2021-08-06 12:16 PM
I am trying to write FW for the WB55 which starts a BLE server on powerup ( so far so good)
then after BLE connected to and a characteristic has been written and BLE disconnected I want to be able to enter standby mode
Upon an RTC wakeup the FW will see its not a power and NOT start the BLE stack, but still start the scheduler for data acquisition tasks.
Can you point me to examples or documentation?
2021-08-19 10:06 AM
I assume BLE disconnect means no active connection anymore. In that case the RF block and its related RF stack running on the M0+ core enter CSTOP mode at the end of RF activity and will remain in that state till a new command is issued by the application running on the M4 core.
The M4 core can enter CSTOP mode when it completes its task, leading the system to be STOPx or STANDBY mode depending on the LPMS bit of the PWR_CR1 (Low-power mode selection for CPU1) and/or PWR_C2CR1 (allowed low-power mode from CPU2) registers.
To be able to retain data from current state, SRAM2a content needs to be retained via the PWR_CR3.RRS bit.
I need to check whether one of our examples is using this standby mode.