519_La

Fork of Joystick_skeleton by Carter Sharer

Joystick.cpp

Committer:
chirags
Date:
2016-11-13
Revision:
6:7a0edb75e7fd
Parent:
5:4e531d160998

File content as of revision 6:7a0edb75e7fd:

//Joystick (INCOMPLETE IMPLIMENTATION)
//Author: Carter Sharer 
//Date: 10/18/16

#include "Joystick.h"
#include "mbed.h"

//Member function definitions including constructor
Joystick::Joystick(PinName pinA, PinName pinB) : horiz(pinA), vert(pinB) {
    //Wait 1 second for voltage to settle
    wait(1); 
    
    //(1)Set Raw Center Values, this is where the joystick sits naturaly 
    //set raw horizontal center to current value (average with 5 readings)
    //set raw vertial center to current value (average with 5 readings) 
    raw_hc = 0;
    raw_vc = 0; 
    
    for (int i = 0; i<5; i++) {
        raw_hc += horiz.read();
        raw_vc += vert.read();
    }
    raw_hc /= 5;
    raw_vc /= 5;
    
    
    //(2)Initalize the Rax Max to some value less then the real max value.  
    //We dont know what the max value will be until we read it, thats ok. 
    //But we can assume it will be greater then 0.8 (center + 0.3) so lets 
    //set it to that for now.  We will update this later if we see a larger value
    //Now do the same for the the Raw Min
    float delta = 0.3;
    rawMinH = raw_hc - delta;
    rawMaxH = raw_hc + delta;
    rawMinV = raw_vc - delta;
    rawMaxV = raw_vc + delta;
}

//Returns the scaled vertial value of joystick
float Joystick::horizontal(void) {
    //(3)Get average val (5 samples)
    float avg = 0;
    
    for (int i = 0; i < 5; i++) {
        avg += horiz.read();
    }
    avg /= 5;
    //(4)Watch for Max and Min Values, if we see a new max/min update Raw Max/Min
    if(avg > rawMaxH) {
        rawMaxH = avg; 
    }
    else if(avg < rawMinH) {
        rawMinH = avg;
    }
    
    //(5)Here we will calculate the total range (Travel) of the joystick 
    //using the rawMax/rawMin values we have seen thus far
    //Since the joystick is not symetrical we have to calculate two ranges
    //Calculate the range from [center, max] and [center, min]
    float range_pos = rawMaxH - raw_hc;
    float range_neg = raw_hc - rawMinH;
    
    //(6)Here we will calculate how much our current reading is in one 
    //of the ranges, this will give us a percentage of our _max value we 
    //set in setScale. Then we can apply the scale by multiplying it by our 
    //scale (_max/_min). 
    float val;
    if(avg >= raw_hc) //Positive Range
        val = ((avg - raw_hc)/range_pos)*(_max - 1); 
    else  //Negative Range
        val = ((raw_hc - avg)/range_neg)*(_min + 1); 
         
    //(7)Here we will apply a dead zone.  If the |value| is <= our deadzone then 
    //set it to 0.  Otherwise we need to shift the value closer to 0 by dead zone
    
    
    return val;
}

//(8) Impliment vertial the same as you did for horizontal
//Returns the scaled horizontal value of joystick
float Joystick::vertical(void) {
    //Get average value (5 samples)
    float avg = 0;
    
    for(int i = 0; i < 5; i++) {
        avg += vert.read();
    }
    avg /= 5;
    //(4)Watch for Max and Min Values, if we see a new max/min update Raw Max/Min
    if(avg > rawMaxV) {
        rawMaxV = avg; 
    }
    if(avg < rawMinV) {
        rawMinV = avg;
    }
    
    //(5)Here we will calculate the total range (Travel) of the joystick 
    //using the rawMax/rawMin values we have seen thus far
    //Since the joystick is not symetrical we have to calculate two ranges
    //Calculate the range from [center, max] and [center, min]
    float range_pos = rawMaxV - raw_vc;
    float range_neg = raw_vc - rawMinV;
    
    //(6)Here we will calculate how much our current reading is in one 
    //of the ranges, this will give us a percentage of our _max value we 
    //set in setScale. Then we can apply the scale by multiplying it by our 
    //scale (_max/_min).
    float val = 0;
    if(avg >= raw_vc) //Positive Range
        val = ((avg - raw_vc)/range_pos)*(_max - 1); 
    else  //Negative Range
        val = ((raw_vc - avg)/range_neg)*(_min + 1); 
    
    //(7)Here we will apply a dead zone.  If the |value| is <= our deadzone then 
    //set it to 0.  Otherwise we need to shift the value closer to 0 by dead zone    
    return val;
}

//Set the Min and Max Values of joystick ex: -100, +100
void Joystick::setScale(float min, float max) {
       _min = min-1; //Add 1 for round off error
       _max = max+1; //Add 1 for round off error
}