b-parasite b-parasite is an open source soil moisture and ambient temperature/humidity/light sensor. Features Capacitive Soil moisture sensor - see this blog post , this Twitter thread , and this post for nice resources on how they work Air temperature and humidity sensor using a Sensirion's SHTC3 Light sensor using an ALS-PT19 phototransistor Powered by a common CR2032 coin cell, potentially for over two years Support for nRF52840 and nRF52833 modules Open hardware and open source design Software This repository also hosts a few different firmware samples for b-parasite. Sample Description Extra Documentation samples/ble This is the most battle-tested and useful firmware. It periodically reads all sensors and broadcast them via Bluetooth Low Energy (BLE). It works with Home Assistant + BTHome out of the box. Docs samples/zigbee An experimental/educational/exploratory basic Zigbee sample built on nRF Connect + ZBOSS . It integrates with Home Assistant via ZHA or Zigbee2MQTT . Docs samples/blinky The classic "Hello, world" - samples/soil_read_loop Reads the soil moisture sensor on a loop. Useful for experimenting and calibrating the sensor. - samples/input Handles button presses. Useful for power profiling GPIO interrupts and testing debouncing for push switches on boards that have them . - Documentation Information about how to order, assemble, build the samples, protect the sensor and flash the firmware is on the Wiki . Repository Organization code/nrf-connect/ - Common library and samples, built with Nordic's nRF Connect SDK . kicad/ - KiCad schematic, layout and fabrication files for the printed circuit board (PCB) data/ - data for testing and sensor calibration bridge/ - an ESPHome -based BLE-MQTT bridge case/ - a 3D printable case Case We have three different 3D-printable cases: Original snap-on case - case/Top.stl , case/Bottom.stl High airflow - case/b_parasite_case_high_airflow.stl Mushroom-style - available on Printables Accessories Designs and hardware to help you, when building your own: Desk holder for b-parasites Printables License The hardware and associated design files are released under the Creative Commons CC BY-SA 4.0 license . The code is released under the MIT license .
