SoftSerial.h

00001 /*
00002     Original Library by Erik- & SonyPony
00003     https://os.mbed.com/users/Sissors/code/SoftSerial/
00004 
00005     Modified by K.Arai / JH1PJL     May 12th, 2020
00006 
00007     modified functions
00008         tx_handler()
00009         prepare_tx()
00010         prime()
00011         rx_gpio_irq_handler() and others
00012  */
00013 
00014 #ifndef SOFTSERIAL_H
00015 #define SOFTSERIAL_H
00016 
00017 #include "mbed.h"
00018 #include "SoftSerial_Ticker.h"
00019 
00020 #define DEBUG_TIMING    0   // 0=no debug, 1=tx, 2=rx
00021 
00022 #if (MBED_MAJOR_VERSION == 2)
00023 #   define  YIELD   {;}
00024 #elif (MBED_MAJOR_VERSION == 5)
00025 #   define  YIELD   {ThisThread::yield();}
00026 #endif
00027 
00028 /** A software serial implementation
00029  *
00030  */
00031 class SoftSerial: public Stream
00032 {
00033 
00034 public:
00035     /**
00036     * Constructor
00037     *
00038     * @param TX Name of the TX pin, NC for not connected
00039     * @param RX Name of the RX pin, NC for not connected,
00040     *        must be capable of being InterruptIn
00041     * @param name Name of the connection
00042     */
00043     SoftSerial(PinName TX, PinName RX, const char* name = NULL);
00044     virtual ~SoftSerial();
00045 
00046     /** Set the baud rate of the serial port
00047      *
00048      *  @param baudrate The baudrate of the serial port (default = 9600).
00049      */
00050     void baud(int baudrate);
00051 
00052     enum Parity {
00053         None = 0,
00054         Odd,
00055         Even,
00056         Forced1,
00057         Forced0
00058     };
00059 
00060     enum IrqType {
00061         RxIrq = 0,
00062         TxIrq
00063     };
00064 
00065     /** Set the transmission format used by the serial port
00066      *
00067      *  @param bits The number of bits in a word (default = 8)
00068      *  @param parity The parity used
00069      *   (SoftSerial::None, SoftSerial::Odd, SoftSerial::Even,
00070      *   SoftSerial::Forced1, SoftSerial::Forced0; default = SoftSerial::None)
00071      *  @param stop The number of stop bits (default = 1)
00072      */
00073     void format(int bits=8, Parity parity=SoftSerial::None, int stop_bits=1);
00074 
00075     /** Determine if there is a character available to read
00076      *
00077      *  @returns
00078      *    1 if there is a character available to read,
00079      *    0 otherwise
00080      */
00081     int readable();
00082 
00083     /** Determine if there is space available to write a character
00084      *
00085      *  @returns
00086      *    1 if there is space to write a character,
00087      *    0 otherwise
00088      */
00089     int writeable();
00090 
00091     /** Attach a function to call whenever a serial interrupt is generated
00092      *
00093      *  @param fptr A pointer to a void function, or 0 to set as none
00094      *  @param type Which serial interrupt to attach the member function
00095      *       to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)
00096      */
00097     void attach(void (*fptr)(void), IrqType type=RxIrq)
00098     {
00099         fpointer[type] = Callback<void()>(fptr);
00100     }
00101 
00102     /** Attach a member function to call
00103      *      whenever a serial interrupt is generated
00104      *
00105      *  @param tptr pointer to the object to call the member function on
00106      *  @param mptr pointer to the member function to be called
00107      *  @param type Which serial interrupt to attach the member function
00108      *       to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)
00109      */
00110     template<typename T>
00111     void attach(T* tptr, void (T::*mptr)(void), IrqType type=RxIrq)
00112     {
00113         fpointer[type] = Callback<void()>(tptr, mptr);
00114     }
00115 
00116     /** Generate a break condition on the serial line
00117      */
00118     void send_break();
00119 
00120 protected:
00121     DigitalOut *tx;
00122     InterruptIn *rx;
00123 
00124     bool tx_en, rx_en;
00125     int bit_period;
00126     int _bits, _stop_bits, _total_bits;
00127     Parity _parity;
00128 
00129     Callback<void()>  fpointer[2];
00130 
00131     //rx
00132     void rx_gpio_irq_handler(void);
00133     void rx_handler(void);
00134     int read_buffer, rx_bit;
00135     volatile int out_buffer;
00136     volatile bool out_valid;
00137     bool rx_error;
00138     FlexTicker rxticker;
00139 
00140     bool rx_1st;
00141     uint32_t rx_st_time;
00142 
00143     //tx
00144     void tx_handler(void);
00145     void prepare_tx(int c);
00146     FlexTicker txticker;
00147     int _char;
00148     volatile int tx_bit;
00149 
00150     virtual int _getc();
00151     virtual int _putc(int c);
00152 };
00153 
00154 #endif