Declaration of function cannot work in different board

Projects Programming
4

float MQCalibration(int mq_pin)
{
int i;
float val=0;

for (i=0;i<CALIBARAION_SAMPLE_TIMES;i++) { //take multiple samples
val += MQResistanceCalculation(analogRead(mq_pin));
delay(CALIBRATION_SAMPLE_INTERVAL);
}
val = val/CALIBARAION_SAMPLE_TIMES; //calculate the average value
val = val/RO_CLEAN_AIR_FACTOR; //divided by RO_CLEAN_AIR_FACTOR yields the Ro
return val; //according to the chart in the datasheet

}

*/ <-------------