SerialBuffered.cpp

00001 #include "mbed.h"
00002 #include "LPC.h"
00003 
00004 Serial pc2(USBTX, USBRX);
00005 
00006 SerialBuffered::SerialBuffered( size_t bufferSize, PinName tx, PinName rx ) : target(  tx,  rx ) {
00007     m_buffSize = 0;
00008     m_contentStart = 0;
00009     m_contentEnd = 0;
00010     m_timeout = 1.0;
00011     target.attach( this, &SerialBuffered::handleInterrupt );
00012     m_buff = (uint8_t *) malloc( bufferSize );
00013     if ( m_buff == NULL ) {
00014         pc2.printf("\n\rERROR: Failed to alloc serial buffer size of %d\r\n", (int) bufferSize );
00015     } else {
00016         m_buffSize = bufferSize;
00017     }
00018 }
00019 
00020 SerialBuffered::~SerialBuffered() {
00021     if ( m_buff )
00022         free( m_buff );
00023 }
00024 
00025 void SerialBuffered::InitUART(int baud) {  //Sets the baud rates
00026     pc2.baud(baud);
00027     target.baud(baud);
00028 }
00029 
00030 void SerialBuffered::TargetSendString(char * str) {  //Sends string to the board for console communication
00031     for (int i=0; i<strlen(str); i++) {
00032          target.putc(str[i]);
00033     }
00034 }
00035 
00036 void SerialBuffered::TargetSendStringAndCR(char * str) {  //Sends string to the board for console communication followed by the carriage return character
00037     for (int i=0; i<strlen(str); i++)
00038         target.putc(str[i]);
00039     target.putc(0x0D);
00040 }
00041 
00042 void SerialBuffered::setTimeout( float seconds ) {
00043     m_timeout = seconds;
00044 }
00045 
00046 size_t SerialBuffered::readBytes(char *bytes, size_t requested) {
00047     int i = 0;
00048     for (int a=0; a<m_buffSize; a++)
00049         bytes[a] = 0;
00050     for (; i<requested;) {
00051         int c = getc();
00052         if (c<0)
00053             break;
00054         bytes[i] = c;
00055         i++;
00056     }
00057     return i;
00058 }
00059 
00060 int SerialBuffered::getc() {
00061     m_timer.reset();
00062     m_timer.start();
00063     while (m_contentStart == m_contentEnd) {
00064         wait_ms(1);
00065         if (m_timeout>0 && m_timer.read()>m_timeout)
00066             return EOF;
00067     }
00068     m_timer.stop();
00069     uint8_t result = m_buff[m_contentStart++];
00070     m_contentStart =  m_contentStart % m_buffSize;
00071     return result;
00072 }
00073 
00074 int SerialBuffered::readable() {
00075     return m_contentStart != m_contentEnd ;
00076 }
00077 
00078 void SerialBuffered::handleInterrupt() {
00079     while (target.readable()) {
00080         if (m_contentStart == (m_contentEnd +1) % m_buffSize) {
00081             pc2.printf("\n\rERROR: Serial buffer overrun, data lost!\r\n" );
00082             exit(0);
00083         } else {
00084             m_buff[m_contentEnd++] = target.getc();
00085             m_contentEnd = m_contentEnd % m_buffSize;
00086         }
00087     }
00088 }