Diff: QEI.h

Revision:

1:5f28ceec8280

Parent:

0:5c2ad81551aa

--- a/QEI.h	Thu Sep 02 16:48:55 2010 +0000
+++ b/QEI.h	Wed May 04 18:47:39 2016 +0000
@@ -1,158 +1,24 @@
-/**
- * @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.
- */
 
 #ifndef QEI_H
 #define QEI_H
 
-/**
- * Includes
- */
 #include "mbed.h"
 
-/**
- * Defines
- */
-#define PREV_MASK 0x1 //Mask for the previous state in determining direction
-//of rotation.
-#define CURR_MASK 0x2 //Mask for the current state in determining direction
-//of rotation.
+#define PREV_MASK 0x1 //Mask for the previous state in determining direction of rotation.
+#define CURR_MASK 0x2 //Mask for the current state in determining direction of rotation.
 #define INVALID   0x3 //XORing two states where both bits have changed.
 
-/**
- * Quadrature Encoder Interface.
- */
+
 class QEI {
 
 public:
 
-    typedef enum Encoding {
-
-        X2_ENCODING,
+    typedef enum Encoding 
+    { 
+        X2_ENCODING, 
         X4_ENCODING
-
-    } Encoding;
+                } 
+        Encoding;
 
     /**
      * Constructor.