# STEMMA capacitive soil moisture sensor (I2C)

Manufacturer: Adafruit  |  MPN: 4026  |  Category: soil-sensor
Canonical: https://partsgraph.ai/catalog/parts/adafruit-stemma-soil
Image: https://partsgraph.ai/catalog/img/adafruit-stemma-soil.jpg (photo: Adafruit, CC BY-SA; sha256 e9bcbbdca331)

## Attributes (each with provenance)

- **Interface**: I2C
  - source: https://www.adafruit.com/product/4026
  - quote: "Adafruit STEMMA Soil Sensor - I2C Capacitive Moisture Sensor [JST PH 2mm] : Adafruit Industri"
- **Sensing**: Capacitive
  - source: https://www.adafruit.com/product/4026
  - quote: "Adafruit STEMMA Soil Sensor - I2C Capacitive Moisture Sensor [JST PH 2mm] : Adafruit Industries, Unique"
- **Moisture reading span**: 200 (very dry) to 2000 (very wet)
  - source: https://www.adafruit.com/product/4026
  - quote: "MD10 chip, which will give you a reading ranging from about 200 (very dry) to 2000 (very wet). As a bonus, we also give you the ambient temperature from"
- **Temperature accuracy**: + or - 2 degrees Celsius
  - source: https://www.adafruit.com/product/4026
  - quote: "the microcontroller, it's not high precision, maybe good to + or - 2 degrees Celsius. To make it so you can use the sensor with just about any m"
- **Supply voltage**: 3-5V
  - source: https://www.adafruit.com/product/4026
  - quote: "tocked) to your microcontroller or single board computer to 3-5V power, Ground, I2C SDA and I2C SCL and then run our Arduino"
- **Onboard microcontroller**: ATSAMD10
  - source: https://www.adafruit.com/product/4026
  - quote: "built in capacitive touch measurement system built into the ATSAMD10 chip, which will give you a reading ranging from about 200"
- **Dimensions**: 76.2mm x 14.0mm x 7.0mm
  - source: https://www.adafruit.com/product/4026
  - quote: "ay need to extend delays between reads. Product Dimensions: 76.2mm x 14.0mm x 7.0mm / 3.0" x 0.6" x 0.3" Product Weight: 4.0g / 0.1oz Learn Pri"
- **Weight**: 4.0 g
  - source: https://www.adafruit.com/product/4026
  - quote: "6.2mm x 14.0mm x 7.0mm / 3.0" x 0.6" x 0.3" Product Weight: 4.0g / 0.1oz Learn Primary Guide: Adafruit STEMMA Soil Sensor -"
- **Connector**: JST PH 2mm
  - source: https://www.adafruit.com/product/4026
  - quote: "afruit STEMMA Soil Sensor - I2C Capacitive Moisture Sensor [JST PH 2mm] : Adafruit Industries, Unique & fun DIY electronics and ki"
- **Interface signals**: power, Ground, I2C SDA and I2C SCL
  - source: https://www.adafruit.com/product/4026
  - quote: "d) to your microcontroller or single board computer to 3-5V power, Ground, I2C SDA and I2C SCL and then run our Arduino or CircuitPython code to read the"
- **Ambient temperature sensing**: yes
  - source: https://www.adafruit.com/product/4026
  - quote: "a bonus, we also give you the ambient temperature from the internal temperature sensor on the microcontroller, it's not high precision, maybe good"
- **Probe count**: one probe
  - source: https://www.adafruit.com/product/4026
  - quote: "a capacitive measurement. Capacitive measurements use only one probe, don't have any exposed metal, and don't introduce any DC c"
- **Exposed metal**: no
  - source: https://www.adafruit.com/product/4026
  - quote: "ve measurement. Capacitive measurements use only one probe, don't have any exposed metal, and don't introduce any DC currents into your plants. We u"
- **Introduces DC current into soil**: no
  - source: https://www.adafruit.com/product/4026
  - quote: "ments use only one probe, don't have any exposed metal, and don't introduce any DC currents into your plants. We use the built in capacitive touch meas"
- **Soldering required**: no
  - source: https://www.adafruit.com/product/4026
  - quote: "on code to read the temperature and capacitive measurement. No soldering required! Please note: This is just the sensor, you'll also need a J"
- **Seeed Grove cable compatible**: yes
  - source: https://www.adafruit.com/product/4026
  - quote: "ns , female header pins , and a JST-JST cable . You can use Seeed Grove cables and boards to connect - the Grove cable is a little differe"
- **Cable included**: no
  - source: https://www.adafruit.com/product/4026
  - quote: "ve measurement. No soldering required! Please note: This is just the sensor, you'll also need a JST 4-PH cable to go along for plugging"

## Vendors

- Adafruit: https://www.adafruit.com/product/4026 (~USD 7.5, indicative as of 2026-08-18)
- Pimoroni: https://shop.pimoroni.com/products/adafruit-stemma-soil-sensor-i2c-capacitive-moisture-sensor (~GBP 7.2, indicative as of 2026-08-18)

## Datasheets

- Soil sensor product page: https://www.adafruit.com/product/4026

Used in builds: plant-waterer (roles: moisture-sensor)

Machine feed of the whole catalogue: https://partsgraph.ai/catalog/feed.json