Chris Taylor / SignalGenerator

Provides a simple way to generate complex square wave signals on any available pin. In addition the SignalGenerator can generate a carrier wave which is useful when generating IR signals to control electronic devices like a TV etc. The signal generation can be carried out either synchronously or asynchronously. In the case of synchronous signal generation all interrupts can optionally be disabled to improve timing accuracy.

Diff: SignalGenerator.h

Revision:
4:64d2d834341b
Parent:
3:f30dcc6e8e70
--- a/SignalGenerator.h	Sat Sep 13 21:40:16 2014 +0000
+++ b/SignalGenerator.h	Sun Sep 14 05:36:57 2014 +0000
@@ -12,13 +12,17 @@
         /** Create a SignalGenerator tied to the specified pin. */
         SignalGenerator(PinName pin);
         
+        /** Clean up the SignalGenerator data. */
+        ~SignalGenerator();
+        
         /** Set the state of the pin associated with the SignalGenerator. */  
         void set(bool pinState);
         
-        /** Set parameter and generate the corresponding signal on the pin associated with the SignalGenerator. 
+        /** Generates the square wave signal on the pin associated with the SignalGenerator. 
          * @param initialState Defines the initial state of the signal pin
          * @param timingBuffer Specificies the wime periods in microseconds before the signal pin changes state
          * @param bufferCount The count of transition times passed in the timingBuffer
+         * @param disableInterrupts If true disables interrupts during the generation of the signal
          * @param lastStateHoldTime The time in microseconds that the last state is held
          * @param carrierFrequency The carrier frequency in Hz
         */  
@@ -26,10 +30,33 @@
             bool initialState, 
             uint32_t timingBuffer[], 
             uint16_t bufferCount, 
+            bool disableInterrupts,
             uint32_t lastStateHoldTime = 0, 
             int32_t carrierFrequency = -1);
+        
+        /** Asynchronously generates the square wave signal on the pin associated with the SignalGenerator. 
+         * @param initialState Defines the initial state of the signal pin
+         * @param timingBuffer Specificies the wime periods in microseconds before the signal pin changes state
+         * @param bufferCount The count of transition times passed in the timingBuffer
+         * @param repeat If true the signal generation will wrap around to the begining of the timingBuffer after each iteration through the buffer completes.
+         * @note To stop the asynchronous signal you can call any of the non-async set commands to set the pin to a final state.
+        */    
+        void setAsync(
+            bool initialState, 
+            uint32_t timingBuffer[], 
+            uint16_t bufferCount, 
+            bool repeat);
             
     private:
-        DigitalOut  _pin;    
+        void asyncStep();
+        void stopAsync();
+            
+    private:
+        DigitalOut  _pin; 
+        Timeout     *_pTicker; 
+        uint32_t    *_pInternalTimingBuffer;
+        uint16_t    _bufferCount;
+        uint16_t    _bufferIndex;
+        bool        _repeat;
 };
 #endif //__SIGNALGENERATOR_H__
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