🌱💧 An open source DIY soil moisture sensor

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rbaron 1983f31af9 Store calibration polynomial in devicetree This will enable us to transparently use different calibration for different board revisions. The 2.0.0 revision changes the sensing circuitry and will need its own coeffs. In this commit, both models are run in parallel for debugging.		2023-03-19 15:06:39 +01:00
.devcontainer	Update containers to use SDK 2.2.0	2023-01-22 19:03:34 -05:00
.github	Update containers to use SDK 2.2.0	2023-01-22 19:03:34 -05:00
bridge	Defaults to BLE protocol version 1	2022-03-15 08:52:37 +01:00
case	high airflow case design stl and 3mf files	2022-10-10 13:16:10 -07:00
code	Store calibration polynomial in devicetree	2023-03-19 15:06:39 +01:00
data/adc-moisture-estimation	Sets transmitting power to +8dB	2021-03-31 18:37:50 +02:00
experimental/rotisserie	Adds missing base.stl to experimental/rotisserie	2022-11-08 19:19:08 +01:00
flashing/pyocd	Fixed typo in readme and changed meaning of the sentence to better reflect the actual situation.	2022-10-23 19:00:57 +02:00
img	Adds img/wiki/swdpins.jpg	2021-08-08 15:31:03 +02:00
kicad	Fix stale silkscreen 1.2.0 -> 2.0.0	2023-03-19 15:06:39 +01:00
.gitignore	Adds a simple battery monitoring circuit and analog to digital measuring.	2021-02-14 10:59:18 +01:00
kitspace.yaml	Add gerbers field to kitspace.yaml	2023-01-30 22:42:11 +00:00
README.md	Better docs	2022-12-24 10:06:35 +01:00

b-parasite

PCB front and back photo

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

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/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	Read the soil moisture sensor on a loop. Useful for experimenting and calibrating the sensor.	-

Information about how to order, assemble, build the samples, protect the sensor and flash the firmware is on the Wiki.

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

b-parasite stuck into a small plant vase

A 3D printable case model can be found in case/.

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.