PC to Arduino: Serial BOF and EOF control codes

(First of all, I’ve tried to train myself to refer to the data sent over the serial port as ‘command codes’ but I always find myself lapsing into calling them ‘control codes.’ So I give up for today.)

Here’s what I send from processing:

          int outgoingbyte = 125;
          myPort.write(outgoingbyte);
          for (int i = 1; i<=cnum; i++){
               seg_calc(i);
               println(str(i-1)+"."+str(cc1)+"."+str(cc2)+"."+str(cc3)+"."+str(cc4));
               myPort.write(cc1);
               myPort.write(cc2);
               myPort.write(cc3);
               myPort.write(cc4);
          }
          outgoingbyte = 126;
          myPort.write(outgoingbyte);

And here’s how the Arduino receives it:

	if (Serial.available() < 1) {
          return;
        } 
        digitalWrite(13,HIGH);

	incomingByte = Serial.read();
        /*
        if (incomingByte == 125){
          digitalWrite(13,HIGH);
          delay(5000);
          cc_count = 0;
        }
        if (incomingByte == 126) {
          digitalWrite(13,LOW);
        }
        cc_count = cc_count + 1;
        cc_list[cc_count] = incomingByte;
        */

As you can see, I commented out most of the code here because it wasn’t working and I needed to test it. What the uncommented code does is turn on the pin 13 LED to confirm when serial data is received. And yes, the LED went ON, so I know that data is coming over.

Originally, however, the code was written to turn on the pin 13 LED when a value of 125 (= BOF = Beginning Of File) is received and turn off the pin 13 LED when a value of 126 (= EOF = End of File) is received. It wasn’t doing that.

So where am I? I know that data is going over the serial port, but apparently it’s not being read the same way it was written. Now I need to find out why, or find a way to work around the problem.

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About engineerzero

Once and future engineer.
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