Arduino Wire.h Library May 2026

Serial.println();

void requestEvent() Wire.write("Hello Master");

Try the built-in I2C scanner (File → Examples → Wire → Scanner), then hook up a cheap OLED or RTC module. You’ll be amazed at what two wires can do. arduino wire.h library

void loop() Wire.beginTransmission(8); // Slave address 8 Wire.write("Hello Slave!"); Wire.endTransmission();

void setup() Serial.begin(9600); Wire.begin(8); // Join I2C bus with address 8 Wire.onReceive(receiveEvent); Wire.onRequest(requestEvent); Serial

if(Wire.available() >= 5) Wire.read()) >> 4; float temperature = temp_raw * 0.0625;

Wire.requestFrom(8, 13); // Request 13 bytes from slave while(Wire.available()) Serial.print((char)Wire.read()); void requestEvent() Wire.write("Hello Master")

// Configure sensor (simplified) Wire.beginTransmission(SENSOR_ADDR); Wire.write(0x26); // Control register Wire.write(0xB9); // Active, 128 samples, 2^8mbar max Wire.endTransmission(); delay(100);