Thingy:53 Aeroponic Garden

2nd place in Smarter Sustainable World Challenge with Nordic Semiconductor. For details of the project itself see Vertical Self Regulating Soilless Farm

Physical setup

The pot

• Print heater_bottom_n.stl and heater_top_n.stl (n = 1, 2, 3, 4) and glue them together. Insert 12V 5050 fan into place
• Print funnel.stl and insert it into heater glued in previous step
• Print num_layers * 4 layer_quarter.stl and glue them together then stack the layers and place them on top of the heater
• Print num_layers nozzle_frame.stl and num_layers * 4 nozzle_single.stl and glue them together then using straight plastic pipe assemble them starting from funnel's center intlet so that each nozzle_frame is on the level of the pot of given layer
• Print nozzle_frame_end.stl and insert it at the top of previously created piping
• Print top_hat.stl and insert it at the top of vertical pot then insert Thingy:53 into it
• Create wooden frame as in the pictures below
• Print valve_holder.stl and screw it at the bottom of the wooden quadropod then screw 12V valves into places
• Print num_layers * 4 - 1 of water_nozzle_frame.stl and nozzle_single.stl and glue them together then screw them on wooden structure so that each nozzle faces one pot
• Print 1 water_nozzle_frame_end.stl and single_nozzle.stl and glue them together and screw it on the wooden structure so it faces one pot
• Install LED strips on wooden structure so each pot has it's own light source

RPi water system

• Print 2 pipe_holder_1.stl and pipe_holder_2.stl and glue them together on the side of both liquid tanks
• Print 2 pump_holder.stl and glue it at the bottom of the tank then screw the 12V pump into it
• Print 2 water_level_holder.stl, place it on the lids of both liquid tanks and then snap an ultrasonic sensor into them
• Screw reed switches into both liquid tanks and corresponding magnets into lids
• On nutrition water tank mount PCBs for EC and pH sensors and place the sensors into the tank itself

Putting it together

Use flexible piping to connect the pot to water system as in the block diagram below:

Electronics

Refer to KiCad project in /pi_shield folder for BOM and assembly purposes of the hats.

The pot

Connect sensors / actuators to Thingy:53 control hat as in the block diagram below:

RPi water system

Connect sensors / actuators to RPi's control hat as in the block diagram below:

Attiny85

• Connect some programmer (i.e. ArduinoISP or USBasp) to Attiny85
• In platformio.ini change upload_protocol to your programmer
• You might also want to fine tune PH_MAGIC_NUMBER, TDS_A, TDS_B variables to match your sensor's characteristics
• In PlatformIO menu press "Set Fuses" in "attiny85" configuration, then click "Upload"
• Insert Attiny85 into Farm Overseers's shield

Farm Overseer setup

• Setup Ubuntu Server 20.04 (i.e via Raspberry Pi Imager)

Enable UART

• Disable serial console

sudo systemctl stop serial-getty@ttyS0.service
sudo systemctl disable serial-getty@ttyS0.service
sudo systemctl mask serial-getty@ttyS0.service

• Put below into /etc/udev/rules.d/10-local.rules

KERNEL=="ttyS0", SYMLINK+="serial0" GROUP="tty" MODE="0660"
KERNEL=="ttyAMA0", SYMLINK+="serial1" GROUP="tty" MODE="0660"

• Reload udev rules

sudo udevadm control --reload-rules && sudo udevadm trigger

• Add user to tty (edit parts in "<>")

sudo adduser <USER> tty

• Delete below from /boot/firmware/cmdline.txt

console=serial0,115200

• Add below to /boot/firmware/config.txt

dtoverlay=disable-bt

Enable 1-Wire

• Add below to /boot/firmware/config.txt

dtoverlay=w1-gpio,gpiopin=4

ROS2

• Install ROS2 Foxy Base version
• Clone this repo to your home directory (/home/$USER/TODO)
• Build ROS components:

cd ~/TODO/ros_workspace && colcon build

• Place ROS setups in your .bashrc (edit parts in "<>")

source /opt/ros/foxy/setup.bash
source /home/<USER>/TODO/ros_workspace/install/setup.bash

Mosquitto

• Install mosquitto 2.0

sudo add-apt-repository -y ppa:mosquitto-dev/mosquitto-ppa
sudo apt install mosquitto
sudo systemctl enable mosquitto

zigbee2mqtt

• Install zigbee2mqtt and set it to start as a daemon on boot. Use following config (edit parts in "<>"):

mqtt:
  base_topic: field
  server: 'mqtt://localhost'

serial:
  port: <YOUR ZIGBEE DONGLE PORT>

advanced:
    network_key: GENERATE

external_converters:
  - fc.js

Create file /opt/zigbee2mqtt/data/fc.js and paste following into it:

const fz = require('zigbee-herdsman-converters/converters/fromZigbee');
const tz = require('zigbee-herdsman-converters/converters/toZigbee');
const exposes = require('zigbee-herdsman-converters/lib/exposes');
const reporting = require('zigbee-herdsman-converters/lib/reporting');

const definition = {
    zigbeeModel: ['FC_v0.1'],
    model: 'FC',
    vendor: 'Nordic',
    description: 'Field Controller',
    fromZigbee: [fz.temperature, fz.humidity, fz.pressure, fz.on_off, fz.level_config],
    toZigbee: [tz.on_off, tz.level_config],
    exposes: [],
    configure: async (device, coordinatorEndpoint, logger) => {
        await reporting.bind(device.getEndpoint(16), coordinatorEndpoint, ['msTemperatureMeasurement']);
        await reporting.temperature(device.getEndpoint(16), { min: 30, max: 30, change: 0 });

        await reporting.bind(device.getEndpoint(16), coordinatorEndpoint, ['msPressureMeasurement']);
        await reporting.pressure(device.getEndpoint(16), { min: 30, max: 30, change: 0 });

        await reporting.bind(device.getEndpoint(16), coordinatorEndpoint, ['msRelativeHumidity']);
        await reporting.humidity(device.getEndpoint(16), { min: 30, max: 30, change: 0 });
    },
    endpoint: (device) => {
        return { fan: 10, led1: 11, led2: 12, strat: 13, water_valve: 14, nutri_valve: 15, sensors: 16 };
    },
};

module.exports = definition;

Finishing up

• Reboot the board

sudo reboot now

Field controller setup

Open field_controller/ in VSCode with nRF Connect and with Thingy:53 connected via JLink press flash.

Run Farm Overseer's control algorithms

SSH into the Farm Overseer and run:

ros2 launch garden_meta system.launch.py

Pair field controller to Farm Overseer

With Field Controller running cd into scripts/ and run:

./pair.sh -t 300

This will enable pairing for 300 seconds and should pair with the Field Controller.