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/* mbed Microcontroller Library - SerialHalfDuplex
* Copyright (c) 2010-2011 ARM Limited. All rights reserved.
*/
#ifndef MBED_SERIALHALFDUPLEX_H
#define MBED_SERIALHALFDUPLEX_H
#include "platform.h"
#if DEVICE_SERIAL
#include "Serial.h"
#include "gpio_api.h"
namespace mbed {
/** A serial port (UART) for communication with other devices using
* Half-Duplex, allowing transmit and receive on a single
* shared transmit and receive line. Only one end should be transmitting
* at a time.
*
* Both the tx and rx pin should be defined, and wired together.
* This is in addition to them being wired to the other serial
* device to allow both read and write functions to operate.
*
* For Simplex and Full-Duplex Serial communication, see Serial()
*
* Example:
* @code
* // Send a byte to a second HalfDuplex device, and read the response
*
* #include "mbed.h"
*
* // p9 and p10 should be wired together to form "a"
* // p28 and p27 should be wired together to form "b"
* // p9/p10 should be wired to p28/p27 as the Half Duplex connection
*
* SerialHalfDuplex a(p9, p10);
* SerialHalfDuplex b(p28, p27);
*
* void b_rx() { // second device response
* b.putc(b.getc() + 4);
* }
*
* int main() {
* b.attach(&b_rx);
* for (int c = 'A'; c < 'Z'; c++) {
* a.putc(c);
* printf("sent [%c]\n", c);
* wait(0.5); // b should respond
* if (a.readable()) {
* printf("received [%c]\n", a.getc());
* }
* }
* }
* @endcode
*/
class SerialHalfDuplex : public Serial {
public:
/** Create a half-duplex serial port, connected to the specified transmit
* and receive pins.
*
* These pins should be wired together, as well as to the target device
*
* @param tx Transmit pin
* @param rx Receive pin
*/
SerialHalfDuplex(PinName tx, PinName rx);
protected:
gpio_object gpio;
virtual int _putc(int c);
virtual int _getc(void);
}; // End class SerialHalfDuplex
} // End namespace
#endif
#endif
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