Product description
Adafruit STEMMA Soil Sensor is a capacitive soil moisture sensor with an I2C interface for measuring soil moisture without the corrosion problems commonly found in resistive sensors. The design uses a capacitive measurement method without exposed metal surfaces in the soil section, providing more stable readings over time and reducing the need for recalibration.
The sensor is based on the ATSAMD10 and uses the built-in capacitive sensing hardware to measure soil moisture levels. In addition to moisture sensing, it can also report ambient temperature using the internal temperature sensor. The sensor communicates via I2C and connects using a 4-pin JST PH connector, making it compatible with multiple microcontroller platforms without soldering.
The moisture value is returned as a capacitive measurement value rather than a calibrated VWC value (Volumetric Water Content). Typical readings are around 200 in very dry soil and up to approximately 2000 in very wet soil.
Specifications:
- Product: Adafruit STEMMA Soil Sensor – I2C Capacitive Moisture Sensor
- Sensor principle: Capacitive soil moisture sensing
- Communication: I2C
- I2C address: 0x36
- Moisture measurement range: Approximately 200 to 2000 (relative value)
- Temperature measurement: Built-in temperature sensor in ATSAMD10
- Supply voltage: 3-5VDC
- Connection: JST PH 2mm 4-pin (cable not included)
- I2C pull-up resistors: 10kΩ on SDA and SCL
- Microcontroller: ATSAMD10
- Compatibility: Arduino, CircuitPython, Raspberry Pi, and other I2C-compatible systems
