Lora node [B-L072Z-LRWAN] is not transmitting signal, unless its connected to spi

i am working with B-L072Z-LRWAN as my end node, i have registered my device and im getting uplink signal in ttn console. but the problem is my node is transmitting the signal only when it have spi connection. when it starts normally with battery power its not transmitting any signal to gateway.

I guess this is not the problem of the server since, as you mentioned, it works when it is connected to the SPI. So the server works. your problem is on the end-device’s side.

Are you using arduino?

In that case you need to check if your arduino code (the .INO file) has something like this:

while(!Serial) ; // Empty while body

This waits for the serial console to be connected. Otherwise it will never start the loop process.

thanks for the quick reply,
I am following STM32 lora configuring, using i-cube-lorawan with keil uvision.

You’re going to need to debug your firmware and hardware.

What does “connected to SPI” even mean in this case? What would you connect to SPI? Figure that out, and it gives you a clue where the difficulty is. Probably the software is waiting for something, for example if it is supposed to report sensor readings it may not even try to operate the radio until it has obtained a sensor reading via SPI.

It doesn’t seem clear how anyone could help you right now

i have connected my pc to node via spi, so i can access node using tera term. by so far i have done debugging and still the problem is same.

Are you sure? That is possible, but highly unusual and there is no way anyone can help you at all unless you provide full detail of the connection, how it is implemented, and share the code that deals with it on the node side.

Does teraterm even speak SPI??? Using what sort of interface on the PC?

Far more common is a serial or serial-over-USB debug interface to a PC…