blinker.cpp

00001 // blinker.cpp - send a morse pattern to LED1
00002 //
00003 // Function morse() is one way for running LED1 with a blinking sequence using
00004 // a busy wait, until the sequence is completed.
00005 //
00006 //    Blinker b;
00007 //    b.morse(" x xxx x    ");      send one time morse sequence, interval = 0.2
00008 //    b.morse(" x xxx x    ",0.5);  send one time morse sequence, interval = 0.5
00009 //
00010 // Function morse(o) got the additional feature to stop an ongoing timer based
00011 // blinking sequence.
00012 //    
00013 // The alternative is to setup an ever repeating blink sequence via LED1 using
00014 // function blink(), which is non waiting.
00015 //
00016 //    Blinker b;
00017 //    b.blink(" x xxx x    ");         repeating blink sequence, interval = 0.2
00018 //    b.blink(" x xxx x    ",0.5);     repeating blink sequence, interval = 0.5
00019 //    b.blink();                       stops blinking sequence
00020 //
00021 
00022 #include "bricks/target.h"
00023 #include "bricks/blinker.h"
00024 
00025 #ifndef LED_INVERTED
00026 #   define LED_ON  1
00027 #   define LED_OFF 0
00028 #else
00029 #   define LED_ON  0
00030 #   define LED_OFF 1
00031 #endif
00032 
00033 #ifndef BLINK_LED
00034 #   define BLINK_LED LED1
00035 #endif
00036 
00037    static DigitalOut led(BLINK_LED);    // being used for morse sequence
00038    static Ticker ticker;                // triggers periodic callbacks
00039    static const char *pointer = 0;      // 0 means morse activity disabled
00040    static const char *sequence = 0;     // next morse sequence for repeats
00041 
00042    void Blinker::morse(const char *pattern, double interval)
00043    {
00044        pointer = 0;                     // disable ticker based blinking
00045        sequence = 0;                    // set also empty sequence
00046        
00047        for (; *pattern; pattern++)
00048        {
00049           led = (*pattern == ' ') ? LED_OFF : LED_ON;
00050           wait(interval);               // busy waiting for interval time
00051        }
00052    }
00053           
00054 // callback for LED1 ticker controlled blinking   
00055            
00056    static void cbBlinker(void)         // blinker callback
00057    {
00058        if (pointer != 0)
00059       {
00060          if (*pointer == 0)
00061          {
00062             pointer = sequence;        // reset pointer to followup sequence
00063          }
00064         
00065          if (*pointer)
00066          {
00067             led = (*pointer++ == ' ') ? LED_OFF : LED_ON;
00068          }
00069       }
00070    }
00071    
00072    void Blinker::blink(const char *pattern, const char* next, double interval) 
00073    {
00074       pointer = 0;                      // stop current activities
00075       led = LED_OFF;                    // reset led with LED_OFF
00076       
00077       sequence = next;                  // init morse sequence   
00078          
00079       ticker.attach(cbBlinker,interval);// next LED state after every interval
00080       pointer = pattern;                // enable callback activty
00081    }  
00082 
00083    void Blinker::blink(const char *pattern, double interval)
00084    {
00085        blink(pattern,pattern,interval);
00086    }
00087    
00088