We have been covering and reviewing open source ANAVI hardware boards for several years now, either standalone boards based on ESP8266 or expansion boards for Raspberry Pi.
The ANAVI Gardening uHAT is Leon Anavi’s latest board. This is a micro HAT designed for Raspberry Pi Zero to Raspberry Pi 4 SBCs that offers interfaces for soil sensors and other environmental sensors to measure soil moisture, atmospheric pressure and humidity, temperature with a waterproof sensor and light intensity for gardening applications.
Key features and specifications of ANAVI Gardening uHAT:
- Compatibility – Any Raspberry Pi board with a 40 pin GPIO header
- Storage – EEPROM for uHAT compliance
- 2 3-pin connectors for capacitive soil moisture sensors connected to the Microchip MCP3002 ADC chip
- 3-pin single-wire terminal block for a waterproof temperature sensor
- 2 4-pin I²C connectors for additional sensors
- 10 heads with GPIO pins to control irrigation systems and peripherals
- Miscellaneous – 2x user LEDs, UART pins for serial communication
- Dimensions – uHAT Mechanical Specifications with a valid EEPROM ID
- OSHWA Certification – BG000079
By the way, uHAT (Micro HAT) used to be called pHAT (Partial HAT), but the Raspberry Pi Foundation changed that in 2018.
As with other ANAVI designs, the Gardening uHAT is fully open source hardware with KiCAD schematics, PCB layout, BoM and Gerber files, plus software and documentation all available on Github. The project has also just received certification from the Open Source Hardware Association with UID BG000079.
Code samples are available in C and Python and include support for the DS18B20 waterproof temperature sensor, HTU21D sensor for temperature and humidity, BH1750 sensor for light, BMP180 sensor for barometric pressure, and capacitive soil moisture sensors.
Other analog, I2C and one-wire sensors may also be supported, but you will need to handle the programming yourself. The same goes if you want to automate gardening, for example watering plants, with your Raspberry Pi.
The board is only offered as a part in kits with the Starter Kit comprising the uHAT and two capacitive soil moisture sensors, the Advanced kit the addition of light, temperature and humidity sensors, and the Developer kit providing additional functionality with a waterproof temperature sensor and USB to serial debugging cable.
You will find the kits between $ 28 and $ 48 on Crowd Supply with free shipping in the US and $ 12 to the rest of the world. Deliveries are expected to start around mid-February 2022.
Jean-Luc started CNX Software in 2010 part-time, before stepping down as head of software engineering and starting writing daily news and reviews full-time later in 2011.