RAK3172 PB5 and PB6 ports

Hi, all.

I’m having some issues with interrupt in PB6 port. In STM32WLE5CC datasheet, PB6 is a I/O port, but in RAK3172 datasheet, PB6 is only output.

Carl commented in another post (Problems with I2C1 on the RAK3172 module - #2 by carlrowan), that RA3172 PB6 is connected directly on STM32WLE5CC port, without any components.

Is this PIN used for some features in RAK3172 module or in RUI that change the PIN state?

Thank you for your time!

Mario

Welcome to the forum @mariojose

Possible reason:

PB6 is assigned as UART1 TX in RUI3. That means it assigns the pin to the UART drivers and interrupt on this pin already and it might not be possible to use it as generic IO.

I tested successfully PB5, PB12, PB2, PA15, PA9 and PA10 with interrupts. These pins are assigned as GPIO’s in RUI3.

Hi, Bernd! Thank you for your answer!

Yes, this PIN works perfectly as interrupt. I only asked to understand the behavior. We use PB6, PB8, PB9 and PB10 to interrupt when FALLING. When our system start, only PB6 fire interrupt without nothing connected on PIN (all this thin is pulled-down with resistor on our pcb). Maybe when RUI is setting this PIN as TX, it put HIGH-LOW in it before our system start. Probably it is firing the interrupt.

Thank you, again!

Mario