Prepare

D-duino x1

18650 shield x1

Soil moisture sensor x1

Connect and have test like this.

Connect moisture sensor's Vcc to D-duino 3V3 pin.

Connect moisture sensor's GND to D-duino GND pin.

Connect moisture sensor's data pin to D-duino A0 pin.

First let's test sensor status in water.

There is a big different, is it?

Please follow this github project :Moisture

There are many projects about D-duino on this github.

Please go to ThingSpeak and build a new channel with 1 chart.
Remember your API key and copy it to the code.

After changing WiFi ssid and password and API key you can upload code into D-duino.

Wait several seconds you will find the data displayed on the oled.

Here I set it upload to ThingSpeak every 60 seconds. It may only last for several hours.

You can expand time by fix codes.

Not only moisture sensor but also other sensor is OK!