   delay(20);
   Serial.begin(115200);
   Wire.begin(4, 5);
+  // default
+  //Wire.setClock(100000);
+  //twi_setClock(100000);
+  twi_setClock(400000);
+
   delay(200);
 
   sensor_data._salt = 0;

void loop ()
{
  count++;
  
  sensor_data._salt++;
  sensor_data.pls++;
  sensor_data.ct1++;

  Wire.beginTransmission(SLAVE_ADDRESS);
  I2C_writeAnything(sensor_data);
  Wire.endTransmission();
  wtime = wtime + (micros() - now);

  delay(2);

  unsigned long now2 = micros();
  if (Wire.requestFrom(SLAVE_ADDRESS, sizeof(sensor_data_copy)))
  {
    I2C_readAnything(sensor_data_copy);
  }
  rtime = rtime + (micros() - now2);

  if ( sensor_data._salt != sensor_data_copy._salt ||
       sensor_data.pls   != sensor_data_copy.pls ||
