rs232.cpp

00001 #include "mbed.h"
00002 #include "rs232.h"
00003 
00004 
00005 
00006 //---------------------------------------
00007 // Hardware recources
00008 //---------------------------------------
00009 Serial      rs232(p13, p14);    // TXD, RXD
00010 Timeout     rs232Timeout;
00011 DigitalOut  rs232RTS(p12);      // RTS 
00012 DigitalIn   rs232CTS(p11);      // CTS
00013 
00014 
00015 //---------------------------------------
00016 // Prototypes
00017 //---------------------------------------
00018 static void RS232_reset( void );
00019 static void RS232_rxCallback( void );
00020 static void RS232_rxTimeout( void );
00021 
00022 
00023 //---------------------------------------
00024 // Internal variables
00025 //---------------------------------------
00026 static char RS232Buffer[RS232_BUFFER_LENGTH];
00027 static sRS232_handler RS232_handler;
00028 
00029 
00030 
00031 //---------------------------------------
00032 // External variables
00033 //---------------------------------------
00034 
00035 
00036 
00037 //---------------------------------------
00038 // Global Functions
00039 //---------------------------------------
00040 void RS232_init( void )
00041 {
00042     rs232RTS = 0;
00043     rs232.baud(RS232_BAUDRATE);
00044     rs232.format(RS232_BITS, Serial::None, RS232_STOPBIT );
00045     RS232_reset();
00046     rs232.attach( &RS232_rxCallback, Serial::RxIrq );      // call RS232_rx() on every RX interrupt
00047 }
00048 
00049 
00050 
00051 // Return 1: Sending was successfull
00052 // Return 0: Could not send data, eithter to many bytes or zero bytes
00053 int RS232_sendData( char *ptrData, int NumBytes )
00054 {
00055     int i;
00056     
00057     if( (NumBytes == 0) || (NumBytes >= RS232_BUFFER_LENGTH  )  )
00058     {
00059         return 0;
00060     }
00061     
00062     // Send data
00063     for( i = 0; i < NumBytes; i++ )
00064     {
00065         while( !rs232.writeable() );
00066         rs232.putc(*ptrData);
00067         ptrData++;
00068     }//for
00069 
00070     return 1;
00071 }
00072 
00073 
00074 // Return 1: New data available, get pointer to buffer and number of bytes to read
00075 // Return 0: No new data available
00076 int RS232_receiveData( char *& ptrData, int *ptrNumBytes )
00077 {    
00078     // Dummy operation to avoid compiler warning
00079     ptrData++;
00080 
00081     if( RS232_handler.mode != RS232_MODE_RX_READY )
00082     {    
00083         *ptrNumBytes = 0;
00084         return 0;
00085     }
00086 
00087     *ptrNumBytes = RS232_handler.bytesToRead;
00088     ptrData = &RS232Buffer[0];
00089         
00090     RS232_reset();
00091     return 1;    
00092 }
00093 
00094 
00095 
00096 void RS232_setRTS( int level)
00097 {
00098     if( level )
00099     {
00100         rs232RTS = 0;
00101     }
00102     else
00103     {
00104         rs232RTS = 1;
00105     }
00106 
00107 }
00108 
00109 
00110 int RS232_getCTS( void )
00111 {
00112     return rs232CTS;
00113 }
00114 
00115 
00116 //---------------------------------------
00117 // Internal Functions
00118 //---------------------------------------
00119 
00120 static void RS232_reset( void )
00121 {
00122    RS232_handler.ptrReadPositon = &RS232Buffer[0];
00123    RS232_handler.bytesToRead = 0;
00124    RS232_handler.mode = RS232_MODE_LISTEN;
00125 }
00126 
00127 
00128 // Function is called on RX interrupt
00129 void RS232_rxCallback( void )
00130 {
00131     char tempChar;
00132     
00133     tempChar = rs232.getc();
00134     
00135     if( (RS232_handler.mode != RS232_MODE_LISTEN) || (RS232_handler.bytesToRead >= RS232_BUFFER_LENGTH) )
00136     {
00137         return;
00138     }
00139 
00140     // Restart timeout timer
00141     rs232Timeout.attach_us( &RS232_rxTimeout, RS232_RX_TIMEOUT_US );
00142     // Save received byte
00143     *RS232_handler.ptrReadPositon = tempChar;
00144     RS232_handler.ptrReadPositon++;
00145     RS232_handler.bytesToRead++;    
00146 }
00147 
00148 
00149 void RS232_rxTimeout( void )
00150 {
00151     // Disable timeout
00152     rs232Timeout.detach();
00153     RS232_handler.mode = RS232_MODE_RX_READY;   // Transmission is ready
00154 }