main.cpp

00001 
00002 
00003 // My first code for the mbed.
00004 // Blinks "HELLO WORLD" out in Morse Code on LED1
00005 // Repeats forever
00006 //
00007 
00008 
00009 #include "mbed.h"
00010 
00011 #define WAIT_time 0.20      // about 5 wpm
00012 #define D() wait(WAIT_time)
00013 
00014 DigitalOut myled1(LED1);
00015 
00016 
00017 void send_dah();
00018 void send_dit();
00019 void send_space();
00020 void send_morse(char);
00021 void blink_out(char *ptr);
00022  
00023  
00024 char temp1;
00025 char rotate_char;
00026 char loops;
00027 char morse;
00028  
00029  
00030  
00031 // Offset 0x2C for ASCII to Morse code character pattern conversion
00032 // 0xFF means it is not a valid Morse code character
00033 
00034 // Characters are packed this way: Bits are rotated right until a "1". After that, "1" is a Dah, "0" is a Dit.
00035 // So, pad the LSBits with "0"s until the 8 bits represent a valid Morse Code charater.
00036 char mcode[100]=
00037 {
00038  0xCE,0xFF,0xAA,0xFF,
00039  0xFC,0xF4,0xE4,0xC4,0x84,0x04,0x0C,0x1C,0x3C,0x7C,     
00040  0xFF,0xFF,0xFF,0xFF,0xFF,0x32,0xFF,
00041  
00042  0xA0,0x18,0x58,0x30,0x40,0x48,0x70,0x08,0x20,0xE8,
00043  0xB0,0x28,0xE0,0x60,0xF0,0x68,0xB1,0x50,0x10,0xC0,
00044  0x90,0x81,0xD0,0x91,0xD8,0x31,
00045 
00046  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
00047 
00048  0xA0,0x18,0x58,0x30,0x40,0x48,0x70,0x08,0x20,0xE8,
00049  0xB0,0x28,0xE0,0x60,0xF0,0x68,0xB1,0x50,0x10,0xC0,
00050  0x90,0x81,0xD0,0x91,0xD8,0x31,
00051 };
00052 
00053 
00054 
00055 int main() {
00056 
00057     myled1 = 0;
00058     
00059     while(1) {
00060         blink_out("HELLO WORLD");
00061         send_space();
00062 
00063     }   
00064       
00065 }        
00066         
00067         
00068 void send_morse(char morse) {
00069         
00070     rotate_char = 0x01;            // set up mask bit 
00071     loops = 0x00;
00072     do {
00073         rotate_char <<= 1;
00074         loops++;
00075     }while ((morse & rotate_char) == 0);
00076         
00077     rotate_char <<= 1;
00078     loops++;
00079 
00080     do {
00081         if ((morse & rotate_char) == 0)       // if it is a zero, send a dit
00082             send_dit();
00083 
00084         else
00085             send_dah();
00086         
00087         rotate_char <<= 1;
00088         loops++;
00089     
00090     }while(loops < 8);                  // there are 8 bits 
00091 
00092 }
00093 
00094 
00095 
00096 void send_dit() {                      // dit is on one unit, off one unit 
00097 
00098     myled1 = 1;
00099     D();
00100     myled1 = 0;
00101     D();
00102    
00103 }
00104 
00105 
00106 void send_dah() {                      // dah is on 2 units, off 1 unit 
00107 
00108     myled1 = 1;
00109     D();
00110     D();
00111     myled1 = 0;
00112     D();
00113     
00114    
00115 }
00116 
00117 void send_space() {                   // space between words is 7 units 
00118 
00119     D();
00120     D();
00121     D();
00122     D();
00123     D();
00124     D();
00125     D();
00126 
00127 }    
00128 
00129 
00130 void blink_out(char *ptr) {
00131 
00132     while (*ptr)
00133         {temp1 = *ptr++;
00134        
00135         if (temp1 == 0x20)
00136                 {send_space();
00137                 temp1 = *ptr++;
00138                 };
00139             
00140         temp1-= 0x2C;                       
00141         morse = mcode[temp1];
00142         send_morse(morse);
00143         D();                                // 2 unit space
00144         D();
00145         }
00146 }
00147 
00148 
00149