gcc4mbed/external/mbed/SerialHalfDuplex.h

   1 /* mbed Microcontroller Library - SerialHalfDuplex
   2  * Copyright (c) 2010-2011 ARM Limited. All rights reserved.
   3  */
   4
   5 #ifndef MBED_SERIALHALFDUPLEX_H
   6 #define MBED_SERIALHALFDUPLEX_H
   7
   8 #include "device.h"
   9
  10 #if DEVICE_SERIAL
  11
  12 #include "Serial.h"
  13 #include "PinNames.h"
  14 #include "PeripheralNames.h"
  15
  16 namespace mbed {
  17
  18 /* Class: SerialHalfDuplex
  19  * A serial port (UART) for communication with other devices using
  20  * Half-Duplex, allowing transmit and receive on a single
  21  * shared transmit and receive line. Only one end should be transmitting
  22  * at a time.
  23  *
  24  * Both the tx and rx pin should be defined, and wired together.
  25  * This is in addition to them being wired to the other serial
  26  * device to allow both read and write functions to operate.
  27  *
  28  *  Example:
  29  *  > // Send a byte to a second HalfDuplex device, and read the response
  30  *  >
  31  *  > #include "mbed.h"
  32  *  >
  33  *  > // p9 and p10 should be wired together to form "a"
  34  *  > // p28 and p27 should be wired together to form "b"
  35  *  > // p9/p10 should be wired to p28/p27 as the Half Duplex connection
  36  *  >
  37  *  > SerialHalfDuplex a(p9, p10);
  38  *  > SerialHalfDuplex b(p28, p27);
  39  *  >
  40  *  > void b_rx() { // second device response
  41  *  >     b.putc(b.getc() + 4);
  42  *  > }
  43  *  >
  44  *  > int main() {
  45  *  >     b.attach(&b_rx);
  46  *  >     for(int c = 'A'; c < 'Z'; c++) {
  47  *  >         a.putc(c);
  48  *  >         printf("sent [%c]\n", c);
  49  *  >         wait(0.5);   // b should respond
  50  *  >         if(a.readable()) {
  51  *  >             printf("received [%c]\n", a.getc());
  52  *  >         }
  53  *  >     }
  54  *  > }
  55  *
  56  * For Simplex and Full-Duplex Serial communication, see <Serial>
  57  */
  58 class SerialHalfDuplex : public Serial {
  59
  60 public:
  61     /* Constructor: SerialHalfDuplex
  62      * Create a half-duplex serial port, connected to the specified transmit
  63      * and receive pins.
  64      *
  65      * These pins should be wired together, as well as to the target device
  66      *
  67      * Variables:
  68      *  tx - Transmit pin
  69      *  rx - Receive pin
  70      */
  71     SerialHalfDuplex(PinName tx, PinName rx, const char *name = NULL);
  72
  73 #if 0       // Inherited from Serial class, for documentation
  74     /* Function: baud
  75      *  Set the baud rate of the serial port
  76      *
  77      * Variables:
  78      *  baudrate - The baudrate of the serial port (default = 9600).
  79      */
  80     void baud(int baudrate);
  81
  82     enum Parity {
  83         None = 0
  84         , Odd
  85         , Even
  86         , Forced1
  87         , Forced0
  88     };
  89
  90     /* Function: format
  91      *  Set the transmission format used by the Serial port
  92      *
  93      * Variables:
  94      *  bits - The number of bits in a word (5-8; default = 8)
  95      *  parity - The parity used (Serial::None, Serial::Odd,
  96 Serial::Even, Serial::Forced1, Serial::Forced0; default = Serial::None)
  97      *  stop - The number of stop bits (1 or 2; default = 1)
  98      */
  99     void format(int bits = 8, Parity parity = Serial::None, int stop_bits
 100 = 1);
 101
 102     /* Function: putc
 103      *  Write a character
 104      *
 105      * Variables:
 106      *  c - The character to write to the serial port
 107      */
 108     int putc(int c);
 109
 110     /* Function: getc
 111      *  Read a character
 112      *
 113      * Read a character from the serial port. This call will block
 114      * until a character is available. For testing if a character is
 115      * available for reading, see <readable>.
 116      *
 117      * Variables:
 118      *  returns - The character read from the serial port
 119      */
 120     int getc();
 121
 122     /* Function: printf
 123      *  Write a formated string
 124      *
 125      * Variables:
 126      *  format - A printf-style format string, followed by the
 127      *      variables to use in formating the string.
 128      */
 129     int printf(const char* format, ...);
 130
 131     /* Function: scanf
 132      *  Read a formated string
 133      *
 134      * Variables:
 135      *  format - A scanf-style format string,
 136      *      followed by the pointers to variables to store the results.
 137      */
 138     int scanf(const char* format, ...);
 139
 140     /* Function: readable
 141      *  Determine if there is a character available to read
 142      *
 143      * Variables:
 144      *  returns - 1 if there is a character available to read, else 0
 145      */
 146     int readable();
 147
 148     /* Function: writeable
 149      *  Determine if there is space available to write a character
 150      *
 151      * Variables:
 152      *  returns - 1 if there is space to write a character, else 0
 153      */
 154     int writeable();
 155
 156     /* Function: attach
 157      *  Attach a function to call whenever a serial interrupt is generated
 158      *
 159      * Variables:
 160      *  fptr - A pointer to a void function, or 0 to set as none
 161      */
 162     void attach(void (*fptr)(void));
 163
 164     /* Function: attach
 165      *  Attach a member function to call whenever a serial interrupt is generated
 166      *
 167      * Variables:
 168      *  tptr - pointer to the object to call the member function on
 169      *  mptr - pointer to the member function to be called
 170      */
 171     template<typename T>
 172     void attach(T* tptr, void (T::*mptr)(void));
 173
 174 #endif
 175
 176 protected:
 177     PinName     _txpin;
 178
 179     virtual int _putc(int c);
 180     virtual int _getc(void);
 181
 182 }; // End class SerialHalfDuplex
 183
 184 } // End namespace
 185
 186 #endif
 187
 188 #endif