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Topic: Improved Esplora TFT Horizon (Read 6953 times) previous topic - next topic

kor1989

Sep 06, 2013, 12:39 am Last Edit: Sep 06, 2013, 11:44 am by kor1989 Reason: 1
Hi, I have tried to improve the Esplora TFT Horizon making it a little more sensitive to high inclination and adding also a line to represent vertical inclination. The angles are also printed to the serial port.

Quote

/*
 Created 25 August 2013 by Corrado Possieri
*/

// first of all we need to include the libraries
#include <Esplora.h>
#include <TFT.h>            // Arduino LCD library
#include <SPI.h>

// some variables that the Esplora need to work correctly
// we have to define the center of the screen
const float X0 = EsploraTFT.width()/2.0;
const float Y0 = EsploraTFT.height()/2.0;

// and the limit values for the accelerometer
// good values not considering the acceleration impressed
// to Esplora are those (you can try also the values after comment)
int xAccMin = -180; // -150;
int xAccMax = 180; //170;
int yAccMin = -180; //-147;
int yAccMax = 180; //190;
int zAccMin = -180; //-150;
int zAccMax = 180; //170;

// we need also to save in a global variable the last angle
float lastTanAngle;
float lastZIncl;

// this function will be executed once at the beginning
void setup() {
 // we need to initialize the display
 EsploraTFT.begin();
 
 // and to select the color of the background
 EsploraTFT.background(0,0,0); // black for an higher contrast
 
 // begin the serial comunication
 Serial.begin(9600);
}

// this will run over and over
void loop() {  
 // we need to read the Accelerometer values...
 int xAxis = Esplora.readAccelerometer(X_AXIS);
 int yAxis = Esplora.readAccelerometer(Y_AXIS);
 int zAxis = Esplora.readAccelerometer(Z_AXIS);
 
 // ...and to remap them in a fixed range scale
 const int scale = 1000;
 float xIncl = map(xAxis, xAccMin, xAccMax, -scale, scale);
 float yIncl = map(yAxis, yAccMin, yAccMax, -scale, scale);
 float zIncl = map(zAxis, zAccMin, zAccMax, scale, -scale);
 
 // horizontal inclination
 float horizontalAngle = atan2(xIncl, yIncl);
 // vertical inclination
 float verticalInclination = atan2(yIncl, -zIncl);
 
 // print these values to the serial port
 Serial.print("horizontal angle: ");
 Serial.println(horizontalAngle/PI*180);
 Serial.print("verical angle: ");
 Serial.println(verticalInclination/PI*180);
 Serial.println();
 
 // no we can graph the values in the tft screen
 // this value represent the offset of the line
 // which represent the ground
 float zOffset = map(zAxis, zAccMin, zAccMax, Y0, -Y0);
 // this represent the inclination respect the horizon
 float tanAngle = xIncl/yIncl;

 // first of all we have to delete the previous lines
 // drawing black lines over them
 // horizontal inclination
 EsploraTFT.stroke(0,0,0); // we draw black over the previous lines
 EsploraTFT.line(0, -X0*lastTanAngle+Y0, 2*X0, X0*lastTanAngle+Y0);
 // vertical inclination
 EsploraTFT.line(0, -X0*lastTanAngle+lastZIncl+Y0,
   2*X0, X0*lastTanAngle+lastZIncl+Y0);

 // now we can write the new lines
 // one for horizontal inclination
 EsploraTFT.stroke(0,255,0); // this line would be green
 EsploraTFT.line(0, -X0*tanAngle+Y0, 2*X0, X0*tanAngle+Y0);
 // this line would be red
 // and one for vertical
 EsploraTFT.stroke(255,0,0);
 EsploraTFT.line(0, -X0*tanAngle+zOffset+Y0, 2*X0, X0*tanAngle+zOffset+Y0);
 
 // we will save the values for the next loop iteration
 lastTanAngle = tanAngle;
 lastZIncl = zOffset;
 
 // a little delay for stability
 delay(100);
}



I hope this will help.
Happy sketching

TheKitty



kor1989

Hi, I have tried to improve a little my code adding a Processing Sketch that permits also to understand what's going on for users which does not have the LCD

The code for Arduino has little changes that permits to send a float through serial port using an union

Quote

/*
  Created 25 August 2013 by Corrado Possieri
*/

// first of all we need to include the libraries
#include <Esplora.h>
#include <TFT.h>            // Arduino LCD library
#include <SPI.h>

// some variables that the Esplora need to work correctly
// we have to define the center of the screen
const float X0 = EsploraTFT.width()/2.0;
const float Y0 = EsploraTFT.height()/2.0;

// and the limit values for the accelerometer
// good values not considering the acceleration impressed
// to Esplora are those (you can try also the values after comment)
int xAccMin = -180; // -150;
int xAccMax = 180; //170;
int yAccMin = -180; //-147;
int yAccMax = 180; //190;
int zAccMin = -180; //-150;
int zAccMax = 180; //170;

// we need also to save in a global variable the last angle
float lastTanAngle;
float lastZIncl;

// declare an union to convert from float to an array of bytes
// to send them to the serial port
union FLOAT2BYTE {
  float myFloat;
  byte byte_s[4];
} S_FLOAT;


// this function will be executed once at the beginning
void setup() {
  // we need to initialize the display
  EsploraTFT.begin();
  
  // and to select the color of the background
  EsploraTFT.background(0,0,0); // black for an higher contrast
  
  // begin the serial comunication
  Serial.begin(9600);
  // send a byte to establish contact until receiver responds
  establishContact(); 
}

// this will run over and over 
void loop() {  
  // we need to read the Accelerometer values...
  int xAxis = Esplora.readAccelerometer(X_AXIS);
  int yAxis = Esplora.readAccelerometer(Y_AXIS);
  int zAxis = Esplora.readAccelerometer(Z_AXIS);
  
  // ...and to remap them in a fixed range scale
  const int scale = 1000;
  float xIncl = map(xAxis, xAccMin, xAccMax, -scale, scale);
  float yIncl = map(yAxis, yAccMin, yAccMax, -scale, scale);
  float zIncl = map(zAxis, zAccMin, zAccMax, scale, -scale);
  
  // horizontal inclination
  float horizontalAngle = atan2(xIncl, yIncl);
  // vertical inclination
  float verticalInclination = atan2(yIncl, -zIncl);
  
  // print these values to the serial port
  sendFloat(horizontalAngle);
  sendFloat(verticalInclination);

  
  // no we can graph the values in the tft screen
  // this value represent the offset of the line
  // which represent the ground
  float zOffset = map(zAxis, zAccMin, zAccMax, Y0, -Y0);
  // this represent the inclination respect the horizon
  float tanAngle = xIncl/yIncl;

  // first of all we have to delete the previous lines
  // drawing black lines over them
  // horizontal inclination
  EsploraTFT.stroke(0,0,0); // we draw black over the previous lines
  EsploraTFT.line(0, -X0*lastTanAngle+Y0, 2*X0, X0*lastTanAngle+Y0);
  // vertical inclination
  EsploraTFT.line(0, -X0*lastTanAngle+lastZIncl+Y0,
    2*X0, X0*lastTanAngle+lastZIncl+Y0);

  // now we can write the new lines
  // one for horizontal inclination
  EsploraTFT.stroke(0,255,0); // this line would be green
  EsploraTFT.line(0, -X0*tanAngle+Y0, 2*X0, X0*tanAngle+Y0);
  // this line would be red
  // and one for vertical
  EsploraTFT.stroke(255,0,0);
  EsploraTFT.line(0, -X0*tanAngle+zOffset+Y0, 2*X0, X0*tanAngle+zOffset+Y0);
  
  // we will save the values for the next loop iteration
  lastTanAngle = tanAngle;
  lastZIncl = zOffset;
  
  // a little delay for stability
  delay(100);
}

void sendFloat(float floatToSend) {
  // we can send a float to serial port
  S_FLOAT.myFloat = floatToSend;
  for(int ii = 0; ii < 4; ii++) {
    // we have to write bytes on serial port
    Serial.write(S_FLOAT.byte_s[ii]);
  }
}

void establishContact() {
  // save the start time
  unsigned long startTime = millis();
    // until we have a response from the pc
  while (Serial.available() <= 0) {
    Serial.print('A');   // send a capital A
    // if we are waiting from more than 10 seconds
    if(millis() - startTime > 10000) {
      // we will not comunicate with computer
      break;
    }      
    delay(300);
  }
}


kor1989

#4
Sep 07, 2013, 05:19 pm Last Edit: Sep 07, 2013, 05:26 pm by kor1989 Reason: 1
And this is the Processing code that permits the communication with Arduino Esplora.
Quote

/*
 created by Corrado Possieri on 7/09/2013
*/

// import the serial library of processing
// for serial comunication
import processing.serial.*;

// rotation angles (global variables because they are updated in
// the serialEvent function
float rotateY = 0;
float rotateX= PI/3;

// global variables for serial comunication
boolean firstContact = false;
int[] serialInArray = new int[8];
int serialCount = 0; // number of bytes received

// declare the serial port
Serial myPort;

void setup() {  
 // decide the size of the window
 size(800,650,OPENGL);
 
 // list of serial ports avaliable
 println("Serial ports available");
 println(Serial.list());
 // we have to choose the Arduino one
 String portName = Serial.list()[0];
 // connect to this serial port
 myPort = new Serial(this, portName, 9600);
}

void draw () {
 // selection of the background
 background(150, 255, 150);
 // iinsert a white light
 directionalLight(255, 255, 255, 0, 1, -1);
 // we don't want any line
 noStroke();
 
 // go a little back to have a better view
 translate(400,325,-150);
 // rotations comunicated by Arduino
 rotateX(rotateX);
 rotateY(rotateY);

 // draw the floor
 pushMatrix();
 translate(0,-318,0);
 // draw a little reference system
 sistRif(50);
 // select the color of the floor
 fill(31,8,250);
 // save actual reference system
 pushMatrix();
 // draw the floor like a box
 translate(0,0,-50);
 box(5000,5000,100);
 // return to the previous reference system
 popMatrix();
 // draw some lines on the floor to have a better view
 stroke(0);
 for(int kkk=-2500; kkk<=2500; kkk=kkk+100) {
   line(kkk, -2500, 0, kkk, 2500, 0);
   line(-2500, kkk, 0, 2500, kkk, 0);
 }
 popMatrix();
}

void sistRif (float length)
{
 // draw a reference system to better understand
 // what you have done
 strokeWeight(3);
 stroke(255,0,0);
 line(0,0,0,length,0,0); // x
 stroke(0,255,0);
 line(0,0,0,0,length,0); // y
 stroke(0,0,255);
 line(0,0,0,0,0,length); // z
 noStroke();
}

// when datas are available on the serial port
void serialEvent(Serial myPort) {
 // read the byte arrived
 int inByte = myPort.read();
 // if this is the first byte clear the serial port, we have had
 // the first contact, and give this information to Arduino
 if (firstContact == false) {
   if (inByte == 'A') {
     myPort.clear();  // clear the serial port
     firstContact = true;  // connection done
     myPort.write('A'); // wait
   }
 } // if we have already had a connection...
 else {
   // ...add the last byte received to an array
   serialInArray[serialCount] = inByte;
   serialCount++;
     println(serialInArray);
     println();

   if (serialCount > 7) {
     // decode received bytes to obtain 2 floats
     int asInt1 = (serialInArray[0] & 0xFF)
           | ((serialInArray[1] & 0xFF) << 8)
           | ((serialInArray[2] & 0xFF) << 16)
           | ((serialInArray[3] & 0xFF) << 24);
     rotateY = Float.intBitsToFloat(asInt1);
     println(rotateY);
           
     int asInt2 = (serialInArray[4] & 0xFF)
           | ((serialInArray[5] & 0xFF) << 8)
           | ((serialInArray[6] & 0xFF) << 16)
           | ((serialInArray[7] & 0xFF) << 24);
     rotateX = Float.intBitsToFloat(asInt2);
     println(rotateX);
     
     // Reset serialCount
     serialCount = 0;
   }
 }
}



Excuse me but i had to divide the message into tho halves because it was too long.
In the previous message i also attached two screenshot of the Processing code.
Always hoping this will help
Happy sketching

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