We are working with SensorTile (STM32L476). To reduce power consumption, we are using the standby mode with sram2 retention. Our intention is to configure BlueNRG-MS (with advertising enabled), enter standby mode and wait for a user connection through smartphone. The problem is that after wake-up, the SPI/BlueNRG-MS is reconfigured and we can't establish the connection.
We are trying to use this sequence:
- initilize the ble stack/SPI, storing in SRAM2 all the varibles we think that needs retention;
- enter advertising;
- enter standby mode with SRAM2 retendion;
- wait connection event (ble interrupt);
- reconfigure SPI; (for me our problem is here)
- trying to create connection after interrupt;
What is the best way to do this? What do we need to store in SRAM2 before standby? What do we need to reconfigure after wake-up?