Tag Archives: Plant Monitor

This DIY moisture monitor

 will help keep your houseplants alive


With spring just around the corner, it’s never too early to start thinking about planting.


Writing for Popular Mechanics, Alexandra Chang explained why she recently created an open-source, Arduino-powered DIY moisture monitor to ensure that her plants received the optimal living conditions.

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“My perennials always died because I watered them too little or too much, or put them somewhere too dark or too hot,” she says. 

“[So] I vowed to keep my plants alive [and] turned to Arduino. I’d been looking for an excuse to try out this microcontroller platform, which I knew could be programmed to do a lot of cool things. Why not use it to save my ailing amaryllis?”

According to Chang, the project took a single afternoon and resulted in a smart sensor that was capable of reading and displaying soil-moisture levels, light intensity and temperature. 

For the build, the Maker turned to no other than an Arduino Uno Starter Kit (ATmega328) which included the following parts:

  • Solderless breadboard ($5)
  • Assorted wires ($7)
  • Thermistor ($2)
  • Photoresistor ($1)
  • 10K-ohm resistors ($8 per pack)
  • Potentiometer ($1)
  • LCD display ($10)

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After finding instructions for a number of Arduino-based plant sensors online, such as the GardenBot, the ArduGarden and Soil IQ’s solar-powered sensor, Chang converged certain elements from each to devise something that suited her own skill level and needs.

The DIY gardening device features two soil probes responsible for measuring how much the soil resists the flow of electricity — or how moist it is. By adding a photoresistor (light sensor) and a thermistor (temperature sensor), then connecting them to a programmed Arduino, she was left with a gadget that could monitor the environment of a single plant. Meanwhile, an LCD display was used to show its moisture, temperature, and light readings in variable resistance values.

Interested in learning more? Head over to the project’s official writeup in Popular Mechanics here.