Example Code for Arduino-Control Breathing Light

Hardware Preparation

• DFRduino UNO R3 (SKU: DFR0216) × 1
• Gravity: IO Expansion Shield for Arduino V7.1 (SKU: DFR0216) × 1
• Gravity: I2C RGB LED Button Module (SKU: DFR0991) × 1
• Gravity-4P I2C/UART Sensor Cable(DFR0991 is equipped with one of these lines) × 1
• USB Cable × 1

Software Preparation

• Download Arduino IDE: Click to download Arduino IDE
• Download and install the DFRobot_RGBButton-main Library
• For Arduino IDE V1.8.19 (or earlier), install the library manually: How to Add a Library ?
• For Arduino IDE V2.0.0 (or later), directly search for the "DFRobot_RGBButton-main Library" in the Library Manager and install it.

Wiring Diagram

Set I2C address and then connect the button module to the I2C interface of the UNO mainboard.

Sample Code

RGB button red on press, gradient color by sine rule on release

#include <DFRobot_RGBButton.h>
DFRobot_RGBButton RGBButton(&Wire, /*I2CAddr*/ 0x2A);//set I2C address of the button module

void setup() {
   Serial.begin(115200);
   while( ! RGBButton.begin() ){       //init
   Serial.println("Communication with device failed, please check connection!");
   delay(3000);
  }
  Serial.println("Begin ok!\n");
}

int t = 0;   // basic variation factor of RGB values
uint8_t rValue = 0, gValue = 0, bValue = 0;

void loop() {
 if( RGBButton.getButtonStatus() ) {
    RGBButton.setRGBColor(RGBButton.eRed);
    delay(100);
  } else {
    rValue = (abs(sin(3.14 * t / 180))) * 255;
    gValue = (abs(sin(3.14 * (t + 60) / 180))) * 255;
    bValue = (abs(sin(3.14 * (t + 120) / 180))) * 255;
    t += 1;
    RGBButton.setRGBColor(/*r=*/rValue, /*g=*/gValue, /*b=*/bValue);//set pulse width value of red, green and blue LEDs
    delay(100);
  }
}

Result

After uploading the codes, RGB LED presents a breathing lighting effect; it turns red when the button is pressed and back to the color of the breathing light when released.