that was working properly as of a few weeks ago when we last used it) is now experiencing a massive slowdown regarding the radio (as an example, where the working board would complete the join procedure in about two seconds, the other board takes upward of forty five seconds) that eventually results in the board resetting itself (likely because of the watchdog).

The only modification done to the hardware was to solder four pins on the RAK5005-O i2c sockets

Is there a way for us to better diagnose (and hopefully fix) this issue?

#2

Hi @I-Fante , welcome back to RAK forum.

Regarding your RAK3172 that takes 45 seconds, that is unusually specially if both modules are at the same setup like same distance to gateway, same antenna, same network server, etc.

Have you tried using the RAK default firmware and check if it has same issue and consistent/repeatable?

#3

Hi.

We have not yey tried the default firmware, though both boards are using the same exact firmware.

#4

ADDENDUM:
We have flashed, using CubeProgrammer, the latest firmware (RUI3 (default baudrate = 115200) and attempted to use the RAK serial port tool.
The device necessitated the use of the 9600 baud rate (despite the flashed firmware being valid for 115200) to get any response but, even with a simple at+ver, it took unusually long (multiple seconds) to receive a response from the device, and even then it was ever only the opening message of the p2p work mode (this image so to speak https://docs.rakwireless.com/assets/images/wisduo/rak3172-evaluation-board/quickstart/p2pworkmode.png)

Furthermore, using the RAK DFU Tool, using 115200 baud rate, went on timeout when trying to flash older versions of the firmware