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<h1>encoder.c</h1><a href="encoder_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 <span class="comment">/*! \file encoder.c \brief Quadrature Encoder reader/driver. */</span>
00002 <span class="comment">//*****************************************************************************</span>
00003 <span class="comment">//</span>
00004 <span class="comment">// File Name : 'encoder.c'</span>
00005 <span class="comment">// Title : Quadrature Encoder reader/driver</span>
00006 <span class="comment">// Author : Pascal Stang - Copyright (C) 2003-2004</span>
00007 <span class="comment">// Created : 2003.01.26</span>
00008 <span class="comment">// Revised : 2004.06.25</span>
00009 <span class="comment">// Version : 0.3</span>
00010 <span class="comment">// Target MCU : Atmel AVR Series</span>
00011 <span class="comment">// Editor Tabs : 4</span>
00012 <span class="comment">//</span>
00013 <span class="comment">// NOTE: This code is currently below version 1.0, and therefore is considered</span>
00014 <span class="comment">// to be lacking in some functionality or documentation, or may not be fully</span>
00015 <span class="comment">// tested. Nonetheless, you can expect most functions to work.</span>
00016 <span class="comment">//</span>
00017 <span class="comment">// This code is distributed under the GNU Public License</span>
00018 <span class="comment">// which can be found at http://www.gnu.org/licenses/gpl.txt</span>
00019 <span class="comment">//</span>
00020 <span class="comment">//*****************************************************************************</span>
00021
00022 <span class="preprocessor">#include <avr/io.h></span>
00023 <span class="preprocessor">#include <avr/interrupt.h></span>
00024
00025 <span class="preprocessor">#include "<a class="code" href="global_8h.html">global.h</a>"</span>
00026 <span class="preprocessor">#include "<a class="code" href="encoder_8h.html">encoder.h</a>"</span>
00027
00028 <span class="comment">// Program ROM constants</span>
00029
00030 <span class="comment">// Global variables</span>
00031 <span class="keyword">volatile</span> <a class="code" href="structstruct__EncoderState.html">EncoderStateType</a> EncoderState[NUM_ENCODERS];
00032
00033 <span class="comment">// Functions</span>
00034
00035 <span class="comment">// encoderInit() initializes hardware and encoder position readings</span>
00036 <span class="comment">// Run this init routine once before using any other encoder functions.</span>
<a name="l00037"></a><a class="code" href="encoder_8h.html#a2">00037</a> <span class="keywordtype">void</span> <a class="code" href="encoder_8c.html#a1">encoderInit</a>(<span class="keywordtype">void</span>)
00038 {
00039 u08 i;
00040
00041 <span class="comment">// initialize/clear encoder data</span>
00042 <span class="keywordflow">for</span>(i=0; i<NUM_ENCODERS; i++)
00043 {
00044 EncoderState[i].<a class="code" href="structstruct__EncoderState.html#o0">position</a> = 0;
00045 <span class="comment">//EncoderState[i].velocity = 0; // NOT CURRENTLY USED</span>
00046 }
00047
00048 <span class="comment">// configure direction and interrupt I/O pins:</span>
00049 <span class="comment">// - for input</span>
00050 <span class="comment">// - apply pullup resistors</span>
00051 <span class="comment">// - any-edge interrupt triggering</span>
00052 <span class="comment">// - enable interrupt</span>
00053
00054 <span class="preprocessor"> #ifdef ENC0_SIGNAL</span>
00055 <span class="preprocessor"></span> <span class="comment">// set interrupt pins to input and apply pullup resistor</span>
00056 cbi(ENC0_PHASEA_DDR, ENC0_PHASEA_PIN);
00057 sbi(ENC0_PHASEA_PORT, ENC0_PHASEA_PIN);
00058 <span class="comment">// set encoder direction pin for input and apply pullup resistor</span>
00059 cbi(ENC0_PHASEB_DDR, ENC0_PHASEB_PIN);
00060 sbi(ENC0_PHASEB_PORT, ENC0_PHASEB_PIN);
00061 <span class="comment">// configure interrupts for any-edge triggering</span>
00062 sbi(ENC0_ICR, ENC0_ISCX0);
00063 cbi(ENC0_ICR, ENC0_ISCX1);
00064 <span class="comment">// enable interrupts</span>
00065 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, ENC0_INT); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00066 <span class="preprocessor"> #endif</span>
00067 <span class="preprocessor"></span><span class="preprocessor"> #ifdef ENC1_SIGNAL</span>
00068 <span class="preprocessor"></span> <span class="comment">// set interrupt pins to input and apply pullup resistor</span>
00069 cbi(ENC1_PHASEA_DDR, ENC1_PHASEA_PIN);
00070 sbi(ENC1_PHASEA_PORT, ENC1_PHASEA_PIN);
00071 <span class="comment">// set encoder direction pin for input and apply pullup resistor</span>
00072 cbi(ENC1_PHASEB_DDR, ENC1_PHASEB_PIN);
00073 sbi(ENC1_PHASEB_PORT, ENC1_PHASEB_PIN);
00074 <span class="comment">// configure interrupts for any-edge triggering</span>
00075 sbi(ENC1_ICR, ENC1_ISCX0);
00076 cbi(ENC1_ICR, ENC1_ISCX1);
00077 <span class="comment">// enable interrupts</span>
00078 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, ENC1_INT); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00079 <span class="preprocessor"> #endif</span>
00080 <span class="preprocessor"></span><span class="preprocessor"> #ifdef ENC2_SIGNAL</span>
00081 <span class="preprocessor"></span> <span class="comment">// set interrupt pins to input and apply pullup resistor</span>
00082 cbi(ENC2_PHASEA_DDR, ENC2_PHASEA_PIN);
00083 sbi(ENC2_PHASEA_PORT, ENC2_PHASEA_PIN);
00084 <span class="comment">// set encoder direction pin for input and apply pullup resistor</span>
00085 cbi(ENC2_PHASEB_DDR, ENC2_PHASEB_PIN);
00086 sbi(ENC2_PHASEB_PORT, ENC2_PHASEB_PIN);
00087 <span class="comment">// configure interrupts for any-edge triggering</span>
00088 sbi(ENC2_ICR, ENC2_ISCX0);
00089 cbi(ENC2_ICR, ENC2_ISCX1);
00090 <span class="comment">// enable interrupts</span>
00091 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, ENC2_INT); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00092 <span class="preprocessor"> #endif</span>
00093 <span class="preprocessor"></span><span class="preprocessor"> #ifdef ENC3_SIGNAL</span>
00094 <span class="preprocessor"></span> <span class="comment">// set interrupt pins to input and apply pullup resistor</span>
00095 cbi(ENC3_PHASEA_DDR, ENC3_PHASEA_PIN);
00096 sbi(ENC3_PHASEA_PORT, ENC3_PHASEA_PIN);
00097 <span class="comment">// set encoder direction pin for input and apply pullup resistor</span>
00098 cbi(ENC3_PHASEB_DDR, ENC3_PHASEB_PIN);
00099 sbi(ENC3_PHASEB_PORT, ENC3_PHASEB_PIN);
00100 <span class="comment">// configure interrupts for any-edge triggering</span>
00101 sbi(ENC3_ICR, ENC3_ISCX0);
00102 cbi(ENC3_ICR, ENC3_ISCX1);
00103 <span class="comment">// enable interrupts</span>
00104 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, ENC3_INT); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00105 <span class="preprocessor"> #endif</span>
00106 <span class="preprocessor"></span>
00107 <span class="comment">// enable global interrupts</span>
00108 sei();
00109 }
00110
00111 <span class="comment">// encoderOff() disables hardware and stops encoder position updates</span>
<a name="l00112"></a><a class="code" href="encoder_8h.html#a3">00112</a> <span class="keywordtype">void</span> <a class="code" href="encoder_8c.html#a2">encoderOff</a>(<span class="keywordtype">void</span>)
00113 {
00114 <span class="comment">// disable encoder interrupts</span>
00115 <span class="preprocessor"> #ifdef ENC0_SIGNAL</span>
00116 <span class="preprocessor"></span> <span class="comment">// disable interrupts</span>
00117 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, INT0); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00118 <span class="preprocessor"> #endif</span>
00119 <span class="preprocessor"></span><span class="preprocessor"> #ifdef ENC1_SIGNAL</span>
00120 <span class="preprocessor"></span> <span class="comment">// disable interrupts</span>
00121 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, INT1); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00122 <span class="preprocessor"> #endif</span>
00123 <span class="preprocessor"></span><span class="preprocessor"> #ifdef ENC2_SIGNAL</span>
00124 <span class="preprocessor"></span> <span class="comment">// disable interrupts</span>
00125 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, INT2); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00126 <span class="preprocessor"> #endif</span>
00127 <span class="preprocessor"></span><span class="preprocessor"> #ifdef ENC3_SIGNAL</span>
00128 <span class="preprocessor"></span> <span class="comment">// disable interrupts</span>
00129 sbi(<a class="code" href="encoder_8h.html#a0">IMSK</a>, INT3); <span class="comment">// ISMK is auto-defined in encoder.h</span>
00130 <span class="preprocessor"> #endif</span>
00131 <span class="preprocessor"></span>}
00132
00133 <span class="comment">// encoderGetPosition() reads the current position of the encoder </span>
<a name="l00134"></a><a class="code" href="encoder_8h.html#a4">00134</a> s32 <a class="code" href="encoder_8c.html#a3">encoderGetPosition</a>(u08 encoderNum)
00135 {
00136 <span class="comment">// sanity check</span>
00137 <span class="keywordflow">if</span>(encoderNum < NUM_ENCODERS)
00138 <span class="keywordflow">return</span> EncoderState[encoderNum].<a class="code" href="structstruct__EncoderState.html#o0">position</a>;
00139 <span class="keywordflow">else</span>
00140 <span class="keywordflow">return</span> 0;
00141 }
00142
00143 <span class="comment">// encoderSetPosition() sets the current position of the encoder</span>
<a name="l00144"></a><a class="code" href="encoder_8h.html#a5">00144</a> <span class="keywordtype">void</span> <a class="code" href="encoder_8c.html#a4">encoderSetPosition</a>(u08 encoderNum, s32 position)
00145 {
00146 <span class="comment">// sanity check</span>
00147 <span class="keywordflow">if</span>(encoderNum < NUM_ENCODERS)
00148 EncoderState[encoderNum].<a class="code" href="structstruct__EncoderState.html#o0">position</a> = position;
00149 <span class="comment">// else do nothing</span>
00150 }
00151
00152 <span class="preprocessor">#ifdef ENC0_SIGNAL</span>
00153 <span class="preprocessor"></span><span class="comment">//! Encoder 0 interrupt handler</span>
00154 <span class="comment"></span><a class="code" href="a2d_8c.html#a10">SIGNAL</a>(ENC0_SIGNAL)
00155 {
00156 <span class="comment">// encoder has generated a pulse</span>
00157 <span class="comment">// check the relative phase of the input channels</span>
00158 <span class="comment">// and update position accordingly</span>
00159 <span class="keywordflow">if</span>( ((inb(ENC0_PHASEA_PORTIN) & (1<<ENC0_PHASEA_PIN)) == 0) ^
00160 ((inb(ENC0_PHASEB_PORTIN) & (1<<ENC0_PHASEB_PIN)) == 0) )
00161 {
00162 EncoderState[0].<a class="code" href="structstruct__EncoderState.html#o0">position</a>++;
00163 }
00164 <span class="keywordflow">else</span>
00165 {
00166 EncoderState[0].<a class="code" href="structstruct__EncoderState.html#o0">position</a>--;
00167 }
00168 }
00169 <span class="preprocessor">#endif</span>
00170 <span class="preprocessor"></span>
00171 <span class="preprocessor">#ifdef ENC1_SIGNAL</span>
00172 <span class="preprocessor"></span><span class="comment">//! Encoder 1 interrupt handler</span>
00173 <span class="comment"></span><a class="code" href="a2d_8c.html#a10">SIGNAL</a>(ENC1_SIGNAL)
00174 {
00175 <span class="comment">// encoder has generated a pulse</span>
00176 <span class="comment">// check the relative phase of the input channels</span>
00177 <span class="comment">// and update position accordingly</span>
00178 <span class="keywordflow">if</span>( ((inb(ENC1_PHASEA_PORTIN) & (1<<ENC1_PHASEA_PIN)) == 0) ^
00179 ((inb(ENC1_PHASEB_PORTIN) & (1<<ENC1_PHASEB_PIN)) == 0) )
00180 {
00181 EncoderState[1].<a class="code" href="structstruct__EncoderState.html#o0">position</a>++;
00182 }
00183 <span class="keywordflow">else</span>
00184 {
00185 EncoderState[1].<a class="code" href="structstruct__EncoderState.html#o0">position</a>--;
00186 }
00187 }
00188 <span class="preprocessor">#endif</span>
00189 <span class="preprocessor"></span>
00190 <span class="preprocessor">#ifdef ENC2_SIGNAL</span>
00191 <span class="preprocessor"></span><span class="comment">//! Encoder 2 interrupt handler</span>
00192 <span class="comment"></span><a class="code" href="a2d_8c.html#a10">SIGNAL</a>(ENC2_SIGNAL)
00193 {
00194 <span class="comment">// encoder has generated a pulse</span>
00195 <span class="comment">// check the relative phase of the input channels</span>
00196 <span class="comment">// and update position accordingly</span>
00197 <span class="keywordflow">if</span>( ((inb(ENC2_PHASEA_PORTIN) & (1<<ENC2_PHASEA_PIN)) == 0) ^
00198 ((inb(ENC2_PHASEB_PORTIN) & (1<<ENC2_PHASEB_PIN)) == 0) )
00199 {
00200 EncoderState[2].<a class="code" href="structstruct__EncoderState.html#o0">position</a>++;
00201 }
00202 <span class="keywordflow">else</span>
00203 {
00204 EncoderState[2].<a class="code" href="structstruct__EncoderState.html#o0">position</a>--;
00205 }
00206 }
00207 <span class="preprocessor">#endif</span>
00208 <span class="preprocessor"></span>
00209 <span class="preprocessor">#ifdef ENC3_SIGNAL</span>
00210 <span class="preprocessor"></span><span class="comment">//! Encoder 3 interrupt handler</span>
00211 <span class="comment"></span><a class="code" href="a2d_8c.html#a10">SIGNAL</a>(ENC3_SIGNAL)
00212 {
00213 <span class="comment">// encoder has generated a pulse</span>
00214 <span class="comment">// check the relative phase of the input channels</span>
00215 <span class="comment">// and update position accordingly</span>
00216 <span class="keywordflow">if</span>( ((inb(ENC3_PHASEA_PORTIN) & (1<<ENC3_PHASEA_PIN)) == 0) ^
00217 ((inb(ENC3_PHASEB_PORTIN) & (1<<ENC3_PHASEB_PIN)) == 0) )
00218 {
00219 EncoderState[3].<a class="code" href="structstruct__EncoderState.html#o0">position</a>++;
00220 }
00221 <span class="keywordflow">else</span>
00222 {
00223 EncoderState[3].<a class="code" href="structstruct__EncoderState.html#o0">position</a>--;
00224 }
00225 }
00226 <span class="preprocessor">#endif</span>
</pre></div><hr size="1"><address style="align: right;"><small>Generated on Sun Oct 29 03:41:06 2006 for Procyon AVRlib by
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