🌱💧 An open source DIY soil moisture sensor
7b4e64cec7
This is a "tricky" workaround due to the lack of physical buttons: We can distinguish between the two "power up" modes: - Power on: when the device receives power for the first time. Example: swapping batteries, prroviding external power. This _DOES NOT_ reset the pairing info. - Reset pin: when the device is manually reset (by shorting the RESET pin to GND), or when a new firmware is flashed. This _RESETS_ the pairing info. |
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| .devcontainer | ||
| .github | ||
| bridge | ||
| case | ||
| code | ||
| data/adc-moisture-estimation | ||
| experimental/rotisserie | ||
| flashing/pyocd | ||
| img | ||
| kicad | ||
| .gitignore | ||
| README.md | ||
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 out of the box. | Docs |
| samples/blinky | The classic "Hello, world" | - |
| samples/soil_read_loop | Read the soil moisture sensor on a loop. Useful for experimenting and calibrating the sensor. | - |
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
A 3D printable case model can be found in case/.
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.