low-power operation optimization #5
Description
Currently, the ESP32 is always in active mode. Thus, power consumption is unreasonably high for a battery-powered system.
- During sending periods (reading sensor values and sending them via LoRaWAN), the ESP32's modems can be turned of. Namely, the Wifi and Bluetooth modules.
- During sending breaks, not activity is necessary. Thus, the whole board can be send to a sleep mode. Preferably, session information is to be retained to avoid unnecessary rejoining.
Especially the second case needs further attention. Either, the ESP32 can start deep sleep mode. This would enable the node to store session information. When starting hibernation sleep mode, the power consumption is even lower but session information would be lost.
It is to be checked, which appraoch is more energy efficient: Either higher-consumption but less time in an active state or lower-consumption but more tiem in an active state.