main.cpp

00001 #include "mbed.h"
00002 
00003 #include "string.h"
00004 #include <stdio.h>
00005 #include <ctype.h>
00006 
00007 #define RED_DONE 1
00008 #define YELLOW_DONE 2
00009 
00010 //Delays in ms
00011 #define TUNIT 250
00012 #define TDOT  TUNIT
00013 #define TDASH (3*TUNIT)
00014 #define TGAP TUNIT
00015 #define TLETTER (3*TUNIT)
00016 #define TWORD (7*TUNIT)
00017 
00018 //Size of the morse character buffer
00019 #define BUFFERSIZE 100
00020 
00021 
00022 /* 
00023 **** Morse Code ***
00024 
00025 .               1 unit
00026 -               3 units
00027 inter-space     1 unit
00028 
00029 between letters 3 units
00030 between words   7 units
00031 */
00032 
00033 //Morse code
00034 const char* const morseAlpha[] = {
00035     ".-",   //A
00036     "-...", //B
00037     "-.-.", //C
00038     "-..",  //D
00039     ".",    //E
00040     "..-.", //F
00041     "--.",  //G
00042     "....", //H
00043     "..",   //I
00044     ".---", //J
00045     "-.-",  //K
00046     ".-..", //L
00047     "--",   //M
00048     "-.",   //N
00049     "---",  //O
00050     ".--.", //P
00051     "--.-", //Q
00052     ".-.",  //R
00053     "...",  //S
00054     "-",    //T
00055     "..-",  //U
00056     "...-", //V
00057     ".--",  //W
00058     "-..-", //X
00059     "-.--", //Y
00060     "--.."  //Z
00061 };
00062 
00063 const char* const morseNumeric[] = {
00064     "-----",    //0
00065     ".----",    //1
00066     "..---",    //2
00067     "...--",    //3
00068     "....-",    //4
00069     ".....",    //5
00070     "-....",    //6
00071     "--...",    //7
00072     "---..",    //8
00073     "----."     //9    
00074 };
00075 
00076 //Digital outputs
00077 DigitalOut onBoardLED(LED1);
00078 DigitalOut redLED(D7);
00079 DigitalOut yellowLED(D6);
00080 DigitalOut greenLED(D5);
00081 
00082 //Serial Interface
00083 Serial pc(USBTX, USBRX);
00084 
00085 //Digital inputs
00086 DigitalIn  onBoardSwitch(USER_BUTTON);
00087 DigitalIn  SW1(D4);
00088 DigitalIn  SW2(D3);
00089 
00090 //Thread ID for the Main function (CMSIS API)
00091 osThreadId tidMain;
00092 
00093 //Thread sychronisation primatives
00094 Semaphore *spaceAvailable;
00095 Semaphore *samplesInBuffer;
00096 Mutex *bufferLock;
00097 
00098 //Output buffer
00099 char buffer[BUFFERSIZE];
00100 unsigned int newestIndex = BUFFERSIZE-1;    //First time it is incremented, it will be 0
00101 unsigned int oldestIndex = BUFFERSIZE-1;          
00102 
00103 
00104 //Producer
00105 void addCharacterToQueue(const char c)
00106 {    
00107     //Is there space?
00108     int32_t Nspaces = spaceAvailable->wait();
00109              
00110     //Ok, there is space - take the lock
00111     bufferLock->lock();
00112     redLED = 1;       
00113         
00114     //Update buffer
00115     newestIndex = (newestIndex+1) % BUFFERSIZE;  
00116     buffer[newestIndex] = c;
00117     pc.printf("\tAdded ASCII Character: %2Xh (%c) to buffer, %d spaces available\n", c, c, Nspaces-1);
00118     
00119     //Release lock
00120     bufferLock->unlock();
00121     redLED = 0;
00122     
00123     //Signal that a sample has been added
00124     samplesInBuffer->release();
00125 }
00126 
00127 //Consumer
00128 char takeCharacterFromQueue()
00129 {    
00130     //Are thre any samples in the buffer
00131     int32_t Nsamples = samplesInBuffer->wait();
00132         
00133     //Ok, there are samples - take the lock
00134     bufferLock->lock();   
00135     yellowLED = 1;
00136     
00137     //Update buffer - remove oldest
00138     oldestIndex = (oldestIndex+1) % BUFFERSIZE;
00139     char cc = buffer[oldestIndex];
00140     pc.printf("\t\tTaking ASCII Character: %2Xh (%c) from buffer, %d bytes remaining\n", cc, cc, Nsamples-1);
00141     
00142     //Release lock
00143     bufferLock->unlock();
00144     yellowLED = 0;
00145     
00146     //Signal there is space in the buffer
00147     spaceAvailable->release();
00148     
00149     //return a copy of the result
00150     return cc;
00151 }
00152 
00153 void morseGenerator() 
00154 {
00155     while (true) {
00156         
00157         //Are there samples available?
00158         char nextChar = takeCharacterFromQueue();  
00159         nextChar = tolower(nextChar);
00160         
00161         //Look up morse code
00162         
00163         //Space between words - assumes only one
00164         if (nextChar == ' ') {
00165             Thread::wait(TWORD-TLETTER);
00166             continue;   
00167         }
00168         
00169         //Number?
00170         const char *nextString;
00171         if ((nextChar >= '0') && (nextChar <= '9')) {
00172             nextString = morseNumeric[nextChar - '0'];   
00173         }
00174         //Character?
00175         else if ((nextChar >='a') && (nextChar <= 'z')) {
00176             nextString = morseAlpha[nextChar - 'a'];   
00177         } else {
00178             //Invalid
00179             continue;   
00180         }
00181         
00182         //Flash morse for this letter
00183         for (unsigned int n=0; n<strlen(nextString); n++) {
00184             char symb = nextString[n];
00185             greenLED = 1;
00186             switch (symb) {
00187                 case '.':
00188                     Thread::wait(TDOT);
00189                     break;
00190                 case '-':
00191                     Thread::wait(TDASH);
00192                     break;
00193                 default:
00194                     break;  
00195             }
00196             greenLED = 0;
00197             
00198             //A gap between symbols
00199             Thread::wait(TGAP);    
00200         } 
00201         
00202         //Gap between letters
00203         Thread::wait(TLETTER-TGAP);
00204         
00205     }      
00206 }
00207 
00208 //Main thread
00209 int main() {
00210     Thread writer;
00211     
00212     redLED    = 0;
00213     yellowLED = 0;
00214     greenLED  = 0;
00215         
00216     //Semaphores
00217     bufferLock = new Mutex();
00218     spaceAvailable = new Semaphore(BUFFERSIZE);
00219     samplesInBuffer = new Semaphore(0);
00220         
00221     
00222     //Main thread ID
00223     tidMain = Thread::gettid();  
00224     
00225     
00226     //Thread for outputting mors
00227     writer.start(morseGenerator);
00228     
00229     pc.printf("Type characters to send\n");
00230     while (true) {
00231         //Read keyboard (serial port)
00232         char c = pc.getc();
00233         addCharacterToQueue(c);
00234     }
00235 
00236 }
00237 
00238