Open source smart gardening done easy, with Raspberry Pi
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This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://www.creativecommons.org/licenses/by-sa/3.0/.
ANAVI Gardening uHAT hardware design is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
The software examples are released under MIT and the rest of the software is available under GPLv3.
It is possible that the pictures in this manual differ from the latest revision of the board.
The product described in this document is subject to continuous development and improvements. All particulars of the product and its use contained in this document are given by Anavi in good faith. However all warranties implied or expressed including but not limited to implied warranties of merchantability or fitness for purpose are excluded. This document is intended only to assist the reader in the use of the product. Anavi shall not be liable for any loss or damage arising from the use of any information in this document or any error or omission in such information or any incorrect use of the product.
This evaluation board/kit is intended for use for engineering development, demonstration, or evaluation purposes only and is not considered by Anavi to be a finished end-product fit for general consumer use. People handling the product must have electronics training and observe good engineering practice standards. As such, the goods being provided are not intended to be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product safety and environmental measures typically found in end products that incorporate such semiconductor components or circuit boards.
There is no warranty for the design materials and the components used to create ANAVI Gardening uHAT. They are considered suitable only for ANAVI Gardening uHAT.
ANAVI Gardening uHAT is a low-cost, open source Raspberry Pi add-on board that helps you develop smart solutions for monitoring and growing plants.
ANAVI Gardening uHAT supports multiple sensors for soil moisture, temperature, humidity, barometric pressure, and light. Getting started is easy: just plug it into a Raspberry Pi with your bare hands and follow the instructions in the user manual. No soldering is necessary, and no tools are required.
ANAVI Gardening uHAT Raspberry Pi HAT includes:
- Slots for up to two capacitive soil moisture sensors
- Slot for a waterproof temperature sensor
- Slots for up to two plug-and-play I²C sensors
- UART pins for serial communication
- GPIO pins for controlling irrigation systems and peripherals
- Green and red indication LEDs
- Microchip MCP3002 analog-to-digital converter (ADC)
- Follows uHAT mechanical specification with a valid ID EEPROM
- Excellent software support, documentation, and open source examples
ANAVI Gardening uHAT is compatible with the following Raspberry Pi versions and models:
- Raspberry Pi 400
- Raspberry Pi 4 Model B
- Raspberry Pi 3 Model B
- Raspberry Pi 2 Model B
- Raspberry Pi Zero
- Raspberry Pi Zero W
- Raspberry Pi Zero 2 W
- Raspberry Pi Model B+
- Raspberry Pi Model A+
ANAVI Gardening uHAT is NOT compatible with the earlier 26-pin models of Raspberry Pi 1 Model B & A's.
ANAVI Gardening uHAT is a Raspberry Pi HAT suitable for existing Raspberry Pi customers interested in home automation, software development and Internet of Things. The board is appropriate for embedded programming enthusiasts, GNU/Linux gadget fans, students as well as web and/or mobile app developers.
Revision 1.3 of ANAVI Gardening uHAT was used while writing this document. It is possible that it is outdated so it is always recommended to check the latest sources from the GitHub page of the board.
- This product shall only be connected to a compatible Raspberry Pi.
- Do not expose this product to water or moisture, and do not place it on a conductive surface whilst in operation.
- Do not expose this product to heat from any source; it is designed for reliable operation at normal room temperatures.
- Take care while handling this product to avoid mechanical or electrical damage to the printed circuit board and connectors.
- Avoid handling this product while it is powered. Only handle by the edges to minimize the risk of electrostatic discharge damage.
ANAVI Gardening uHAT is shipped in a protective antistatic bag. The HAT as well as the Raspberry Pi must NOT be exposed to high electrostatic potentials. A grounding strap or similar protective device should be worn when handling the board. Avoid touching the component pins or any other metallic element.
In order to setup ANAVI Gardening uHAT the following items are required:
- Compatible Raspberry Pi
- microSD card with compatible image
- USB power supply
Additionally you may attach USB mouse, keyboard, HDMI monitor or addition peripheral devices to your Raspberry Pi. It is recommended to use 2.5A (2500mA) power supply.
ANAVI Gardening uHAT for Raspberry Pi features an MCP3002 analog-to-digital converter (ADC), dual connectors for capacitive soil moisture sensors, and supports up to 2 I2C sensors, one 1-wire sensor, and a UART header for added versatility.
The officially supported I2C sensor modules by ANAVI Gardening uHAT are:
- Temperature and barometric pressure (BMP180)
- Temperature and humidity (HTU21)
- Light (BH1750)
You may also attach any other I2C sensors but you will have to take care of their software integration.
BMP180 is I2C sensor capable of measuring both temperature and barometric pressure.
Using 4 Dupont jumper wires connect BMP180 to one of the 3 I2C slots on ANAVI Gardening uHAT as follows:
| BMP180 | ANAVI Gardening uHAT |
|---|---|
| VIN | 3.3V |
| GND | GND |
| SCL | SCL |
| SDA | SDA |
HTU21 (SHT21) is I2C sensor capable of measuring both humidity and temperature.
Using 4 Dupont jumper wires connect HTU21 to one of the 3 I2C slots on ANAVI Gardening uHAT as follows:
| HTU21 | ANAVI Gardening uHAT |
|---|---|
| VIN | 3.3V |
| GND | GND |
| SCL | SCL |
| SDA | SDA |
BH1750 is a light sensor.
Using 4 Dupont jumper wires connect BH1750 to one of the 3 I2C slots on ANAVI Gardening uHAT as follows:
| BH1750 | ANAVI Gardening uHAT |
|---|---|
| VCC | 3.3V |
| GND | GND |
| SCL | SCL |
| SDA | SDA |
You can assemble ANAVI Gardening uHAT and mount it on your Raspberry Pi with your bare hands following the steps below:
- Ensure that you Raspberry Pi is compatible with ANAVI Gardening uHAT.
- Power off your Raspberry Pi.
- Gently mount ANAVI Gardening uHAT on the 40 pin header of your Raspberry Pi.
- Add sensors to your ANAVI Gardening uHAT.
- Optionally, you may also mount two or four brass M2.5 standoffs to keep your Pi HAT snug on your Raspberry Pi while also keeping the two boards separated.
- That's all, now you are ready to go!
ANAVI Gardening uHAT is Raspberry Pi HAT therefore it is powered through Raspberry Pi. It is recommended to use the official Raspberry Pi Power Supply or another 2.5A USB power supply from reputable retailer.
In order to work correctly, ANAVI Gardening uHAT requires an up-to-date kernel, I2C to be enabled, and a few libraries to get started. After booting microSD card with Raspberry Pi OS (previously known as Raspbian), open a terminal and follow the steps below:
- Ensure your APT package list is up-to-date:
sudo apt update
- Install additional applications, libraries and other tools needed by ANAVI Gardening uHAT
sudo apt install -y git i2c-tools vim
Follow the steps below to enable I2C which is required by the sensors for ANAVI Gardening uHAT.
- Open a terminal or login remotely via SSH to your Raspberry Pi and type in the following command:
sudo raspi-config
-
Select Interfacing Options > I2C and enable it.
-
Reboot the board.
Follow the steps below to enable SPI which is required by the capacitive soil moisture sensors for ANAVI Gardening uHAT.
- Open a terminal or login remotely via SSH to your Raspberry Pi and type in the following command:
sudo raspi-config
-
Select Interfacing Options > SPI and enable it.
-
Reboot the board.
Follow the steps below to enable 1-Wire which is required by the waterproof temperature sensor for ANAVI Gardening uHAT.
- Open a terminal or login remotely via SSH to your Raspberry Pi and type in the following command:
sudo raspi-config
-
Select Interfacing Options > 1-Wire and enable it.
-
Reboot the board.
Follow the steps below to enable serial debugging through USB to serial cable:
- Open a terminal or login remotely via SSH to your Raspberry Pi and type in the following command:
sudo raspi-config
-
Select Interfacing Options > Serial and enable it.
-
Reboot the board.
-
Plug the USB to serial cable and connect your Raspberry Pi to your PC. The RX line of the cable should go to TX line of UART on ANAVI Gardening uHAT. The TX line of the cable should go to the RX line of UART on ANAVI Gardening uHAT. The GND wire should go to the GND line of UART on ANAVI Gardening uHAT.
-
Type in the following command on your computer if you are using GNU/Linux distribution to access ANAVI Gardening uHAT. Alternatively if your OS is Microsoft Windows use putty.
The recommended USB to UART serial modules for ANAVI Gardening uHAT are any with CP2102 or Olimex USB-Serial-Cable-F. All developer kits include CP2102 which out of the box on GNU/Linux distributions. Drivers for MS Windows and Mac OS X are available at silabs.com.
Sample applications written in Python and the C programming language are provided for ANAVI Gardening uHAT under MIT license in GitHub. All examples have been tested on Raspberry Pi OS (previously known as Raspbian).
Open a terminal and execute the follow the steps by step instructions to install all dependencies and to get the source code:
- Install dependencies:
sudo apt update
sudo apt install -y git vim libi2c-dev python3 python3-dev python3-pip python3-smbus i2c-tools
- Download the examples for ANAVI Gardening uHAT
cd ~
git clone https://github.com/AnaviTechnology/anavi-examples.git
cd anavi-examples
It is mandatory to enable SPI, 1-Wire and I2C to use all of the sensors supported by ANAVI Gardening uHAT.
Capacitive Soil Moisture Sensor v1.2 and v2.0 measures the volumetric content of water inside the soil and retrieves the moisture level by capacitive sensing rather than resistive sensing like other sensors. The benefit of using a capacitive soil moisture sensor is the lack of corrosion and longer lifespan.
nlike Raspberry Pi Pico, the recently released microcontroller, all versions and models of the Raspberry Pi single-board computers do not include an analog-to-digital converter (ADC). ANAVI Gardening uHAT adds Microchip MCP3002 to your Raspberry Pi.
Microchip MCP3002 is a 10-bit resolution, dual channel ADC with SPI hardware bus. It can be connected to any Raspberry Pi single board computer version and model, including Raspberry Pi 4 and Raspberry Pi 0. However, this tutorial is not for Raspberry Pi Pico microcontroller. For more details about the wiring of Microchip MCP3002 a Raspberry Pi single-board computer have a look at this tutorial.
Make sure SPI has been enabled. Python3 script for reading data from a couple of capacitive soil moisture sensors through Microchip MCP3002 ADC is available at the anavi-examples repository in GitHub. The script relies on popular Python libraries spidev and RPi.GPIO. Open a terminal and run the following commands torun the script from anavi-examples:
cd ~/anavi-examples/anavi-gardening-uhat/soil-moistore-sensors/python/
python3 soil-moistore-sensors.py
Make sure the Raspberry Pi is turned off and attach the waterproof DS18B20 temperature sensor to the dedicated terminal connector on ANAVI Gardening uHAT. The red wire of the sensor is for 3.3V, the black wire is for GND and the yellow wire is for the signal. 1-Wire must have been enabled. Power on the Raspberry Pi and read the temperature values as follows:
cat /sys/bus/w1/devices/*/w1_slave
Follow the steps below to use the BMP180 I2C temperature and barometric pressure sensor with ANAVI Gardening uHAT:
-
Connect BMP180 to any of the I2C slots on ANAVI Gardening uHAT using male to female Duport jumper wire.
-
Type in the following command and verify that the address of the sensor is listed:
sudo i2cdetect -y 1
The address of BMP180 I2C sensor is 77, for example:
pi@raspberrypi:~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- 77
- Run the Python3 script and verify that the output is similar to (the exact values depend on the atmospheric condition):
cd ~/anavi-examples/sensors/BMP180/python/
python3 BMP180.py
For example:
pi@raspberrypi:~ $ cd ~/anavi-examples/sensors/BMP180/python/
pi@raspberrypi:~/anavi-examples/sensors/BMP180/python $ python3 BMP180.py
Temperature: 21.99C
Pressure: 1002hPa
Follow the steps below to use the HTU21D I2C temperature and humidity sensor with ANAVI Gardening uHAT:
-
Connect HTU21D to any of the I2C slots on ANAVI Gardening uHAT using male to female Duport jumper wire.
-
Type in the following command and verify that the address of the sensor is listed:
sudo i2cdetect -y 1
The address of HTU21D I2C sensor is 40, for example:
pi@raspberrypi:~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: 40 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
- Type in the following commands to build and run the sample application that display temperature and humidity:
cd ~/anavi-examples/sensors/HTU21D/c/
make
./HTU21D
- Verify that the output is similar to (the exact values depend on the atmospheric condition):
pi@raspberrypi:~/anavi-examples/sensors/HTU21D/c $ ./HTU21D
HTU21D Sensor Module
22.90C
62.89%rh
- Run the Python3 script and verify that the output is similar to (the exact values depend on the atmospheric condition):
cd ~/anavi-examples/sensors/HTU21D/python/
python3 htu21d.py
For example:
pi@raspberrypi:~ $ cd ~/anavi-examples/sensors/HTU21D/python/
pi@raspberrypi:~/anavi-examples/sensors/HTU21D/python $ python3 htu21d.py
Temperature: 22.77C
Humidity: 63.0%
Follow the steps below to use the BH1750 I2C light sensor with ANAVI Gardening uHAT:
-
Connect BH1750 to any of the I2C slots on ANAVI Gardening uHAT using male to female Dupont jumper wires.
-
Type in the following command and verify that the address of the sensor is listed:
sudo i2cdetect -y 1
The address of BH1750 I2C sensor is 23, for example:
pi@raspberrypi:~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- 23 -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
- Type in the following commands to build and run the sample application that display luminous emittance:
cd ~/anavi-examples/sensors/BH1750/c/
make
./BH1750
- Verify that the output is similar to (the exact values depend on the atmospheric condition):
pi@raspberrypi:~/anavi-examples/sensors/BH1750/c $ ./BH1750
BH1750 Sensor Module
Light: 392 Lux
- Run the Python3 script and verify that the output is similar to (the exact values depend on the atmospheric condition):
cd ~/anavi-examples/sensors/BH1750/python/
python3 bh1750.py
For example:
pi@raspberrypi:~ $ cd ~/anavi-examples/sensors/BH1750/python/
pi@raspberrypi:~/anavi-examples/sensors/BH1750/python $ python3 bh1750.py
Light: 399 Lux
Device Tree (DT) in Linux is a description of the hardware in a system. The DT overlay adds a number of optional elements.
The EEPROM of ANAVI Gardening uHAT contains DT overlay with description of the peripheral devices on the HAT. After adding Anavi to your Raspberry Pi and booting it you should have some new filesystem nodes at /proc/device-tree/hat:
pi@raspberrypi:~ $ ls -l /proc/device-tree/hat/
total 0
-r--r--r-- 1 root root 4 Feb 15 00:27 name
-r--r--r-- 1 root root 20 Feb 15 00:27 product
-r--r--r-- 1 root root 7 Feb 15 00:27 product_id
-r--r--r-- 1 root root 7 Feb 15 00:27 product_ver
-r--r--r-- 1 root root 37 Feb 15 00:27 uuid
-r--r--r-- 1 root root 6 Feb 15 00:27 vendor
The information provided in these filesystem nodes helps you to identify ANAVI Gardening uHAT vendor, version, product name, etc. For example:
pi@raspberrypi:~ $ cat /proc/device-tree/hat/product
ANAVI Gardening uHAT
pi@raspberrypi:~ $ cat /proc/device-tree/hat/vendor
ANAVI
More information about device trees, overlays and parameters are available at the official Raspberry Pi documentation.
The components of ANAVI Gardening uHAT utilize the following pins on Raspberry Pi:
| Component | Pins |
|---|---|
| I2C | 3, 5 |
| EEPROM | 27, 28 |
| MCP3002 | 19, 21, 23, 24 |
| UART | 1, 8, 9, 10 |
| LED D1 | 15 |
| LED D2 | 16 |
The sensors that can be connected to ANAVI Gardening uHAT communicate with a host microcontroller via a communications standard called I2C (Inter-Integrated-Circut). I2C uses two wires, labelled SDA (Serial Data) and SCL (Serial Clock). To function properly, I2C requires a pullup resistor on each of those lines therefore ANAVI Gardening uHAT includes two 4.7kohm resistors labelled as R6 and R7. If for one reason or another you need to disable the I2C pullup resistors remove R6 and R7.
Yes, you can use ANAVI Gardening uHAT with other GNU/Linux distributions and even other operating systems but some porting efforts might be required.
Yes, you can use other I2C sensors with ANAVI Gardening uHAT but you should take care for their drivers and software support.
Yes, you may install popular open source software for home automation on your Raspberry Pi such as Home Assistant or OpenHAB 2 and integrate ANAVI Gardening uHAT.
Yes, the official ANAVI Gardening uHAT software is free and open source. The examples are available under MIT license and the rest is available under GPLv3. Please contact us if you are working on a commercial product and you would like to use the software under alternative commercial license.
| Date | Changes | Modified pages | Author |
|---|---|---|---|
| 08 February 2022 | Initial manual release | All | Leon Anavi |
| 08 May 2022 | Update examples | All | Leon Anavi |
| Revision | Notable changes |
|---|---|
| 1.0 | First version |
| 1.3 | Switched to capacitive soil-moisture sensors |
For more information please visit anavi.technology and our GitHub repositories. If you have any questions or enquiries please contact us through Facebook, Twitter or email.