RPG.cpp

00001 /**
00002 * =============================================================================
00003 * Rotary Pulse Generator class (Version 0.0.1)
00004 * =============================================================================
00005 * Copyright (c) 2012 Christopher Anderson
00006 *
00007 * Permission is hereby granted, free of charge, to any person obtaining a copy
00008 * of this software and associated documentation files (the "Software"), to deal
00009 * in the Software without restriction, including without limitation the rights
00010 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00011 * copies of the Software, and to permit persons to whom the Software is
00012 * furnished to do so, subject to the following conditions:
00013 *
00014 * The above copyright notice and this permission notice shall be included in
00015 * all copies or substantial portions of the Software.
00016 *
00017 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00018 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00019 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00020 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00021 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00022 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00023 * THE SOFTWARE.
00024 * =============================================================================
00025 */
00026  
00027 #include "RPG.h"
00028 #include "mbed.h"
00029 
00030 /**
00031  * Constructor(Channel A input pin, Channel B input pin, Pushbutton input pin)
00032  */
00033 RPG::RPG(PinName pA, PinName pB, PinName pPB)
00034     : chRPG(pA, pB), PB(pPB)
00035     {
00036         chRPG.input();
00037         chRPG.mode(PullUp);
00038         PB.mode(PullUp);
00039         wait_us(10);
00040         RPGO = chRPG;
00041     }
00042     
00043 /**
00044  *Destructor
00045  */
00046 RPG::~RPG()
00047 {}
00048 
00049 /**
00050  *reads and debounces push button returns bool result
00051  */
00052 bool RPG::pb()
00053 {
00054     int check = PB;
00055     wait_us(5);
00056     if((!check) && !PB)
00057     {
00058         return true;
00059     }
00060     else return false;
00061 }
00062 
00063 /**
00064  *Determines direction of rotation returns:
00065  *1 for clockwise
00066  *-1 for counter-clockwise
00067  *0 for no rotation
00068  */
00069 int RPG::dir()
00070 {
00071     int dir = 0;
00072     RPGO = chRPG;
00073     wait(.005);
00074     RPGN = chRPG;
00075     if(RPGN != RPGO)
00076     {
00077         if((RPGN & 1) != (RPGO >> 1)) dir = 1;
00078         else dir = -1;
00079     }
00080     else dir = 0;
00081     RPGO = RPGN;
00082     return dir;
00083 }