RaspberryPi mit Arduino koppeln

Arduino:

int i = 0;   // for incoming serial data

void setup() {
        Serial.begin(9600);                  // opens serial port, sets data rate to 9600 bps
}

void loop() {
       
        if (Serial.available() > 0) {       // send data only when you receive data:
                
                i = Serial.read();          // read the incoming byte:
              
                Serial.println(i, DEC);     // say what you got:
        }

Raspberry Pi: