A proportional integral derivative (PID) controller that will be used to run a plant waterer. PID is a fancy way of saying that the code plays a game of 'Warmer', 'Colder' to get something to a particular value (in our example, a particular moistness). The internet is littered with examples of these things, so it is mostly a learning exercise that will use a few bits of code we've previously developed, and hopefully it will make us a little smarter along the way. This is a very lightly tweaked version of the code we used for cooking.
(There's also a bare-bones version in the repository that doesn't use a screen or encoder, and has a target moisture level that can be adjusted by setting a paramater in the code. This lower-power version can be ran from a battery for extended periods of time. This is the version used in the video)
- Raspberry Pi Pico
- SSD1351 Waveshare OLED (not needed if you're making the bare bones version)
- WGCD KY-040 Rotary Encoder (not needed if you're making the bare bones version)
- A capacitive soil-moisture sensor
- A relay switch
- A plug socket for the water pump
- A cheap fish tank water pump
Warning: Don't pump water using something that dislikes being power-cycled a lot. This is GPL code, ie NO WARRANTY
All of the pins are listed in main.py. GPIO to peripherals as follows:
| Pico GPIO | OLED |
|---|---|
| 19 | DIN/MOSI |
| 18 | CLK/SCK |
| 17 | CS |
| 20 | DC |
| 21 | RST |
(not needed if you're making the bare bones version)
| Pico GPIO | Rotary Encoder |
|---|---|
| 2 | CLK |
| 3 | DT |
| 4 | SW |
(not needed if you're making the bare bones version)
| Pico GPIO | Relay |
|---|---|
| 15 | Signal |
| Pico GPIO | Soil Sensor |
|---|---|
| 26 | A0 |
The stl files for an enclosure are on thingiverse here (Thanks Ryan!).
First flash the board with the latest version of micropython.
Then clone this repository onto your computer
git clone https://github.com/veebch/sploosh
and move into the repository directory
cd sploosh
If (and only if) you are using the bare-bones version (no screen or rotary encoder)
mv main.py withscreen.py
mv barebones.py main.py
There are a few files to copy to the pico, ampy is a good way to do it.
ampy -p /dev/ttyACM0 put ./
substitute the device name to whatever the pico is on your system.
Plug it in, pop the soil probe into the medium you are going to water, plug the watering device into the plug socket, pick a setpoint using the dial. That's it!
Here's a video outlining how it works and a timelapse of it looking after a plant for a week:
If you look at this and feel like you can make it better, please fork the repository and use a feature branch. Pull requests are welcome and encouraged.
GPL 3.0