Problem with Recieving serial Strings ending with LF or CR's.

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Problem with Recieving serial Strings ending with LF or CR's.

in Core Library Questions • 2 years ago

i have a device that outputs serial data like a string, and ends with 0D then 0A(ASCII:Linefeed then Carriage Return). When using the code below, it seems to be ignoring them and never prints a line or outputs. Hyper-terminal Reads the data fine.

PLEASE HELP!

ASCII DATA BEING SENT TO PROCESSING( one line):

00000000: 30 37 2f 30 36 2f 31 31 | 20 20 31 32 3a 33 33 3a 07/06/11 12:33:

00000010: 32 33 20 20 20 31 30 30 | 30 20 20 20 20 20 42 41 23 1000 BA

00000020: 54 54 45 52 59 20 46 41 | 49 4c 45 44 0d 0a TTERY FAILED..

Hyper-Terminal Output:

07/06/11 12:33:23 1000 BATTERY FAILED

import processing.serial.*;
PrintWriter output;
int lf = 10; // Linefeed in ASCII
String ComPortString = null;
Serial myPort; // The serial port
void setup() {
output = createWriter("Log-" + DateTimestamp() + ".txt");
// List all the available serial ports
println(Serial.list());
// I know that the first port in the serial list on my mac
// is always my Keyspan adaptor, so I open Serial.list()[0].
// Open whatever port is the one you're using.
myPort = new Serial(this, Serial.list()[0], 9600);
myPort.clear();
// Throw out the first reading, in case we started reading
// in the middle of a string from the sender.
ComPortString = myPort.readStringUntil(lf);
ComPortString = null;
output.println(timestamp() + " " + "Logging Started");
}
void draw() {
while (myPort.available() > 0) {
ComPortString = myPort.readStringUntil(lf);
if (ComPortString != null) {
println(ComPortString);
output.println(timestamp() + " " + ComPortString);
output.flush();
}
}
}
String timestamp() {
Calendar now = Calendar.getInstance();
return String.format("%1$tH:%1$tM:%1$tS", now);
}
String DateTimestamp() {
Calendar now = Calendar.getInstance();
return String.format("%1$tm%1$td%1$ty_%1$tH%1$tM%1$tS", now);
}
void stop() {
output.flush(); // Write the remaining data
output.close(); // Finish the file
super.stop();
}

Replies(1)

myupctoys

Re: Problem with Recieving serial Strings ending with LF or CR's.

2 years ago

Hi,

Try setting a "bufferuntil" character of 10 ie 0x0A

byte buffer_char = 10;

After you've opened the serial port successfully in setup do something like this.

myPort.bufferUntil(buffer_char);

Then a serialEvent(Serial Port) routine which you will write will be triggered when that character is seen. Something like below.

private void serialEvent(Serial Port)
{
String input = Port.readString();
println("Response");
if(input.length() > 0)
      {
      if(input != null)
      {
println(trim(input));
strarray[0] = trim(input);
pointer++;
if (pointer == 4)
      {
      pointer = 0;
      }
}
else
      {
      println("Null");
      }
}
}

Grab the data from the buffer

String input = Port.readString();

Then use trim() to get rid of non printable characters like 0xOD.

Stefan

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