Rotate Cube (Sensor)

Core Library Questions

tactileda..

in Core Library Questions • 1 year ago

Hi.

I am trying to do something that I though would be quite simple but it has quickly confused me. I have an IMU connected to an Arduino and it is sending Roll, Pitch and Yaw values to Processing over the serial port. I am trying to map these values to the RotateX,Y & Z values of a cube. The values are printing in processing but when I try to map these to the cubes rotation strange things happen, the cube flashes and bounces all over the screen. The code that I am using is below, any help would be greatly appreciated, Thanks!!
PS. this is what prints in the terminal, values range from -180 to +180 :
Sensor 0: 0.92   Roll
Sensor 1: 2.36   Pitch
Sensor 2: -51.58   Yaw

import processing.serial.*;     // import the Processing serial library
Serial myPort;                  // The serial port

float bgcolor;            // Background color
float fgcolor;            // Fill color
float xpos, ypos;            // Starting position of the ball

void setup() {
frameRate(30);
size(640,480, P3D);
background(0);
lights();
// List all the available serial ports
println(Serial.list());
myPort = new Serial(this, Serial.list()[1], 9600);

// read bytes into a buffer until you get a linefeed (ASCII 10):
myPort.bufferUntil('\n');

// draw with smooth edges:
smooth();
}

void draw() {
}

void serialEvent(Serial myPort) {
background(0);
noStroke();
pushMatrix();
translate(width/2, height/2);

// read the serial buffer:
String myString = myPort.readStringUntil('\n');
// if you got any bytes other than the linefeed:
    myString = trim(myString);

    // split the string at the commas
    // and convert the sections into integers:
    float sensors[] = float(split(myString, ','));
//println("roll: " + sensors[0] + " pitch: " + sensors[1] + " yaw: " + sensors[2] + "\t");
    // print out the values you got:
    for (int sensorNum = 0; sensorNum < sensors.length; sensorNum++) {
      print("Sensor " + sensorNum + ": " + sensors[sensorNum] + "\t");
     if (sensorNum == 0) {
       println("Roll");
       //rotateX(sensors[0]);

     }
     if (sensorNum == 1) {
       println("Pitch");
       //rotateY(sensors[1]);

     }
     if (sensorNum == 2) {
       println("Yaw");
       //rotateZ(sensors[2]);
     }

    }
    // add a linefeed after all the sensor values are printed:
    println();
    box(100);
    popMatrix();
    if (sensors.length > 1) {
      rotateX(sensors[0]);
      rotateY(sensors[1]);
      rotateZ(sensors[2]);
    }
    // send a byte to ask for more data:
    myPort.write("A");
}

Replies(2)

Jonny Stu..

Re: Rotate Cube (Sensor)

1 year ago

The rotate() functions expect data in radians (where 2 * pi is a full circle) and I'm guessing if your sensors return a value in degrees. This means that a 6 degree change in your sensor gives almost a full circle of rotation. It should be better if you do e.g.:

rotateX(radians(sensors[0]));

Even better would be to convert to radians when you read from the serial port to save doing the calculation every frame.

tactileda..

Re: Rotate Cube (Sensor)

1 year ago

Thanks Jonny,

That worked fine! I converted the degs to radians in arduino and these are now mapping to the rotation of the cube in Processing...

float xx,yy,zz;
import processing.serial.*;     // import the Processing serial library
Serial myPort;                  // The serial port

float bgcolor;            // Background color
float fgcolor;            // Fill color
float xpos, ypos;            // Starting position of the ball

void setup() {
size(640,480, P3D);

// List all the available serial ports
println(Serial.list());

myPort = new Serial(this, Serial.list()[1], 9600);

// read bytes into a buffer until you get a linefeed (ASCII 10):
myPort.bufferUntil('\n');

// draw with smooth edges:
smooth();
}

void draw() {
background(0);
noStroke();
translate(width/2, height/2);
pushMatrix();
rotateX(yy);//pitch
rotateY(zz);//yaw
rotateZ(xx);//roll
box(50, 20, 300);
popMatrix();
println("roll: " + xx);
println("pitch: " + yy);
println("Yaw: " + zz);
}

void serialEvent(Serial myPort) {
// read the serial buffer:
String myString = myPort.readStringUntil('\n');
// if you got any bytes other than the linefeed:
    myString = trim(myString);

    // split the string at the commas
    // and convert the sections into integers:
    float sensors[] = float(split(myString, ','));
//println("roll: " + sensors[0] + " pitch: " + sensors[1] + " yaw: " + sensors[2] + "\t");
    // print out the values you got:
    for (int sensorNum = 0; sensorNum < sensors.length; sensorNum++) {
      //print("Sensor " + sensorNum + ": " + sensors[sensorNum] + "\t");
      if (sensorNum == 0) {
        xx = sensors[0];
      }
      if (sensorNum == 1) {
        yy = sensors[1];
      }
      if (sensorNum == 2) {
        zz = sensors[2];
      }

    }
    // add a linefeed after all the sensor values are printed:
    //println();

    // send a byte to ask for more data:
    myPort.write("A");
}

Top Reply