Diff: QEI.cpp

Revision:

1:8658787f9ec5

Parent:

0:5c2ad81551aa

diff -r 5c2ad81551aa -r 8658787f9ec5 QEI.cpp
--- a/QEI.cpp	Thu Sep 02 16:48:55 2010 +0000
+++ b/QEI.cpp	Wed Oct 11 08:14:24 2017 +0000
@@ -1,289 +1,184 @@
-/**
- * @author Aaron Berk
- *
- * @section LICENSE
- *
- * Copyright (c) 2010 ARM Limited
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @section DESCRIPTION
- *
- * Quadrature Encoder Interface.
- *
- * A quadrature encoder consists of two code tracks on a disc which are 90
- * degrees out of phase. It can be used to determine how far a wheel has
- * rotated, relative to a known starting position.
- *
- * Only one code track changes at a time leading to a more robust system than
- * a single track, because any jitter around any edge won't cause a state
- * change as the other track will remain constant.
- *
- * Encoders can be a homebrew affair, consisting of infrared emitters/receivers
- * and paper code tracks consisting of alternating black and white sections;
- * alternatively, complete disk and PCB emitter/receiver encoder systems can
- * be bought, but the interface, regardless of implementation is the same.
- *
- *               +-----+     +-----+     +-----+
- * Channel A     |  ^  |     |     |     |     |
- *            ---+  ^  +-----+     +-----+     +-----
- *               ^  ^
- *               ^  +-----+     +-----+     +-----+
- * Channel B     ^  |     |     |     |     |     |
- *            ------+     +-----+     +-----+     +-----
- *               ^  ^
- *               ^  ^
- *               90deg
- *
- * The interface uses X2 encoding by default which calculates the pulse count
- * based on reading the current state after each rising and falling edge of
- * channel A.
- *
- *               +-----+     +-----+     +-----+
- * Channel A     |     |     |     |     |     |
- *            ---+     +-----+     +-----+     +-----
- *               ^     ^     ^     ^     ^
- *               ^  +-----+  ^  +-----+  ^  +-----+
- * Channel B     ^  |  ^  |  ^  |  ^  |  ^  |     |
- *            ------+  ^  +-----+  ^  +-----+     +--
- *               ^     ^     ^     ^     ^
- *               ^     ^     ^     ^     ^
- * Pulse count 0 1     2     3     4     5  ...
- *
- * This interface can also use X4 encoding which calculates the pulse count
- * based on reading the current state after each rising and falling edge of
- * either channel.
- *
- *               +-----+     +-----+     +-----+
- * Channel A     |     |     |     |     |     |
- *            ---+     +-----+     +-----+     +-----
- *               ^     ^     ^     ^     ^
- *               ^  +-----+  ^  +-----+  ^  +-----+
- * Channel B     ^  |  ^  |  ^  |  ^  |  ^  |     |
- *            ------+  ^  +-----+  ^  +-----+     +--
- *               ^  ^  ^  ^  ^  ^  ^  ^  ^  ^
- *               ^  ^  ^  ^  ^  ^  ^  ^  ^  ^
- * Pulse count 0 1  2  3  4  5  6  7  8  9  ...
- *
- * It defaults
- *
- * An optional index channel can be used which determines when a full
- * revolution has occured.
- *
- * If a 4 pules per revolution encoder was used, with X4 encoding,
- * the following would be observed.
- *
- *               +-----+     +-----+     +-----+
- * Channel A     |     |     |     |     |     |
- *            ---+     +-----+     +-----+     +-----
- *               ^     ^     ^     ^     ^
- *               ^  +-----+  ^  +-----+  ^  +-----+
- * Channel B     ^  |  ^  |  ^  |  ^  |  ^  |     |
- *            ------+  ^  +-----+  ^  +-----+     +--
- *               ^  ^  ^  ^  ^  ^  ^  ^  ^  ^
- *               ^  ^  ^  ^  ^  ^  ^  ^  ^  ^
- *               ^  ^  ^  +--+  ^  ^  +--+  ^
- *               ^  ^  ^  |  |  ^  ^  |  |  ^
- * Index      ------------+  +--------+  +-----------
- *               ^  ^  ^  ^  ^  ^  ^  ^  ^  ^
- * Pulse count 0 1  2  3  4  5  6  7  8  9  ...
- * Rev.  count 0          1           2
- *
- * Rotational position in degrees can be calculated by:
- *
- * (pulse count / X * N) * 360
- *
- * Where X is the encoding type [e.g. X4 encoding => X=4], and N is the number
- * of pulses per revolution.
- *
- * Linear position can be calculated by:
- *
- * (pulse count / X * N) * (1 / PPI)
- *
- * Where X is encoding type [e.g. X4 encoding => X=44], N is the number of
- * pulses per revolution, and PPI is pulses per inch, or the equivalent for
- * any other unit of displacement. PPI can be calculated by taking the
- * circumference of the wheel or encoder disk and dividing it by the number
- * of pulses per revolution.
- */
-
-/**
- * Includes
- */
 #include "QEI.h"
-
+ 
 QEI::QEI(PinName channelA,
          PinName channelB,
          PinName index,
          int pulsesPerRev,
-         Encoding encoding) : channelA_(channelA), channelB_(channelB),
+         Encoding encoding
+         ) : channelA_(channelA), channelB_(channelB),
         index_(index) {
-
+ 
     pulses_       = 0;
     revolutions_  = 0;
     pulsesPerRev_ = pulsesPerRev;
     encoding_     = encoding;
-
+    
     //Workout what the current state is.
     int chanA = channelA_.read();
     int chanB = channelB_.read();
-
+ 
     //2-bit state.
     currState_ = (chanA << 1) | (chanB);
     prevState_ = currState_;
-
-    //X2 encoding uses interrupts on only channel A.
-    //X4 encoding uses interrupts on      channel A,
-    //and on channel B.
+ 
     channelA_.rise(this, &QEI::encode);
     channelA_.fall(this, &QEI::encode);
-
-    //If we're using X4 encoding, then attach interrupts to channel B too.
+ 
+ 
     if (encoding == X4_ENCODING) {
         channelB_.rise(this, &QEI::encode);
         channelB_.fall(this, &QEI::encode);
     }
-    //Index is optional.
     if (index !=  NC) {
         index_.rise(this, &QEI::index);
     }
-
+ 
 }
-
+ 
 void QEI::reset(void) {
-
+ 
     pulses_      = 0;
     revolutions_ = 0;
-
+    round_rev = 0;
+    sumangle = angle_ =0;
 }
-
+void QEI::set(int pul , int rev) {
+ 
+    pulses_      = pul;
+    revolutions_ = rev;
+ 
+}
 int QEI::getCurrentState(void) {
-
+ 
     return currState_;
-
+ 
 }
-
+ 
 int QEI::getPulses(void) {
-
+ 
     return pulses_;
-
+ 
+}
+ 
+int QEI::getRevolutions(void) {
+ 
+    return revolutions_;
+ 
 }
-
-int QEI::getRevolutions(void) {
-
-    return revolutions_;
-
+double QEI::getAngle()
+{
+    return angle_;
+}
+int QEI::getAng_rev()
+{
+    return round_rev;
+}
+double QEI::getSumangle()
+{
+    return sumangle;
 }
-
-// +-------------+
-// | X2 Encoding |
-// +-------------+
-//
-// When observing states two patterns will appear:
-//
-// Counter clockwise rotation:
-//
-// 10 -> 01 -> 10 -> 01 -> ...
-//
-// Clockwise rotation:
-//
-// 11 -> 00 -> 11 -> 00 -> ...
-//
-// We consider counter clockwise rotation to be "forward" and
-// counter clockwise to be "backward". Therefore pulse count will increase
-// during counter clockwise rotation and decrease during clockwise rotation.
-//
-// +-------------+
-// | X4 Encoding |
-// +-------------+
-//
-// There are four possible states for a quadrature encoder which correspond to
-// 2-bit gray code.
-//
-// A state change is only valid if of only one bit has changed.
-// A state change is invalid if both bits have changed.
-//
-// Clockwise Rotation ->
-//
-//    00 01 11 10 00
-//
-// <- Counter Clockwise Rotation
-//
-// If we observe any valid state changes going from left to right, we have
-// moved one pulse clockwise [we will consider this "backward" or "negative"].
-//
-// If we observe any valid state changes going from right to left we have
-// moved one pulse counter clockwise [we will consider this "forward" or
-// "positive"].
-//
-// We might enter an invalid state for a number of reasons which are hard to
-// predict - if this is the case, it is generally safe to ignore it, update
-// the state and carry on, with the error correcting itself shortly after.
+ 
+double QEI::getRPM()
+{
+    static double prev_angle;
+        Mper.stop();
+        
+        RPM = (sumangle - prev_angle) / Mper.read() * 60.0 / 360;
+        Mper.reset();
+        Mper.start();
+        prev_angle = sumangle;        
+    return RPM;
+}
+double QEI::getRPS()
+{
+    static double prev_angle;
+        Rper.stop();
+        
+        RPS = (sumangle - prev_angle) / Rper.read() / 360;
+        Rper.reset();
+        Rper.start();
+        prev_angle = sumangle;  
+    return RPS;
+}
+double QEI::getRPMS()
+{    static double prev_angle;
+        MSper.stop();
+        
+        RPMS = (sumangle - prev_angle) / (double)MSper.read_ms() / 360;
+        MSper.reset();
+        MSper.start();
+        prev_angle = sumangle;  
+    return RPMS;
+}
+double QEI::getRPUS()
+{    static double prev_angle;
+        USper.stop();
+        
+        RPUS = (sumangle - prev_angle) / (double)USper.read_us() / 360;
+        USper.reset();
+        USper.start();
+        prev_angle = sumangle;  
+    return RPUS;
+}
 void QEI::encode(void) {
-
+ 
     int change = 0;
     int chanA  = channelA_.read();
     int chanB  = channelB_.read();
-
-    //2-bit state.
+ 
     currState_ = (chanA << 1) | (chanB);
-
+    
     if (encoding_ == X2_ENCODING) {
-
-        //11->00->11->00 is counter clockwise rotation or "forward".
+ 
         if ((prevState_ == 0x3 && currState_ == 0x0) ||
                 (prevState_ == 0x0 && currState_ == 0x3)) {
-
+ 
             pulses_++;
-
+            angle_pulses++;
+ 
         }
-        //10->01->10->01 is clockwise rotation or "backward".
         else if ((prevState_ == 0x2 && currState_ == 0x1) ||
                  (prevState_ == 0x1 && currState_ == 0x2)) {
-
+ 
             pulses_--;
-
+            angle_pulses--;
+ 
         }
-
+ 
     } else if (encoding_ == X4_ENCODING) {
-
-        //Entered a new valid state.
+ 
         if (((currState_ ^ prevState_) != INVALID) && (currState_ != prevState_)) {
-            //2 bit state. Right hand bit of prev XOR left hand bit of current
-            //gives 0 if clockwise rotation and 1 if counter clockwise rotation.
             change = (prevState_ & PREV_MASK) ^ ((currState_ & CURR_MASK) >> 1);
-
+ 
             if (change == 0) {
                 change = -1;
             }
-
+ 
             pulses_ -= change;
+            angle_pulses -= change;
         }
-
+ 
     }
-
+    angle_ = angle_pulses*360/((double)pulsesPerRev_*4);
+    sumangle = pulses_*360/((double)pulsesPerRev_*4);
+    if(angle_>=360)
+    {
+        angle_pulses = angle_ = 0;
+        round_rev++;
+    }
+    else if(angle_<=-360)
+    {
+        angle_pulses = angle_ = 0;
+        round_rev--;
+    }
     prevState_ = currState_;
-
 }
-
+ 
 void QEI::index(void) {
-
+ 
     revolutions_++;
-
+ 
 }
+ 
+ 
+            
\ No newline at end of file