The automatic snake plant watering device is a hands-off system in which your plant can be watered without any manual labor for long periods of time.
The system consists of a power supply, the main argon controller board, the soil moisture sensor board, the soil moisture sensor, a small water pump, and the water pump relay. I found this nice cereal container that just happens to work really well as a water tank. I also 3d printed this pot dish with an articulating arm to hold the tube from the pump over the edge of the pot.
In another location, we have a satellite argon board that will alert the user when this plant is being watered. Say you are at the office, but are never around at the watering time to see it working directly. You could easily place the satellite board on your desk at work and just glance over to verify that your plant is indeed being watered.
Here is the short version of how this device works.
Every sixty seconds, the argon reads the date and time from the cloud. If it is at the top of the hour, the system will read the moisture content of the soil and report that data to the cloud, where it will be logged on ThingSpeak.
Live ThingSpeak Feed (Graph): https://thingspeak.com/channels/1216704
Note: ThingSpeak Feed links to an updated version of the device, so more data is available.
If it is on a watering day, which happens every week or so, the device will check to see if it is the correct hour to water. If it is at the proper time and the moisture content of the soil is below a set threshold, the argon will turn on the water pump for the time necessary to dispense 100 mL of water.
When the system decides that it is time to water, a message is sent to the cloud saying that a watering is occurring. The satellite argon will receive this message and blink for five seconds to alert the user at the remote location that the plant is watering as it should. The satellite will then send and acknowledgement back to the cloud, causing the main board to blink for five seconds in response. This way, communication and proper function can be ensured at both ends.
Included in this project are the .STL files for 3D printing the dish/articulating arm combo to hold the watering tube. For this, you will need to print 1 dish, 1 tube holder, 3 narrow arm segments, and 2 thick arm segments. The hardware is all M5, but any size screws that fit through the holes will do the job.