CRC reception error in FSK reception on nucleo WL55JC1 when payload length changes

[roberto-chiarini]

Hello community,

I've developing a set of products based on MCU STM32WLE5.

The devices communicates using FSK modulation and a variable payload.

To test the system I've bought two NUCLEO WL55JC1 and modifying the PER examples I've prepared two project, one for the master and one for the slave. Each device transmit and reply.

What I've seen is that when I press the button and change the payload length, the transmission seems to be ok, but the reception fails with a CRC error, as it would expect a message with a length equals to the transmitted message. The next messages then are transmitted and received without any error.

I attach the screenshot of serial logs and the two projects:

• Screenshot 2024-04-23 103703.png: screenshot of serial logs (master on the left, slave on the right);
• SubGHz_Phy_Per_Master.7z: compressed project of master device;
• SubGHz_Phy_Per_Slave.7z: compressed project of slave device.

I cannot understand what is wrong in my projects.

Any help would be appreciated.

Thanks

Roberto

[roberto-chiarini]

I attached two more screenshots:

• Screenshot 2024-04-23 103647.png: full screenshot of serial logs when error occurs (master on the left, slave on the right);
• Screenshot 2024-04-23 103425.png: full screenshot of serial logs when communication is ok (master on the left, slave on the right).