Today I measured the power consumption of the bouy setup. I added a pin-header to the board which I can use to cut the BATT+ track and place the PKKII from nordic in between to measure the current consumption.

The implementation is as follows: 

1. Device boots
2. Measures Pressure and temperature
3. Connects to ESPNow (the Station is setup as Broadcast device and the Bouy broadcasts its data)
4. A time is calculated to be set as alarm to the RTC 
5. Wake on GPIO setup
6. Go to deep sleep 

Once the Alarm is triggered the RTC pulls its event pin low which triggers the ESP32 to wakeup and run the code again. The same happens on the Station.

This whole cycle takes ~600ms and consumes an average of 65mA. While sleeping the device draws ~350µA

So far - so good! 

This can still be improved! The LED is currently on a brightness of 100% for the whole time (for debugging and visibility) and the Pressure Sensor is in continous measurement mode it can be changed to manually measure only in the active cycle. I am using toit as a code-base and there is currently also some time improvements which could lower the cycle time.