#include <Wire.h>

#define BUFFER_SIZE 32
char receivedMessage[BUFFER_SIZE];

void setup() {
  Wire.begin(8); // slave address from the master
  Wire.onReceive(receiveEvent);
  Serial.begin(9600);
  while (!Serial);
  Serial.println("Slave ready to receive messages...");
}

void loop() {
  // Nothing here; work happens in receiveEvent()
}

void receiveEvent(int howMany) {
  if (howMany > 0 && howMany < BUFFER_SIZE) {
    for (int i = 0; i < howMany; i++) {
      receivedMessage[i] = Wire.read();
    }
    receivedMessage[howMany] = '\0';

    Serial.print("Received from master: ");
    Serial.println(receivedMessage);
  } else {
    // If message too big or empty, clear buffer
    while (Wire.available()) {
      Wire.read();
    }
    Serial.println("Received invalid or oversized message.");
  }
}