STM32WB06 low-power issue with BLE auto connection

[xxyyhhmm]

Hi, I'm having some issues with the STM32WB06 when trying to achieve low power consumption. I hope someone can help me solve these problems.

Issue 1: After initializing the Bluetooth protocol stack and enabling automatic connection establishment, it causes the device to fail to enter the low power state (BLE wake-up has been disabled). Is this a normal phenomenon? If not, what are the solutions?

Issue 2: Before entering the low power mode, disabling automatic connection establishment allows the device to enter the low power mode normally. However, after waking up, attempting to re-enable automatic connection establishment fails (aci_gap_start_procedure(GAP_AUTO_CONNECTION_ESTABLISHMENT_PROC, LE_1M_PHY_BIT, 0, 0)). What is the solution for this problem?

 

I look forward to your replies. Thank you very much!

[Imen.D]

Hello ​@xxyyhhmm and welcome to the Community,

Thanks for your patience.

I consulted our Wireless team, and they answered the following:

Autoconnection establishment procedure consists in scanning for devices. The ability to enter low power states depends on the duty cycle. If the duty cycle is near 100 %, the device cannot enter deepstop mode. The device can use deepstop mode between scan windows only if there is enough time (i.e. more than 2-3 ms).

Regarding the issue with the restart of the procedure, we need to know the complete sequence of commands.