Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

features/unsupported/tests/libs/SerialHalfDuplex/SerialHalfDuplex.h@1:3deb71413561, 2017-07-20 (annotated)

Committer:
xuaner
Date:
Thu Jul 20 14:26:57 2017 +0000
Revision:
1:3deb71413561
Parent:
0:f269e3021894 
mbed_os

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library - SerialHalfDuplex
elessair 0:f269e3021894 2 * Copyright (c) 2010-2011 ARM Limited. All rights reserved.
elessair 0:f269e3021894 3 */
elessair 0:f269e3021894 4 #ifndef MBED_SERIALHALFDUPLEX_H
elessair 0:f269e3021894 5 #define MBED_SERIALHALFDUPLEX_H
elessair 0:f269e3021894 6
elessair 0:f269e3021894 7 #include "platform.h"
elessair 0:f269e3021894 8
elessair 0:f269e3021894 9 #if DEVICE_SERIAL
elessair 0:f269e3021894 10
elessair 0:f269e3021894 11 #include "Serial.h"
elessair 0:f269e3021894 12 #include "gpio_api.h"
elessair 0:f269e3021894 13
elessair 0:f269e3021894 14 namespace mbed {
elessair 0:f269e3021894 15
elessair 0:f269e3021894 16 /** A serial port (UART) for communication with other devices using
elessair 0:f269e3021894 17 * Half-Duplex, allowing transmit and receive on a single
elessair 0:f269e3021894 18 * shared transmit and receive line. Only one end should be transmitting
elessair 0:f269e3021894 19 * at a time.
elessair 0:f269e3021894 20 *
elessair 0:f269e3021894 21 * Both the tx and rx pin should be defined, and wired together.
elessair 0:f269e3021894 22 * This is in addition to them being wired to the other serial
elessair 0:f269e3021894 23 * device to allow both read and write functions to operate.
elessair 0:f269e3021894 24 *
elessair 0:f269e3021894 25 * For Simplex and Full-Duplex Serial communication, see Serial()
elessair 0:f269e3021894 26 *
elessair 0:f269e3021894 27 * Example:
elessair 0:f269e3021894 28 * @code
elessair 0:f269e3021894 29 * // Send a byte to a second HalfDuplex device, and read the response
elessair 0:f269e3021894 30 *
elessair 0:f269e3021894 31 * #include "mbed.h"
elessair 0:f269e3021894 32 *
elessair 0:f269e3021894 33 * // p9 and p10 should be wired together to form "a"
elessair 0:f269e3021894 34 * // p28 and p27 should be wired together to form "b"
elessair 0:f269e3021894 35 * // p9/p10 should be wired to p28/p27 as the Half Duplex connection
elessair 0:f269e3021894 36 *
elessair 0:f269e3021894 37 * SerialHalfDuplex a(p9, p10);
elessair 0:f269e3021894 38 * SerialHalfDuplex b(p28, p27);
elessair 0:f269e3021894 39 *
elessair 0:f269e3021894 40 * void b_rx() { // second device response
elessair 0:f269e3021894 41 * b.putc(b.getc() + 4);
elessair 0:f269e3021894 42 * }
elessair 0:f269e3021894 43 *
elessair 0:f269e3021894 44 * int main() {
elessair 0:f269e3021894 45 * b.attach(&b_rx);
elessair 0:f269e3021894 46 * for (int c = 'A'; c < 'Z'; c++) {
elessair 0:f269e3021894 47 * a.putc(c);
elessair 0:f269e3021894 48 * printf("sent [%c]\n", c);
elessair 0:f269e3021894 49 * wait(0.5); // b should respond
elessair 0:f269e3021894 50 * if (a.readable()) {
elessair 0:f269e3021894 51 * printf("received [%c]\n", a.getc());
elessair 0:f269e3021894 52 * }
elessair 0:f269e3021894 53 * }
elessair 0:f269e3021894 54 * }
elessair 0:f269e3021894 55 * @endcode
elessair 0:f269e3021894 56 */
elessair 0:f269e3021894 57 class SerialHalfDuplex : public Serial {
elessair 0:f269e3021894 58
elessair 0:f269e3021894 59 public:
elessair 0:f269e3021894 60 /** Create a half-duplex serial port, connected to the specified transmit
elessair 0:f269e3021894 61 * and receive pins.
elessair 0:f269e3021894 62 *
elessair 0:f269e3021894 63 * These pins should be wired together, as well as to the target device
elessair 0:f269e3021894 64 *
elessair 0:f269e3021894 65 * @param tx Transmit pin
elessair 0:f269e3021894 66 * @param rx Receive pin
elessair 0:f269e3021894 67 */
elessair 0:f269e3021894 68 SerialHalfDuplex(PinName tx, PinName rx);
elessair 0:f269e3021894 69
elessair 0:f269e3021894 70 protected:
elessair 0:f269e3021894 71 gpio_object gpio;
elessair 0:f269e3021894 72
elessair 0:f269e3021894 73 virtual int _putc(int c);
elessair 0:f269e3021894 74 virtual int _getc(void);
elessair 0:f269e3021894 75
elessair 0:f269e3021894 76 }; // End class SerialHalfDuplex
elessair 0:f269e3021894 77
elessair 0:f269e3021894 78 } // End namespace
elessair 0:f269e3021894 79
elessair 0:f269e3021894 80 #endif
elessair 0:f269e3021894 81
elessair 0:f269e3021894 82 #endif