I am facing the following error in Processing application off and on, sometimes it works perfectly.
Error, disabling serialEvent() for COM2
null
Here are the codes:
Arduino's:
void setup() {
Serial.begin(9600);
}
void loop() {
int sensorValue1 = analogRead(A0);
int sensorValue2 = analogRead(A1);
Serial.print(sensorValue1);
Serial.write("-");
Serial.println(sensorValue2);
delay(1);
}
Processing's:
import processing.serial.*;
Serial myPort; // The serial port
void setup () {
size(1043, 102);
background(255);
myPort = new Serial(this, Serial.list()[1], 9600);
println(Serial.list());
myPort.bufferUntil('\n');
}
void draw () {
// everything happens in the serialEvent()
}
void serialEvent (Serial myPort) {
background(255);
String inString = myPort.readStringUntil('\n');
if (inString != null) {
inString = trim(inString);
// String inByte = inString;
int[] inStr = int(split(inString,'-'));
println(inStr);
fill(0);
rect(10,2,inStr[0],46);
rect(10,52,inStr[1],46);
fill(255);
rect(400,14,245,21);
fill(0);
textAlign(CENTER);
textSize(14);
text("1st value: "+inStr[0]+" 2nd value: "+inStr[1],width/2,30);
}
}
When I remove following part of code, the application works fine.
fill(0);
rect(10,2,inStr[0],46);
rect(10,52,inStr[1],46);
fill(255);
rect(400,14,245,21);
fill(0);
textAlign(CENTER);
textSize(14);
text("1st value: "+inStr[0]+" 2nd value: "+inStr[1],width/2,30);
I am using Win7, Processing ver2.2.1 & Arduino ver1.0.5-r2.
I'm new to all serial communication stuff..
You have to surround your serialEvent method body in try-catch:
void serialEvent (Serial myPort) {
try {
...
your code
...
}
catch(RuntimeException e) {
e.printStackTrace();
}
}
There is probably an exception thrown from your serialEvent implementation.
Put your code inside the draw() function, just use serialEvent() to change the value of variables (remember to initialize them).
Make inStr a global variable, you can define its length and initialize it maybe with 0.
Should be something like:
import processing.serial.*;
Serial myPort; // The serial port
int[] inStr = {0,0};
void setup () {
size(1043, 102);
background(255);
myPort = new Serial(this, Serial.list()[1], 9600);
println(Serial.list());
myPort.bufferUntil('\n');
}
void draw () {
fill(0);
rect(10,2,inStr[0],46);
rect(10,52,inStr[1],46);
fill(255);
rect(400,14,245,21);
fill(0);
textAlign(CENTER);
textSize(14);
text("1st value: "+inStr[0]+" 2nd value: "+inStr[1],width/2,30);
}
void serialEvent (Serial myPort) {
String inString = myPort.readStringUntil('\n');
if (inString != null) {
inString = trim(inString);
inStr = int(split(inString,'-'));
println(inStr);
}
}
In the future try not to use serialEvent to do the work of draw()
// at the top of the program:
float xPos = 400; // horizontal position of the graph
float yPos = 300; // vertical position of the graph
float zPos = 300;
float regiypos = yPos;
float regizpos = zPos;
int par = 5;
import processing.serial.*;
Serial myPort; // The serial port
int lf = 10; // Linefeed in ASCII
String myString = null;
float num;
void setup () {
size(800, 600); // (Width, Height) window size
myPort = new Serial(this, "COM4", 115200);
background(#081640);
noLoop(); //-- Ne fussál folyamatosan
}
void draw () {
// draw the line in a pretty color:
stroke(#A8D9A7);
line(xPos-par,regiypos, xPos, yPos); // (x1,y1,x2,y2) Origó a bal felső sarokban
regiypos = yPos; // ami most új volt azt megőrzi, hogy legyen mivel összekötni
stroke(#ff00A7);
line(xPos-par,regizpos, xPos, zPos);
regizpos = zPos;
// at the edge of the screen, go back to the beginning:
if (xPos >= width) {
xPos = 0;
// clear the screen by resetting the background:
background(#EDA430);
background(#081640);
}
else {
// increment the horizontal position for the next reading:
xPos+=par;
}
}
void serialEvent (Serial myPort) { //-- Nem fut folyamatosan, hanem csak akkor ha adat érkezik, mert akkor meghívodik ez a fv.
// get the byte:
// float inByte = myPort.read();
// print it:
// println(inByte);
myString = myPort.readStringUntil(lf);
if (myString != null) {
print(myString); // Prints String
String[] q = splitTokens(myString,":");
if (q.length==2){
print(q[0]); // Acceltoroll print
print(q[1]); // Gyrotoroll print
num=float(q[0]); // Converts and prints float
yPos = height/2 - num;
num=float(q[1]); // Converts and prints float
zPos = height/2 - num;
redraw(); //-- Melynek a végén van a redraw() parancs, mely egyszer lefutattaja a draw()-ban lévő részt.
}
}
}
And the highlighted part is this:
if (q.length==2) {
print(q[0]); // Acceltoroll print
print(q[1]); // Gyrotoroll print
num=float(q[0]); // Converts and prints float
yPos = height/2 - num;
num=float(q[1]); // Converts and prints float
zPos = height/2 - num;
redraw(); //-- Melynek a végén van a redraw() parancs, mely egyszer lefutattaja a draw()-ban lévő részt.
}
This will solve your problem. The problem is that q[1] may not exist if the buffer is full and begins to overwrite the data...
Just paste the code to notepad++ to get a better view.
