Diff: RC5Detect.h

Revision:

0:e3f62f54fa40

diff -r 000000000000 -r e3f62f54fa40 RC5Detect.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RC5Detect.h	Mon Feb 28 08:52:01 2011 +0000
@@ -0,0 +1,202 @@
+/*
+    Copyright (c) 2011 Pro-Serv
+ 
+    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.
+    
+    Usage and assumptions:
+    Based on TSOP 1738 IR device, Vcc to 5Volt, Gnd to Gnd, Out has pull-up of 10K
+    to Vcc and Out has diode (Cathode to Out) connected to pin (p16) (Anode to p16)
+    and pin (p16) has mode PullUp
+    
+    This will allow a "standard" RC5 device to be used to read it transmitted codes.
+    Still work in progress (in due time) to add newer rc6 devices
+    
+    Excellent source on RC5 protocol: http://www.ustr.net/infrared/infrared1.shtml
+ */
+
+#ifndef MBED_H
+#include "mbed.h"
+#endif
+
+#ifndef RC5_PIN_ASSTERED
+#define RC5_PIN_ASSTERED   1
+#endif
+
+#ifndef RC5_DELAY_PERIOD
+#define RC5_DELAY_PERIOD 4752
+#endif
+
+#ifndef RC5_INTERVAL_PERIOD
+#define RC5_INTERVAL_PERIOD 1728
+#endif
+
+#ifndef RC5_FINSISH_PERIOD
+#define RC5_FINISH_PERIOD 65000
+#endif
+
+#ifndef RC5_SAMPLE_COUNT
+#define RC5_SAMPLE_COUNT    14
+#endif
+
+namespace RC5 {
+
+/* RC5Detect adds a RC5 compatible data entry using InterruptIn & DigitalIn.
+ *
+ * This is done by sampling the specified pin at specific interrupt driven intervals
+   and sampling the actual pin level
+ */
+ 
+class RC5Detect {
+
+protected:
+    InterruptIn *_int;
+    DigitalIn   *_inp;
+    DigitalOut  *_out;     // out was added temporary for debugging
+    Ticker      *_ticker;
+    Timeout     *_delay;
+    Timeout     *_finish;
+    int         _stepCount;
+    int         _pulseCount;
+    int         _sampleInterval;
+    int         _sampleDelay;
+    int         _sampleFinish;
+    int         _assertValue;
+    int         _rc5Data;
+    int         _rc5Cmd;
+    int         _rc5Adr;
+    int         _rc5Ready;
+    
+    /* initialise class
+     *
+     * @param PinName p is a valid pin for InterruptIn/DigitalIn &
+     * @param PinMode m is a mode the InterruptIn/DigitalIn should use.
+     */
+    void init(PinName p, PinMode m) {
+        _sampleInterval          = RC5_INTERVAL_PERIOD;
+        _sampleDelay             = RC5_DELAY_PERIOD;
+        _sampleFinish            = RC5_FINISH_PERIOD;
+        _assertValue             = RC5_PIN_ASSTERED;
+        _int = new InterruptIn( p ); 
+        _inp = new DigitalIn( p );
+        //_out = new DigitalOut( x );     // out to be added temporary for debugging         
+        //_out->write(1);                 // same, set high level
+        _int->mode( m );
+        _inp->mode( m );
+        _stepCount = 0;    
+        _ticker = new Ticker;
+        _delay = new Timeout;
+        _finish = new Timeout;
+        _int->fall(this, &RC5Detect::isr_int);
+    }
+    
+public:
+
+    friend class Ticker;
+    friend class Timeout;
+
+    /* PinDetect constructor(s) & overloading */
+    RC5Detect() { error("Provide a valid PinName"); }
+
+    RC5Detect(PinName p) {
+        init( p, PullUp);
+    }
+
+    RC5Detect(PinName p, PinMode m) {
+        init( p, m );
+    }
+    
+    /* PinDetect destructor */    
+    ~RC5Detect() {
+        if ( _ticker ) delete( _ticker );
+        if ( _delay )  delete( _delay );
+        if ( _finish ) delete( _finish );
+        if ( _inp )    delete( _inp );
+        if ( _int )    delete( _int );
+    }
+
+    /* Set the sampling delay time in microseconds. */
+    void setDelaySample(int i = RC5_DELAY_PERIOD) { _sampleDelay = i; }
+    
+    /* Set the sampling interval time in microseconds. */
+    void setIntervalSample(int i = RC5_INTERVAL_PERIOD) { _sampleInterval = i; }
+    
+    /* Set the sampling finish time in microseconds. */
+    void setFinishSample(int i = RC5_FINISH_PERIOD) { _sampleFinish = i; }
+    
+    /* Set the value used as assert. */ /* not yet implemented */
+    void setAssertValue (int i = RC5_PIN_ASSTERED) { _assertValue = i & 1; }
+   
+    void mode(PinMode m) { _inp->mode( m ); }
+
+    bool getReadyState(void) { return _rc5Ready; }
+    
+    void setReadyState(int i) { _rc5Ready = i & 1; }
+    
+    int getRC5Address(void) { return _rc5Adr; }
+        
+    int getRC5Command(void) { return _rc5Cmd; }
+    
+protected:    
+    /* The interrupt service routines are: pin status, delay, interval and finish
+     * the pin status is intended to capture start of transmission */
+    void isr_int(void) {
+        if (_stepCount == 0) {                                  // first trigger event?
+            _stepCount++;
+            _rc5Ready = _rc5Cmd = _rc5Adr = 0;                  //
+            _delay->attach_us(this, &RC5Detect::isr_delay, _sampleDelay);
+            _finish->attach_us(this, &RC5Detect::isr_finish, _sampleFinish);
+        }
+        _pulseCount++;
+    }
+    
+    /* The delay is intended to hold of data sampling untill we get meaningfull bits */
+    void isr_delay() {
+        _ticker->attach_us( this, &RC5Detect::isr_interval, _sampleInterval );
+        _rc5Data = _inp->read() & 0x01;                         // add first bit of RC5
+        //_out->write(0);
+        //_out->write(1);
+    }
+    
+    /* The interval will sample all successive rc5 address and command bits */
+    void isr_interval() {
+        if (_stepCount == 10) {
+            _ticker->detach();                                  // sampling is done now !
+        }
+        _rc5Data = (_rc5Data << 1) + (_inp->read() & 0x01);     // shift partial and add next bit
+        _stepCount++;
+        //_out->write(0);
+        //_out->write(1);
+    }
+    
+    /* The finish is intended to do cleanup at end of frame and prepare for next frame */
+    void isr_finish() {
+        if ((_stepCount == 11) && (_pulseCount > 10)) {
+            _rc5Cmd = _rc5Data & 0x3f;                          // get command part of RC5
+            _rc5Adr = (_rc5Data >> 6) & 0x1f;                   // get address part of RC5
+            _rc5Ready = 1;
+        }
+        _pulseCount = _stepCount = _rc5Data = 0;                // init for next bit stream
+    }
+    
+};
+
+};                                                              // namespace RC5 ends.
+
+using namespace RC5;
+