Gerry from the german sailing forum has built a keel sensor to show the depth of a recoverable keel. In addition to the keel depth, the heeling is also displayed. The measurement data can be displayed via WLAN, for example in a mobile phone browser. The following components were used for the keel sensor:
- ESP32 NodeMCU (WLAN-enabled microcontroller)
- MB1043 HRLV-MaxSonar-EZ4 (ultrasonic sensor with narrow beam)
- MMA8452 (3-axis gyro sensor for inclination display )
- D24V10F5 (voltage regulator)
The whole thing can be set up quite easily on a breadboard. Circuit diagram tells you more about the wiring.