Introduction: Plant Soil Moisture Tool

In this project we'll explain how to remake a soil moisture measurment tool with an RGB LED output. The LED's task is to signal when the plant needs water.

Step 1: STEP 1: the Parts

1 Arduino Uno

1 Breadboard

1 RGB light

1 Soil moisture sensor

3 Resistors (R= 560Ω)

8 male-to-male cables

3 male-to-female cables

Step 2: Step 2: Construction

How to setup the build for the moist sensor.

  1. Connecting the VMA303 moistsensor
    1. Connect the breadboard red + track to the UNO 5V and the black - track to the UNO GND.
    2. From the breadboard + track connect a red wire to + socket of the VMA303 moistsensor and a black wire from the - track of the breadboard to the - socket on the VMA303 moistsensor.
    3. From the S socket use a white wire to connect it to the A0 socket on the UNO.
  2. Connecting the RGB LED common anode
    1. Place the RGB LED on the breadboard and make sure the pins are each in a separate track.
    2. The longest pin on the RGB LED is the anode. Connect this one to the + track of the breadboard.
    3. The remaining pins need each a 560Ω resistor to a new track on the breadboard. Make sure these tracks are separated.
    4. The track now leading to single pin next to the anode needs to be connected to the INPUT ~9 socket on the UNO, use a white wire.
    5. The track leading to the pin between the outer pin and anode of the RGB needs to be connected to INPUT ~10 socket on the UNO, use a yellow wire.
    6. The track leading to the last pin connects to the INPUT ~11 socket on the UNO, use a green wire.

Now you finished the build and can start coding!

Step 3: STEP 3: the Code

const int analogInPin = A0;

int sensorValue = 0;

int red = 9; int green = 10;

int blue = 11;

void setup() {

// put your setup code here, to run once:


pinMode(red, OUTPUT);

pinMode(green, OUTPUT);

pinMode(blue, OUTPUT);


void loop() {

// put your main code here, to run repeatedly:

sensorValue = analogRead(analogInPin);


if(sensorValue <=300){

map(sensorValue, 0, 300, 0, 255);





if(sensorValue >300){

map(sensorValue, 300, 600, 0, 255);





if(sensorValue >=600){ map(sensorValue, 600, 700, 0, 255);






Step 4: STEP 4: the Result

This project was build by WGEJB and Sanvo.

We hope you enjoy it!