Joystick.cpp

00001 //Joystick (INCOMPLETE IMPLIMENTATION)
00002 //Author: Carter Sharer 
00003 //Date: 10/18/16
00004 
00005 #include "Joystick.h"
00006 #include "mbed.h"
00007 
00008 //Member function definitions including constructor
00009 Joystick::Joystick(PinName pinA, PinName pinB) : horiz(pinA), vert(pinB) {
00010     //Wait 1 second for voltage to settle
00011     wait(1); 
00012     
00013     //(1)Set Raw Center Values, this is where the joystick sits naturaly 
00014     //set raw horizontal center to current value (average with 5 readings)
00015     //set raw vertial center to current value (average with 5 readings) 
00016     raw_hc = 0;
00017     raw_vc = 0; 
00018     
00019     //(2)Initalize the Rax Max to some value less then the real max value.  
00020     //We dont know what the max value will be until we read it, thats ok. 
00021     //But we can assume it will be greater then 0.8 (center + 0.3) so lets 
00022     //set it to that for now.  We will update this later if we see a larger value
00023     //Now do the same for the the Raw Min
00024     float delta = 0.3;
00025     rawMinH = 0;
00026     rawMaxH = 0;
00027     rawMinV = 0;
00028     rawMaxV = 0;
00029 }
00030 
00031 //Returns the scaled vertial value of joystick
00032 float Joystick::horizontal(void) {
00033     //(3)Get average val (5 samples)
00034     float avg = horiz.read();
00035     
00036     //(4)Watch for Max and Min Values, if we see a new max/min update Raw Max/Min
00037     rawMaxH = avg;    
00038     rawMinH = avg;
00039     
00040     //(5)Here we will calculate the total range (Travel) of the joystick 
00041     //using the rawMax/rawMin values we have seen thus far
00042     //Since the joystick is not symetrical we have to calculate two ranges
00043     //Calculate the range from [center, max] and [center, min]
00044     float range_pos = 0;
00045     float range_neg = 0;
00046     
00047     //(6)Here we will calculate how much our current reading is in one 
00048     //of the ranges, this will give us a percentage of our _max value we 
00049     //set in setScale. Then we can apply the scale by multiplying it by our 
00050     //scale (_max/_min). 
00051     float val;
00052     if(avg >= raw_hc) //Positive Range
00053         val = 0; 
00054     else  //Negative Range
00055         val = 0; 
00056          
00057     //(7)Here we will apply a dead zone.  If the |value| is <= our deadzone then 
00058     //set it to 0.  Otherwise we need to shift the value closer to 0 by dead zone
00059     
00060     
00061     return horiz.read();
00062 }
00063 
00064 //(8) Impliment vertial the same as you did for horizontal
00065 //Returns the scaled horizontal value of joystick
00066 float Joystick::vertical(void) {
00067     //Get average value (5 samples)
00068     float avg = vert.read();
00069     
00070     //(4)Watch for Max and Min Values, if we see a new max/min update Raw Max/Min
00071     rawMaxV = avg;
00072     rawMinV = avg;
00073     
00074     //(5)Here we will calculate the total range (Travel) of the joystick 
00075     //using the rawMax/rawMin values we have seen thus far
00076     //Since the joystick is not symetrical we have to calculate two ranges
00077     //Calculate the range from [center, max] and [center, min]
00078     float range_pos = 0;
00079     float range_neg = 0;
00080     
00081     //(6)Here we will calculate how much our current reading is in one 
00082     //of the ranges, this will give us a percentage of our _max value we 
00083     //set in setScale. Then we can apply the scale by multiplying it by our 
00084     //scale (_max/_min).
00085     float val;
00086     if(avg >= raw_vc) //find scaled pot value
00087         val = 0;
00088     else 
00089         val = 0;
00090     
00091     //(7)Here we will apply a dead zone.  If the |value| is <= our deadzone then 
00092     //set it to 0.  Otherwise we need to shift the value closer to 0 by dead zone    
00093     
00094     return vert.read();
00095 }
00096 
00097 //Set the Min and Max Values of joystick ex: -100, +100
00098 void Joystick::setScale(float min, float max) {
00099        _min = min-1; //Add 1 for round off error
00100        _max = max+1; //Add 1 for round off error
00101 }