Monitor moisture levels rather than distance

[michaeljolley]

Current Situation

Currently the code is using a Grove ultrasonic range sensor to detect distance in centimeters. It sends that value as moistureLevel. We need to update this to actually use a moisture sensor and send actual moisture levels to Mother Bird.

@bsatrom introduced me to the Adafruit STEMMA Soil Sensor - I2C Capacitive Moisture Sensor and I've got 5 on the way here.

Goals

• [ ] In Baby Bird, remove references/code related to the ultrasonic range sensor and replace with references/code to communicate with the Adafruit Sensor
• [ ] Return the true moisture level in the payload to Mother Bird

[michaeljolley]

Working on this one during the stream Sunday, May 26th.

Sensors arrived today.