SerialFlow.cpp

00001 /* mbed Serial Flow Library
00002  * Copyright (c) 2012 Oleg Evsegneev
00003  * Released under the MIT License: http://mbed.org/license/mit
00004  */
00005  
00006 #include "SerialFlow.h"
00007 #include "mbed.h"
00008 
00009 #ifdef USE_MODSERIAL
00010 SerialFlow::SerialFlow(PinName tx, PinName rx): _serial(tx, rx, TX_BUFFER_SIZE, RX_BUFFER_SIZE) {
00011 #else
00012 SerialFlow::SerialFlow(PinName tx, PinName rx): _serial(tx, rx) {
00013 #endif
00014     _escape = 0;
00015     _collecting = 0;
00016 }
00017 
00018 void SerialFlow::baud(int baud_rate) {
00019     _serial.baud(baud_rate);
00020 }
00021 
00022 void SerialFlow::setPacketFormat(DataFormat p_format, char v_length, char p_size) {
00023     _p_format = p_format;
00024     _v_length = v_length;
00025     _p_size = p_size;
00026     _vs_idx = 0;
00027     _vr_idx = 0;
00028 }
00029 
00030 void SerialFlow::setPacketValue(short value) {
00031     if( _vs_idx < _p_size ){
00032         _vs[_vs_idx++] = value;
00033     }
00034 }
00035 
00036 bool SerialFlow::sendPacket() {
00037     char v;
00038     if( !_serial.writeable() ){
00039         _vs_idx = 0;
00040         return 0;
00041     }
00042         
00043     _serial.putc( 0x12 );
00044     for( char i=0; i<_vs_idx; i++ ){
00045         // low byte
00046         v = _vs[i] & 0xFF;
00047         if( v==0x12 || v==0x13 || v==0x7D || v==0x10 )
00048             _serial.putc( 0x7D );
00049         _serial.putc( v );
00050 
00051         // high byte
00052         v = (_vs[i]>>8) & 0xFF;
00053         if( v==0x12 || v==0x13 || v==0x7D || v==0x10 )
00054             _serial.putc( 0x7D );
00055         _serial.putc( v );
00056             
00057         // separate values
00058         if( i<_vs_idx-1 )
00059             _serial.putc(0x10);
00060     }
00061         
00062     _serial.putc( 0x13 );
00063     _vs_idx = 0;
00064     return 1;
00065 }
00066 
00067 bool SerialFlow::receivePacket() {
00068     char c;
00069     while( _serial.readable() ){
00070         c = _serial.getc();
00071         if( _collecting )
00072             if( _escape ){
00073                 _vr_val[_cr_idx++] = c;
00074                 _escape = 0;
00075             }
00076             // escape
00077             else if( c == 0x7D ){
00078                 _escape = 1;
00079             }
00080             // value separator
00081             else if( c == 0x10 ){
00082                 _vr[_vr_idx++] = _vr_val[0] | (_vr_val[1] << 8);
00083                 _cr_idx = 0;
00084             }    
00085             // end
00086             else if( c == 0x13 ){
00087                 _vr[_vr_idx++] = _vr_val[0] | (_vr_val[1] << 8);
00088                 _collecting = 0;
00089                 return 1;
00090             }    
00091             else{
00092                 _vr_val[_cr_idx++] = c;
00093             }    
00094         // begin
00095         else if( c == 0x12 ){
00096             _collecting = 1;
00097             _cr_idx = 0;
00098             _vr_idx = 0;
00099         }    
00100     }
00101     return 0;
00102 }
00103 
00104 short SerialFlow::getPacket( char idx ) {
00105     return _vr[idx];
00106 }