We are using RAK3172 on a custom prototype board, and we are powering it steadily with 3.3VDC. It uses 1.0.2 firmware version and we are using UART2 9600 for comms. Below is the schematic of the board, notice that there is a RC filter on RST pin as suggested in datasheet, in order to keep RST on high (1) level
We have encountered the following problem : After some days of continuous (normal) function , RAK3172 module randomly gets unresponsive in AT commands. After inspection we found that when it reached the “freezed” state, UART2_TX and RST pin were driven at low (0) level by the module itself. It only recovers if we power-cycle the module or momentarily short the RST to 3.3. We have noticed the same problem on several RAK3172 modules.
Do you have any suggestions? Is this a SW or a HW issue ?
Thank you in advance