wet-ass plants

schedule/control a drip-irrigation system – the code effectively just turns on/off a gpio pin (so you can probably do other simple things with it)

code

setup

• get an rpi and set it up
• install crontab-ui on it
• download the WAP binary
• configure it to be scheduled using crontab-ui

build

• Run make to cross-compile a debug build for the RPi 4
• Run make release=1 for a release build
• Run make all release=1 to build and install the binary on to the RPi (specify your RPi address in the Makefile)

Run ./wap to see the usage. The command that I use on my crontab:

cd $HOME/wap && ./wap 12 120000 20000

circuit

(please excuse my terrible soldering, I have no prior experience in this)

Since I didn't have a perfboard and I wanted to avoid a breadboard for long-term usage, I decided to solder up the wires over these terminal tongs for ease of visibility.

After some crappy insulation using a gaffer tape to prevent against accidental water-damange:

plumbing (literally)

drip irrigation kit

I got a kit like this that has a main 2/3" hose that you can further extend to a smaller hose that feeds into individual plants; instructions to chop and slice are fairly self-explanatory.

additional plumbing

The pipe seals are exteremely important in this system, I made use of 3 things for various different seals:

1. Cut open the mouth of the canister (where the tap used to be). Insert a 3/4" pipe holder and seal it with a silicon sealant.
2. Use pipe cement to join together the elbow joints with the PVC pipes.
3. Use thread-seal tapes for joints involving screwing in the joint threads (like the one on the valve).

water

I don't have an active tap in any of my balconies that house the plants, so I hung a water canister like this with at least 3-4L of stored water to provide enough downward pressure to reach all plants

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