December 20, 2020

Plant Watering Smart Buckets

Going away? Need to remotely water your plants?! You need one of these!

Plant Watering Smart Buckets

Going away? Need to remotely water your plants?! You need one of these!

Status Operational
Platform D1 Mini ESPHome
Budget $50
Date Completed December 2020

Summary of operation

Basically it's a bucket of water with a small submersible water pump that sits in the bottom and waters the plant via clear vinyl hose.

To make it remotely operate, and for some extra features, it also includes a sensor to measure the soil moisture, as well as a level meter in the bucket.

It runs ESPHome software for operation via Home Assistant!

It does need a 12VDC power supply to run the pump - so unfortunately needs to plug in. But hey - maybe a future improvement could be battery power.

Parts used

Some engineering detail

The circuit board is really basic. It just connects a GPIO output from the D1 Mini to the relay board. The 2 headers are i2c with power and ground. The soil sensor is i2c and so is the laser range finder for the bucket water depth.

Made it using the cold/acetone toner transfer method and etched in warm ammonium persulfate (first photo). Finished an assembled PCBs shown in the following images.

Future improvements

Some ideas for future improvements:

  • Battery operation. Would need timer/interrupt method to wake up the device say every couple of hours to see if watering has been cued in the meantime. Otherwise the WiFi will run the battery flat!
  • Better soil sensors. I don't know what it is with soil sensors - but they're all pretty average. I think there's better types which go on a leaf to measure light passing through?
  • Peristaltic style pump for a measured dose of water. These pumps I used were just cheaper and easier. But not accurate in terms of water they deliver as they're very dependent on the head pressure of the pipework.
  • Button to press to water locally from the unit.