"if...don't send" serial question

Forum 2005-2010 (read only) Hardware Interfacing
1

I have a data range of 0-180 that is being read via analog sensors which I send via serial to another Arduino board. I would like to reduce the traffic on the Serial connection by telling the board not to send data if it hits "0". How would I write the Arduino code to tell it to not send data if 0 is being read? I have the following so far which will also send "0" due to sending all values:

  val = analogRead(fsrOne); 
  if (val >= 0 && val < 200) {
    val = map(val, 0, 199, 0, 0);
  }  else if (val >= 200 && val < 800) {
    val = map(val, 200, 799, 20, 120);
  } else if (val >= 800 && val < 1024) {
    val = map(val, 800, 1023, 120, 180);
  }
  
  Serial.write(val);     // the raw analog reading
2

Why not use a simple if-statement?

if (val > 0) {
  Serial.write(val);
}
3

Thanks, it looks simple enough.

4

I've done something similar in the past by setting the last value sent in a variable, and then comparing the new value to the previous value sent. If there is no change, then nothing was sent. Only a different value got sent to cut down on traffic.