Device not wake up after RTC-time and send message with Lora P2P.

[Leinad1514]

I would like to use my ST32 to send data from one location to another. For this purpose, it should sleep in Stop Mode 2 for a fixed period, then wake up, send a message via LoRa P2P, and go back to sleep for this fixed period. This setup is necessary because there is no power supply at the specified location, so the controller needs to be battery-operated for an extended time.

My problem is that the RTC is exclusively reserved for the LoRa function, so I can either put the microcontroller to sleep every 10 seconds without using LoRa or send LoRa messages. When I implement both in the program, the microcontroller goes to sleep, wakes up after the defined period, and then does nothing further — no LoRa message, no returning to sleep for the set duration.

I have already tried initializing the RTC-Clock in two different configurations, but neither was successful.

Can anyone advise me on how to solve this problem? Is it even possible to achieve this with the RTC-Clock, or are there other ways to address my requirements?

[ALABSTM]

Hi @Leinad1514,

According to page 241 of the reference manual RM0453, rev. 6, once the STOP2 mode entered, both the RTC and the sub-GHz radio can remain active optionally.

For the RTC, for instance, table 212 at page 1007 indicates that its clock source must be either the LSI or the LSE clock. The same goes for the sub-GHz radio, in the sense that there must certainly be some conditions related to the clock source or another configuration.

Would you mind checking whether the configurations you are using fulfill these conditions?

With regards,

[Leinad1514]

Here my ClockConfig and RTCConfig. For the RTC I have the LSE Clock.

[Leinad1514]

Unfortunately my problem still persists. Do you need any further information? Or do you already have an idea what it could be? @ALABSTM