BufferedSerial.h

00001 /**
00002  * \copyright Copyright 2017, Helium Systems, Inc.
00003  * All Rights Reserved. See LICENSE.txt for license information
00004  */
00005 
00006 #include "mbed.h"
00007 #include "RingBuffer.h"
00008 
00009 #ifndef BUFFEREDSERIAL_H
00010 #define BUFFEREDSERIAL_H
00011 
00012 /**
00013  * \class BufferedSerial
00014  *
00015  * \brief Implements a buffered serial port
00016  *
00017  * This is a simple buffered serial port to work around `readable`
00018  * issues on a number of mbed implementations. Receiving on the serial
00019  * port is buffered through an interrupt handler.
00020  *
00021  * Note that writing is not buffered at this time since writing to the
00022  * serial port at speed had not been an issue so far.
00023  */
00024 class BufferedSerial : public RawSerial
00025 {
00026   public:
00027     /** Crete a buffered serial port.
00028      *
00029      * @param tx Serial port tx pin to use
00030      * @param rx Serial port rx pin to use
00031      * @param baud The baud rate to use. Defaults to the default for the current
00032      * board
00033      */
00034     BufferedSerial(PinName tx,
00035                    PinName rx,
00036                    int     baud = MBED_CONF_PLATFORM_DEFAULT_SERIAL_BAUD_RATE);
00037 
00038     /** Destructor */
00039     ~BufferedSerial();
00040 
00041 
00042     /** Sets the baud rate for the serial port
00043      *
00044      * @param baud The baud rate to set on the serial port
00045      */
00046     void baud(int baud);
00047 
00048     /** Get a byte from the serial port buffer.
00049      *
00050      * @return a buffered byte or -1 if no bytes are available
00051      */
00052     int getc();
00053 
00054     /** Write a byte to the serial port
00055      *
00056      * @param ch The byte to write
00057      * @return the byte that was written
00058      */
00059     int putc(int ch);
00060 
00061     /** Check if there are bytes to read.
00062      *
00063      * @return 1 if bytes are available, 0 otherwise
00064      */
00065     int readable();
00066 
00067 
00068   private:
00069     RingBuffer<uint8_t, 16> _rx_buffer;
00070     void _rx_interrupt();
00071 
00072 };
00073 
00074 
00075 #endif