Home of Buys de Barbanson

Automated plant watering system

In 2016 I started building an automated watering system to water my plants.

First prototype, 2016

The first version has three pumps which were driven by a relay and the moisture level of the plants is measured by a simple soil resistance sensor connected to a 8 bit analog to digital converter. The frame holding everything together is made out of Lego. Every plant has its own pump and flow-sensor (YF-S402) which makes it possible to pump precise amounts of water. The relays and sensors are controlled by an Arduino UNO which is controlled by a Raspberry PI over USB. The Raspberry PI runs a Telegram bot which allows me to run the pumps remotely and obtain plots which show the moisture level of the plants over time. First watering system prototype, with flow sensors and a lego frame.Telegram bot controlling first watering system prototype. Plots are made using Matplotlib, datapoints are obtained from an 8bit ADC. lines are generated using a sliding window averaging filter.

Additions 2018

The following changes were made:
  • Control panel
  • 15bit analog to digital converters instead of 8bit (ADS1115)
  • 8 pumps and flow-sensors
  • Arduino mega
  • 2x ESP8266 to measure soil moisture and send it over WiFi to reduce the amount of cables
  • Capacitive soil moisture measurement instead of resistive.
  • Three color E-ink display to show current moisture levels and last moment of watering
Main pumping unit with 8 pumps and 8 flow sensorsThree color WaveShare E-Ink display showing plant statusMain control panel for manual watering control. The big gauges show 5V and 12V rail voltage and current.External measurement unit which sends moisture data using WiFi. The sensors and ADC run on 5V, and the ESP8266 on 3.3v, therefore a logic-level converter is used.Every plant has one capactive moisture sensor and a perforated 3d printed ring which distributes water across the pot.Moisture measurements of a single plant. On the y-axis the value from the 15 bit ADC. The vertical blue lines indicate when the plant was watered, a blue line is followed by a low ADC readout caused by the sudden change of soil capacitance.
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