#include <Wire.h>
#define TEST_SLAVE_ADDR 0x30

void setup() {
  Serial.begin(115200);
  Wire.begin(); 
  Serial.println("STM32 Simple I2C Ping Test...");
}

void loop() {
  Serial.print("Pinging address 0x30... ");
  Wire.beginTransmission(TEST_SLAVE_ADDR);
  byte error = Wire.endTransmission(); 

  if (error == 0) {
    Serial.println("Device ACKed!"); 
  } else {
    Serial.print("Error: ");
    Serial.println(error); 
  }
  delay(2000);
}