Richard Sewell
This is the SerialBuffered class, which wraps Serial and adds interrupt-powered buffered reading (so it will catch inbound data even when your app is busy doing something else) and simple read timeouts. There's a tiny demo app in there too.
SerialBuffered.cpp@0:b55ca3bb8017, 2009-11-18 (annotated)
- Committer:
- jarkman
- Date:
- Wed Nov 18 21:27:15 2009 +0000
- Revision:
- 0:b55ca3bb8017
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| jarkman | 0:b55ca3bb8017 | 1 | |
| jarkman | 0:b55ca3bb8017 | 2 | #include "mbed.h" |
| jarkman | 0:b55ca3bb8017 | 3 | #include "SerialBuffered.h" |
| jarkman | 0:b55ca3bb8017 | 4 | |
| jarkman | 0:b55ca3bb8017 | 5 | extern Serial loggerSerial; |
| jarkman | 0:b55ca3bb8017 | 6 | |
| jarkman | 0:b55ca3bb8017 | 7 | SerialBuffered::SerialBuffered( size_t bufferSize, PinName tx, PinName rx ) : Serial( tx, rx ) |
| jarkman | 0:b55ca3bb8017 | 8 | { |
| jarkman | 0:b55ca3bb8017 | 9 | m_buffSize = 0; |
| jarkman | 0:b55ca3bb8017 | 10 | m_contentStart = 0; |
| jarkman | 0:b55ca3bb8017 | 11 | m_contentEnd = 0; |
| jarkman | 0:b55ca3bb8017 | 12 | m_timeout = 1.0; |
| jarkman | 0:b55ca3bb8017 | 13 | |
| jarkman | 0:b55ca3bb8017 | 14 | |
| jarkman | 0:b55ca3bb8017 | 15 | attach( this, &SerialBuffered::handleInterrupt ); |
| jarkman | 0:b55ca3bb8017 | 16 | |
| jarkman | 0:b55ca3bb8017 | 17 | m_buff = (uint8_t *) malloc( bufferSize ); |
| jarkman | 0:b55ca3bb8017 | 18 | if( m_buff == NULL ) |
| jarkman | 0:b55ca3bb8017 | 19 | { |
| jarkman | 0:b55ca3bb8017 | 20 | //loggerSerial.printf("SerialBuffered - failed to alloc buffer size %d\r\n", (int) bufferSize ); |
| jarkman | 0:b55ca3bb8017 | 21 | } |
| jarkman | 0:b55ca3bb8017 | 22 | else |
| jarkman | 0:b55ca3bb8017 | 23 | { |
| jarkman | 0:b55ca3bb8017 | 24 | m_buffSize = bufferSize; |
| jarkman | 0:b55ca3bb8017 | 25 | } |
| jarkman | 0:b55ca3bb8017 | 26 | } |
| jarkman | 0:b55ca3bb8017 | 27 | |
| jarkman | 0:b55ca3bb8017 | 28 | |
| jarkman | 0:b55ca3bb8017 | 29 | SerialBuffered::~SerialBuffered() |
| jarkman | 0:b55ca3bb8017 | 30 | { |
| jarkman | 0:b55ca3bb8017 | 31 | if( m_buff ) |
| jarkman | 0:b55ca3bb8017 | 32 | free( m_buff ); |
| jarkman | 0:b55ca3bb8017 | 33 | } |
| jarkman | 0:b55ca3bb8017 | 34 | |
| jarkman | 0:b55ca3bb8017 | 35 | void SerialBuffered::setTimeout( float seconds ) |
| jarkman | 0:b55ca3bb8017 | 36 | { |
| jarkman | 0:b55ca3bb8017 | 37 | m_timeout = seconds; |
| jarkman | 0:b55ca3bb8017 | 38 | } |
| jarkman | 0:b55ca3bb8017 | 39 | |
| jarkman | 0:b55ca3bb8017 | 40 | size_t SerialBuffered::readBytes( uint8_t *bytes, size_t requested ) |
| jarkman | 0:b55ca3bb8017 | 41 | { |
| jarkman | 0:b55ca3bb8017 | 42 | int i = 0; |
| jarkman | 0:b55ca3bb8017 | 43 | |
| jarkman | 0:b55ca3bb8017 | 44 | for( ; i < requested; ) |
| jarkman | 0:b55ca3bb8017 | 45 | { |
| jarkman | 0:b55ca3bb8017 | 46 | int c = getc(); |
| jarkman | 0:b55ca3bb8017 | 47 | if( c < 0 ) |
| jarkman | 0:b55ca3bb8017 | 48 | break; |
| jarkman | 0:b55ca3bb8017 | 49 | bytes[i] = c; |
| jarkman | 0:b55ca3bb8017 | 50 | i++; |
| jarkman | 0:b55ca3bb8017 | 51 | } |
| jarkman | 0:b55ca3bb8017 | 52 | |
| jarkman | 0:b55ca3bb8017 | 53 | return i; |
| jarkman | 0:b55ca3bb8017 | 54 | |
| jarkman | 0:b55ca3bb8017 | 55 | } |
| jarkman | 0:b55ca3bb8017 | 56 | |
| jarkman | 0:b55ca3bb8017 | 57 | |
| jarkman | 0:b55ca3bb8017 | 58 | int SerialBuffered::getc() |
| jarkman | 0:b55ca3bb8017 | 59 | { |
| jarkman | 0:b55ca3bb8017 | 60 | m_timer.reset(); |
| jarkman | 0:b55ca3bb8017 | 61 | m_timer.start(); |
| jarkman | 0:b55ca3bb8017 | 62 | while( m_contentStart == m_contentEnd ) |
| jarkman | 0:b55ca3bb8017 | 63 | { |
| jarkman | 0:b55ca3bb8017 | 64 | |
| jarkman | 0:b55ca3bb8017 | 65 | |
| jarkman | 0:b55ca3bb8017 | 66 | wait_ms( 1 ); |
| jarkman | 0:b55ca3bb8017 | 67 | if( m_timeout > 0 && m_timer.read() > m_timeout ) |
| jarkman | 0:b55ca3bb8017 | 68 | return EOF; |
| jarkman | 0:b55ca3bb8017 | 69 | } |
| jarkman | 0:b55ca3bb8017 | 70 | |
| jarkman | 0:b55ca3bb8017 | 71 | m_timer.stop(); |
| jarkman | 0:b55ca3bb8017 | 72 | |
| jarkman | 0:b55ca3bb8017 | 73 | uint8_t result = m_buff[m_contentStart++]; |
| jarkman | 0:b55ca3bb8017 | 74 | m_contentStart = m_contentStart % m_buffSize; |
| jarkman | 0:b55ca3bb8017 | 75 | |
| jarkman | 0:b55ca3bb8017 | 76 | |
| jarkman | 0:b55ca3bb8017 | 77 | return result; |
| jarkman | 0:b55ca3bb8017 | 78 | } |
| jarkman | 0:b55ca3bb8017 | 79 | |
| jarkman | 0:b55ca3bb8017 | 80 | |
| jarkman | 0:b55ca3bb8017 | 81 | int SerialBuffered::readable() |
| jarkman | 0:b55ca3bb8017 | 82 | { |
| jarkman | 0:b55ca3bb8017 | 83 | return m_contentStart != m_contentEnd ; |
| jarkman | 0:b55ca3bb8017 | 84 | } |
| jarkman | 0:b55ca3bb8017 | 85 | |
| jarkman | 0:b55ca3bb8017 | 86 | void SerialBuffered::handleInterrupt() |
| jarkman | 0:b55ca3bb8017 | 87 | { |
| jarkman | 0:b55ca3bb8017 | 88 | |
| jarkman | 0:b55ca3bb8017 | 89 | while( Serial::readable()) |
| jarkman | 0:b55ca3bb8017 | 90 | { |
| jarkman | 0:b55ca3bb8017 | 91 | if( m_contentStart == (m_contentEnd +1) % m_buffSize) |
| jarkman | 0:b55ca3bb8017 | 92 | { |
| jarkman | 0:b55ca3bb8017 | 93 | loggerSerial.printf("SerialBuffered - buffer overrun, data lost!\r\n" ); |
| jarkman | 0:b55ca3bb8017 | 94 | Serial::getc(); |
| jarkman | 0:b55ca3bb8017 | 95 | |
| jarkman | 0:b55ca3bb8017 | 96 | } |
| jarkman | 0:b55ca3bb8017 | 97 | else |
| jarkman | 0:b55ca3bb8017 | 98 | { |
| jarkman | 0:b55ca3bb8017 | 99 | |
| jarkman | 0:b55ca3bb8017 | 100 | m_buff[ m_contentEnd ++ ] = Serial::getc(); |
| jarkman | 0:b55ca3bb8017 | 101 | m_contentEnd = m_contentEnd % m_buffSize; |
| jarkman | 0:b55ca3bb8017 | 102 | |
| jarkman | 0:b55ca3bb8017 | 103 | |
| jarkman | 0:b55ca3bb8017 | 104 | |
| jarkman | 0:b55ca3bb8017 | 105 | } |
| jarkman | 0:b55ca3bb8017 | 106 | } |
| jarkman | 0:b55ca3bb8017 | 107 | } |
| jarkman | 0:b55ca3bb8017 | 108 |