BLE Remote using STM32WB55

[fo]

Hello,

I'm working on a BLE Key Fob with 4 buttons operating on a CR2032 coin-cell battery. The goal is that the device sends a "key pressed" data with the status of all the buttons and the battery voltage a short time of period (a couple of seconds), then the device enters in to STOP2 mode, and only wakes up when a key is pressed. The data pack is formatted in BT Home format.

I used the BLE Beacon example. Currently I've managed to read the button states and the supply voltage level, make a BT Home packet, and advertise the data. However, I can't get the MCU to switch to STOP2 mode. With the CFG_LPM_SUPPORTED enabled the current consumption is approx. 100µA with a beacon interval of 1s. There are questions about stopping the advertisement, but there is not a clear answer that I could use in my project. What is the correct approach in order to achieve my requirements?

Thanks in advance.

Best Regards,
Fatih

[STTwo-32]

Hello @fo 

I recommend having a look at BLE_HeartRate example.

This example uses LP manager which allows you to easily manage different LP modes.

Also, you should have a look at the AN5289.

More details are available on those two discussions:

1. Solved: How to enter stop2 mode in stm32wb, when the Ble s... - STMicroelectronics Community
2. How to put the STM32WB55 in STOP2 mode - STMicroelectronics Community

Best Regards.

STTwo-32