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Topic: Arduino + processing on Ubuntu - no serial list (Read 3414 times) previous topic - next topic


I have a simple switch circuit on the Arduino and the following code:
Code: [Select]
int switchPin = 4;                       // Switch connected to pin 4

void setup() {
  pinMode(switchPin, INPUT);             // Set pin 4 as an input
  Serial.begin(9600);                    // Start serial communication at 9600 bps

void loop() {
  if (digitalRead(switchPin) == HIGH) {  // If switch is ON,
    Serial.println(1);               // send 1 to Processing
  } else {                               // If the switch is not ON,
    Serial.println(0);               // send 0 to Processing
  delay(100);                            // Wait 100 milliseconds

On the serial monitor I see rows of 1 until I hit the switch when I get 0's.

In processing my code is:
Code: [Select]
import processing.serial.*;

import processing.serial.*;
Serial myport; // Create object from Serial class

void setup() {
println("Here is a list of serial ports:");
println("List finished, opening port");
myport = new Serial(this, "ttyACM0", 9600);
void draw()

void serialEvent(Serial myport)
String inString = myport.readStringUntil( '\n' );


and what I see is:
Here is a list of serial ports:
WARNING:  RXTX Version mismatch
   Jar version = RXTX-2.2pre1
   native lib Version = RXTX-2.2pre2
List finished, opening port

Evidently, when I invoke Serial.list() the warning is printed and it returns nothing.
Then, when I hardwire in the port as ttyACM0, I still get nothing.

What is wrong?


Which Arduino do you have? What version of Processing?
The art of getting good answers lies in asking good questions.



You have an Arduino 1.0.1? Is that like a UNO+ or something?
The art of getting good answers lies in asking good questions.


May 31, 2012, 04:46 am Last Edit: May 31, 2012, 04:47 am by TideMan Reason: 1

You have an Arduino 1.0.1? Is that like a UNO+ or something?

No, that's the software version.


I had ran into the same issue a while back and i upgraded the RXTX library and the JDK on the machine which fixed things for me.

My initial indicators came from processing forum at



I finally solved this problem by taking some ideas from this thread at processing:

The main point is to replace some of the files shipped with processing with the files that are shipped with Arduino.

Step 1.  In Places on Ubuntu, navigate to:
            and rename RXTXcomm.jar to RXTXcomm.jar.old or similar
Step 1a.  Go to /linux32 and rename librxtxSerial.so to librxtxSerial.so.old
Step 1b.  Go to /linux64 and rename librxtxSerial64.so to librxtxSerial64.so.old

Step 2.  Open another Places and navigate to:

Step 3.   Copy Arduino's
                     RXTXcomm.jar to processing-1.5.1/modes/java/libraries/serial/library/
                     librxtxSerial.so to processing-1.5.1/modes/java/libraries/serial/library/linux32/
                     librxtxSerial64.so to processing-1.5.1/modes/java/libraries/serial/library/linux64/

This fixed it for me using:
Ubuntu 10.04

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