Install the software¶

Software installation will come with some waiting time — during these times it is possible to assemble hardware not directly connected to the Raspberry Pi.

Install Raspberry Pi OS¶

Download the Raspberry Pi Imager to the extra computer. (See their guide on how to use the installer, if need be.)

Connect the micro SD card to the extra computer.

Run the Raspberry Pi Imager to start the installation process.

Choose "Raspberry Pi 5" as the device.

If you have the optional screen and keyboard for the Raspberry Pi, choose "Raspberry Pi OS (64-bit)" for the OS. Otherwise choose "Raspberry Pi OS Lite (64-bit)".

Choose the connected micro SD card as the storage.

Customize your Raspberry Pi OS as desired, making sure to:

• choose a hostname for the Raspberry Pi (for example "plant-controller")
• choose your localization
• set a username and password
• input your LAN's Wi-Fi credentials (if you are not using a wired connection)
• enable SSH connectivity, if you DON'T have a screen and keyboard for the Raspberry Pi

Finally, set imager options and start writing the OS to the micro SD card. This will erase all things previously stored on the micro SD card before writing the OS and will take a couple of minutes.

When it is done, eject the micro SD card (if it hasn't already been ejected), disconnect it from the computer, and insert it into the Raspberry Pi.

Boot up the Raspberry Pi (connecting the screen and keyboard to it beforehand if available).

If you installed the Raspberry Pi OS with a desktop environment and have a screen and keyboard connected to it, put away the extra computer; it won't be needed for the rest of this guide. Then, open a terminal.

If you installed the Raspberry Pi OS Lite you'll have to connect to the Raspberry Pi over SSH from the extra computer. In the future, when you are instructed to open a new terminal, do it by SSH'ing in from the extra computer in a new terminal.

From the terminal, ensure that the Raspberry Pi is updated by running:

sudo apt-get update -y && sudo apt-get upgrade -y

When everything is updated, continue to the next step.

Install the database¶

The controller uses InfluxDB 3.0 or later to store measurements and watering events.

echo "kernel=kernel8.img" | sudo tee -a /boot/firmware/config.txt
sudo shutdown -r now

Install InfluxDB 3:

curl -O https://www.influxdata.com/d/install_influxdb3.sh \
&& sh install_influxdb3.sh

Choose the local install, and decline when the install script asks whether to start the server at the end. Then start the server yourself:

influxdb3 serve --node-id node0

With the server running, open a new terminal (or SSH session) and create the admin token:

influxdb3 create token --admin

Note the token down — it is referred to as <ADMIN_TOKEN> below, and is needed in the controller's config file. Then create the database for the controller:

influxdb3 create database --token <ADMIN_TOKEN> --retention-period 7d plant-controller

Here the retention period is set to 7 days to avoid gumming up the controller's persistent storage, and the database name to plant-controller, which is the default in the config file. Both can be changed freely, as long as the config file is updated accordingly.

Start InfluxDB automatically¶

To ensure the database starts automatically, create a systemd service:

sudo tee /etc/systemd/system/influxdb3.service > /dev/null << 'EOF'
[Unit]
Description=InfluxDB 3
After=network.target

[Service]
ExecStart=/usr/local/bin/influxdb3 serve --node-id node0
Restart=on-failure

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl daemon-reload
sudo systemctl enable --now influxdb3

Install the controller software¶

First, get the source code onto the Raspberry Pi, either by cloning it from GitHub or by SCP'ing it over from the extra computer:

git clone https://github.com/DisasterlyDisco/plant-controller.git

In the following, <src> refers to the full path of the cloned repository.

Install pip and venv support:

sudo apt-get install -y python3-pip python3-venv python3-setuptools

Create a virtual environment (here in the home directory) and activate it:

cd ~
python -m venv .venv --system-site-packages
source .venv/bin/activate

Install Adafruit Blinka¶

Adafruit Blinka provides the Python API for the Raspberry Pi's GPIO header, which the controller uses for I2C communication with the Adafruit sensor modules. It cannot simply be installed with pip, as it needs to configure the machine itself — Adafruit supplies a convenience script:

cd ~
pip install --upgrade adafruit-python-shell
wget https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/raspi-blinka.py
sudo -E env PATH=$PATH python3 raspi-blinka.py

Install remaining Python dependencies¶

With Blinka installed, install the rest of the Python requirements as normal:

cd <src>/pt/controller_3
pip install -r requirements.txt

Configure the controller