I think, I didn’t explained well my project. Let say, I want to record temperature. Each hour, the board record a temperature and store it internally (in the QSPI Flash memory). One or two times a year, I will visit the logger on field. I will transfer data from the logger to a smartphone. So most of the time, the logger don’t transmit data. It is just waiting for a connexion. Once the connexion is established, I don’t care too much on power consumption (although it should not drain the battery in one minute). So, how can I set some kind of “wait for connexion” with a low power consumption?