STM32WL55JC1 is not sending or receiving

[AHakk.1]

Hello everyone, I am using 3 STM32WL55JC1. One for base station and the other two's for sensor node. Everything was fine but then I started UART communication between base station and ESP32. I started coding ESP32 so I unplug the usb cables of stm32wl55jc1 (base station) but GND-GND, RX-TX , TX-RX is still plugged between base station and esp32. After a while, I realize my STM32WL55JC1's lora is not working. I can't send anything and I can't receive anything but microcontroller still working. I don't know why it is happening. Any idea ?

[IIRHO.1]

Hello @AHakk.1 and welcome to ST Community.

I suggest you should check whether the power settings are stable and sufficient for the operation. To do this, you have to compare them before and after unplugging the USB cable.

When your question is answered, please close this topic by choosing "Accept as Solution". This will help other users find that answer faster.

Issam

[AHakk.1]

Okay thank you. I have 3 stm32wl55jc1 module. 2 of them working with out problem as end node or base station.  One of them is not working either node or base station. This module's microcontroller works but as I said lora is not working. I don't understand what happened lora part. 

[IIRHO.1]

Hello again

I suggest you to reset them all.  This may help to clear any interference that may have occurred.

Best regards.

Issam

[IIRHO.1]

Hello again,

They are maybe sending both in the same time using the same channel that's why you can see just one of them. Can you try to stop the one who works fine and take a look if the other is sending fine or not.

Best Regards.

Issam

[AHakk.1]

One of them (broken one) does not send when alone or together but I can see this on serial port.  

 Sensor start -> ID=01 , RF=868000000MHz , SF=7 , CS=-80dBm
 -> 0s134:RF Channel Sensing #1 ... CS: -128dBm , CS time: 10ms 

[IIRHO.1]

Hello again,

Can you erase and flash the code again for the broken one. If you still  have the same problem, I suggest you to use the ping pong example to test the broken board.

Best Regards.

Issam

Best Regards.

[harryrex]

One of them serves as a base station, and the other two are acting as sensor nodes. Everything was running smoothly until I started implementing UART communication between the base station and an ESP32. While I was coding for the ESP32, I disconnected the USB cables from the STM32WL55JC1 (base station), but I left the GND-GND, RX-TX, and TX-RX connections between the base station and the ESP32 intact. 
https://pinterestvideodownloader.io/

[Issamos]

Hello @harryrex and welcome to ST Community.

I suggest you to do restart to your base station.

Hope this is helpful. 

II