Do you often forget to water your indoor plants? Or perhaps you give them too much attention and over water them?

If you do, then you should make yourself a battery-powered soil moisture monitoring stick. This monitor uses a capacitive soil moisture sensor and a 3.3V Arduino Pro Mini to continuously monitor the soil moisture level and alert you when you’re over or under watering your plants.

Two potentiometers on the board allow you to adjust and set a high and low moisture level setpoint which trigger the flashing of two LEDs to alert you. You can also easily add a buzzer to the circuit if you’d like an audible alarm as well.

You can also push a button to display the current moisture reading and the high and low level setpoints on the built-in OLED display.

With the standard setup here, the unit lasts around 15-20 days on a single charge of the 18650 battery powering it. But, by using two low power techniques, this can be extended to around 50-60 days per charge.