Automatic garden watering system

Table of contents

• General
• Running
• .env
• Default timeouts
• Debugging

General

This project consists of a Raspberry Pi 4 running Ubuntu server (x64) that is connected to various floaters inside 2 water tanks and to various relays that control solenoid valves. Here's some specific info:

• Valves 1 - 4, 8 and 9 are for watering the garden
• Rain is a property set to define that it will or is currently raining for certain conditions to occur
• Tap water can be manually activated or deactivated, equals to Valve 5
• Pump is to manually activate or deactivate it, equals to Valve 6
• Letting water fall back down from tank 2 to 1 is done with Valve 7
• There are 5 floaters, three in the first tank and two in the second

GPIO pins are always written in BCM pin numbers.

Running

You need to run this with root. Else GPIO access won't be granted. I've configured pm2 to start the process on startup with sudo:

sudo -s
pm2 startup
pm2 start main.js --name "Watering System" --watch
pm2 save

.env

Here's an example for the .env file:

WS_ENV=test
WS_PORT=3000
WS_MANUAL_TIMEOUT=28800000
WS_VALVE1_TIMEOUT=120000
WS_VALVE2_TIMEOUT=120000
WS_VALVE3_TIMEOUT=120000
WS_VALVE4_TIMEOUT=120000
WS_VALVE8_TIMEOUT=120000
WS_VALVE9_TIMEOUT=120000
WS_TAPWATER_TIMEOUT=172800000
WS_PUMP_TIMEOUT=1200000
WS_TRANSFER_TIMEOUT=1200000

Default timeouts

Designation	Time	ms
Manual mode	8 hours	28800000
Valve 1	2 mins	120000
Valve 2	2 mins	120000
Valve 3	2 mins	120000
Valve 4	2 mins	120000
Valve 8	2 mins	120000
Valve 9	2 mins	120000
Tap water	48 hours	172800000
Pump	20 mins	1200000
Transfer	20 mins	1200000

Debugging

The PI sends a 3.3V current from the GPIO pins and is capable of measuring if a circuit is closed or not when the other end connects to Ground. The voltage is so minimal that you do not feel it on your hands, so it's safe to work with it. You should therefore be able to check the various connections of the floaters circuit for 3.3V (not the circuit after the relays, which is connected to 24V), and whenever a voltage doesn't make sense, you'd be closer to the source of the problem.