BTHome water meter

An ESP-IDF project which counts pulses in ULP unit and sends data encoded in the BTHome format over BLE.

Pulses are counted in Ultra Low Power coprocessor in deep-sleep mode with consumption about 0.00016A. When counter reach 5 pulses, it wakes up main ESP unit, add recently counted pulses to NVS memory and start broadcasting BLE signal (in BTHome standard), after that, it goes deep-sleep again.

Instructions

1. Set up platform.io project (you can use VSCode with platform.io extension)
2. Run build and upload to your board
3. Connect GPIO 4 and GND with your pulse generator

• port GPIO4 is set up as pull-up, so you can connect any pulse generator with high-impedance state

4. New BTHome device should appear in home-assistant automatically

References

1. BTHome Weather Station
2. ULP Pulse Counting Example
3. BTHome

Improvements

1. Battery monitoring
2. Solve how to setup initial state