Plant health sensor

A‌re your plants thirsty? 

This sensor will show you the moisture level of 6 plants (and can even help you water them).

device
M‌oisture percentage 

Get a deeper reading of the soil's moisture levels, and log it over time. 

Capacitive sensors

These sensors use the same technology as touchscreens, which makes them more rust resistant. 

Check on 6 plants

You can connect between 1 and 6 soil sensors.

Automated watering

As an upgrade, you could even automatically water your plants.

  • An early prototype

    Connected up to 6 sensors

Building the sensor

Approximate building time: 10 to 30 minutes.

Connect the moisture sensor(s)

  • Connect the soil sensor to pin A0. If you have more sensors, connect them to A1, A2 and A3 in similar fashion.

Connect the OLED display

Connect the screen's SDA (data) pin to signal pin A4 on the expansion board.
Connect the screen's SCL (clock) pin to signal pin A5 on the expansion board.
Connect the screen's GND (ground) pin to any ground pin (black color) on the expansion board.
Connect the screen's VDD (positive) pin to any VCC pin (red color) on the expansion board.

Plug in the Arduino

Plug in the RF-Nano Arduino

Plug the RF-Nano into its socket. The USB connector should be on the outside of the main board.

Open the Candle Manager

Visit the controller, and click on the "Create Candle" link to open the Candle manager. Follow the step by step guide. It will help you upload the code to your new creation.

Add your new device

Visit the Candle controller and on the things page press the (+) icon. Your new creation should be available. Optionally, select which of its properties you'd like to have in the spotlight. Click on "save" to complete the proces.

Done!

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Shopping list

You can buy all the parts yourself, for example on Aliexpress.com.
Small OLED screen
Jan 21, 2019

This small screen is built with OLED technology. It uses very little power.

RF-Nano Arduino
Aug 10, 2018

The RF-Nano is an Arduino Nano with built-in wireless connectivity. It's the brain of all Candle devices.

Soil sensor
Aug 07, 2018

This is a capacitive soil sensor. The advantage of this type is that it does not rust. It works the same way that a touchscreen…

Expansion board
Aug 06, 2018

This expansion board makes it easy to connect everything by just plugging in wires.