SoftwareSerial.h

00001 // modified from mbed library, original copyright:
00002 
00003 /* mbed Microcontroller Library - Serial
00004  * Copyright (c) 2007-2011 ARM Limited. All rights reserved.
00005  */ 
00006 
00007 
00008 #ifndef SOFTWARE_SERIAL_H
00009 #define SOFTWARE_SERIAL_H
00010 
00011 #ifndef SOFTWARE_SERIAL_RX_BUFFER_SIZE
00012 #define SOFTWARE_SERIAL_RX_BUFFER_SIZE 256
00013 #endif
00014 
00015 
00016 #include "mbed.h"
00017 
00018 
00019 namespace SoftwareSerial {
00020 
00021 /* Class: SoftwareSerial
00022  *  A software implemented serial port (UART) for communication with other serial devices
00023  *
00024  * Can be used for Full Duplex communication, or Simplex by specifying 
00025  * one pin as NC (Not Connected)
00026  *
00027  * Example:
00028  * > // Print "Hello World" to the PC
00029  * >
00030  * > #include "mbed.h"
00031  * > #include "SoftwareSerial.h"
00032  * >
00033  * > SoftwareSerial ser(P19, P20);
00034  * >
00035  * > int main() {
00036  * >     ser.printf("Hello World\n");
00037  * > }
00038  */
00039 class SoftwareSerial : public Stream {
00040 
00041 public:
00042 
00043     /* Constructor: SoftwareSerial
00044      *  Create a SoftwareSerial port, connected to the specified transmit and receive pins
00045      *
00046      * Variables:
00047      *  tx - Transmit pin 
00048      *  rx - Receive pin
00049      *
00050      *  Note: Either tx or rx may be specified as NC if unused
00051      */
00052     SoftwareSerial(PinName tx, PinName rx, const char *name = NULL);
00053 
00054     /* Function: baud
00055      *  Set the baud rate of the serial port
00056      *  
00057      * Variables:
00058      *  baudrate - The baudrate of the serial port (default = 9600).
00059      */
00060     void baud(int baudrate);
00061 
00062     /*enum Parity {
00063         None = 0
00064         , Odd
00065         , Even
00066         , Forced1    
00067         , Forced0
00068     };*/
00069 
00070     enum IrqType {
00071         RxIrq = 0
00072         , TxIrq
00073     };
00074 
00075     /* Function: format
00076      *  Set the transmission format used by the Serial port
00077      *
00078      * Variables:
00079      *  bits - The number of bits in a word (5-8; default = 8)
00080      *  parity - The parity used (SoftwareSerial::None, SoftwareSerial::Odd, SoftwareSerial::Even, SoftwareSerial::Forced1, SoftwareSerial::Forced0; default = SoftwareSerial::None)
00081      *  stop - The number of stop bits (1 or 2; default = 1)
00082      */
00083     /*void format(int bits = 8, Parity parity = Serial::None, int stop_bits = 1); */
00084 
00085 #if 0 // Inhereted from Stream, for documentation only
00086 
00087     /* Function: putc
00088      *  Write a character
00089      *
00090      * Variables:
00091      *  c - The character to write to the serial port
00092      */
00093     int putc(int c);
00094 
00095 
00096     /* Function: getc
00097      *  Read a character
00098      *
00099      * Reads a character from the serial port. This will block until 
00100      * a character is available. To see if a character is available, 
00101      * see <readable>
00102      *
00103      * Variables:
00104      *  returns - The character read from the serial port
00105      */
00106     int getc();
00107 
00108     /* Function: printf
00109      *  Write a formated string
00110      *
00111      * Variables:
00112      *  format - A printf-style format string, followed by the 
00113      *      variables to use in formating the string.
00114      */
00115     int printf(const char* format, ...);
00116 
00117     /* Function: scanf
00118      *  Read a formated string 
00119      *
00120      * Variables:
00121      *  format - A scanf-style format string,
00122      *      followed by the pointers to variables to store the results. 
00123      */
00124     int scanf(const char* format, ...);
00125  
00126 #endif
00127 
00128 
00129 #if 1
00130     /** putc
00131      * @param int c The byte to write.
00132      */
00133     int  putc(int c);
00134     
00135     /** puts
00136      * @param char * The string to print.
00137      */
00138     //void puts(char *s);
00139     
00140     /** getc
00141      * @return int c The byte read or -1 if no bytes to read.
00142      */
00143     int  getc(void); 
00144     
00145     /** gets
00146      * Get a string. Note, this method blocks until size bytes are read.
00147      * @param char *s where to place the incoming bytes.
00148      * @param int size How many bytes to read.
00149      * @return char * The value of *s passed in.
00150      */
00151     //char *gets(char *s, int size);   
00152     
00153     /** peek
00154      * like getc() but does NOT remove the byte from the buffer.
00155      * @see getc*(
00156      */
00157     //int  peek(void);
00158         
00159 #endif
00160  
00161     /* Function: readable
00162      *  Determine if there is a character available to read
00163      *
00164      * Variables:
00165      *  returns - 1 if there is a character available to read, else 0
00166      */
00167     int readable();
00168 
00169     /* Function: writeable
00170      *  Determine if there is space available to write a character
00171      * 
00172      * Variables:
00173      *  returns - 1 if there is space to write a character, else 0
00174      */
00175     int writeable();
00176 
00177     /* Function: attach
00178      *  Attach a function to call whenever a serial interrupt is generated
00179      *
00180      * Variables:
00181      *  fptr - A pointer to a void function, or 0 to set as none
00182      *  type - Which serial interrupt to attach the member function to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)
00183      */
00184     //void attach(void (*fptr)(void), IrqType type = RxIrq);
00185 
00186     /* Function: attach
00187      *  Attach a member function to call whenever a serial interrupt is generated
00188      *     
00189      * Variables:
00190      *  tptr - pointer to the object to call the member function on
00191      *  mptr - pointer to the member function to be called
00192      *  type - Which serial interrupt to attach the member function to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)
00193      */
00194     template<typename T>
00195     void attach(T* tptr, void (T::*mptr)(void), IrqType type = RxIrq) {
00196         if((mptr != NULL) && (tptr != NULL)) {
00197             _irq[type].attach(tptr, mptr);
00198             setup_interrupt(type);
00199         }
00200     }
00201 
00202 #ifdef MBED_RPC
00203     //virtual const struct rpc_method *get_rpc_methods();
00204     static struct rpc_class *get_rpc_class();
00205 #endif
00206 
00207 protected:
00208 
00209     //void setup_interrupt(IrqType type);
00210     //void remove_interrupt(IrqType type);
00211 
00212     //UARTName _uart;
00213     //FunctionPointer _irq[2];
00214     //int _uidx;
00215     
00216     virtual int _putc(int c) { return putc(c); }
00217     virtual int _getc()      { return getc(); }
00218     
00219 
00220 
00221     int get_rx_pin_status();
00222     void set_tx_pin_high();
00223     void set_tx_pin_low();
00224     void idle();
00225     void timer_set( int baud );
00226     void set_timer_interrupt( void (*timer_isr)(void) );
00227   
00228     
00229     
00230     void timer_isr( void );
00231     void init_uart( void );
00232     //char _getchar( void );
00233     //void _putchar( char ch );
00234     void flush_input_buffer( void );
00235     char kbhit( void );
00236     void turn_rx_on( void );
00237     void turn_rx_off( void );
00238     
00239 
00240 private:
00241     DigitalOut *tx;
00242     DigitalIn *rx;
00243     
00244     Ticker ticker;
00245     
00246     int baud_rate;
00247 
00248     unsigned char inbuf[SOFTWARE_SERIAL_RX_BUFFER_SIZE];
00249     unsigned char qin;
00250     unsigned char qout;
00251     char flag_rx_waiting_for_stop_bit;
00252     bool flag_rx_off;
00253     char rx_mask;
00254     bool flag_rx_ready;
00255     bool flag_tx_ready;
00256     char timer_rx_ctr;
00257     char timer_tx_ctr;
00258     char bits_left_in_rx;
00259     char bits_left_in_tx;
00260     char rx_num_of_bits;
00261     char tx_num_of_bits;
00262     char internal_rx_buffer;
00263     char internal_tx_buffer;
00264     char user_tx_buffer;
00265 
00266 };
00267 
00268 } // namespace
00269 
00270 using namespace SoftwareSerial;
00271 
00272 #endif