Revision 0:8edaa7abe724, committed 2014-04-26

Comitter:

Sissors

Date:

Sat Apr 26 14:46:03 2014 +0000

Child:

1:f8b4b764ace7

Commit message:

TX basic finished

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SoftSerial.cpp	Sat Apr 26 14:46:03 2014 +0000
@@ -0,0 +1,29 @@
+#include "SoftSerial.h"
+
+SoftSerial::SoftSerial(PinName TX, PinName RX) {
+    tx_en = rx_en = false;
+    if (TX != NC) {
+        tx = new DigitalOut(TX);
+        tx_en = true;
+        tx->write(1);
+        tx_bit = -1;
+    }
+    if (RX != NC) {
+        rx = new InterruptIn(RX);
+        rx_en = true;
+        rx->fall(this, &SoftSerial::rx_gpio_irq_handler);
+    }
+    
+    baud(9600);
+    format();
+}
+
+void SoftSerial::baud(int baudrate) {
+    bit_period = 1000000 / baudrate;
+}
+
+void SoftSerial::format(int bits, Parity parity, int stop_bits) {
+    _bits = bits;
+    _parity = parity;
+    _stop_bits = stop_bits;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SoftSerial.h	Sat Apr 26 14:46:03 2014 +0000
@@ -0,0 +1,111 @@
+#ifndef SOFTSERIAL_H
+#define SOFTSERIAL_H
+
+#include "mbed.h"
+
+/** A software serial implementation
+ *
+ */
+class SoftSerial: public Stream {
+
+public:
+    /**
+    * Constructor
+    *
+    * @param TX Name of the TX pin, NC for not connected
+    * @param RX Name of the RX pin, NC for not connected, must be capable of being InterruptIn
+    */
+    SoftSerial(PinName TX, PinName RX);
+    
+    /** Set the baud rate of the serial port
+     *
+     *  @param baudrate The baudrate of the serial port (default = 9600).
+     */
+    void baud(int baudrate);
+
+    enum Parity {
+        None = 0,
+        Odd,
+        Even,
+        Forced1,
+        Forced0
+    };
+
+    enum IrqType {
+        RxIrq = 0,
+        TxIrq
+    };
+
+    /** Set the transmission format used by the serial port
+     *
+     *  @param bits The number of bits in a word (default = 8)
+     *  @param parity The parity used (SerialBase::None, SerialBase::Odd, SerialBase::Even, SerialBase::Forced1, SerialBase::Forced0; default = SerialBase::None)
+     *  @param stop The number of stop bits (default = 1)
+     */
+    void format(int bits=8, Parity parity=SoftSerial::None, int stop_bits=1);
+
+    /** Determine if there is a character available to read
+     *
+     *  @returns
+     *    1 if there is a character available to read,
+     *    0 otherwise
+     */
+    int readable();
+
+    /** Determine if there is space available to write a character
+     *
+     *  @returns
+     *    1 if there is space to write a character,
+     *    0 otherwise
+     */
+    int writeable();
+
+    /** Attach a function to call whenever a serial interrupt is generated
+     *
+     *  @param fptr A pointer to a void function, or 0 to set as none
+     *  @param type Which serial interrupt to attach the member function to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)
+     */
+    void attach(void (*fptr)(void), IrqType type=RxIrq);
+
+    /** Attach a member function to call whenever a serial interrupt is generated
+     *
+     *  @param tptr pointer to the object to call the member function on
+     *  @param mptr pointer to the member function to be called
+     *  @param type Which serial interrupt to attach the member function to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)
+     */
+    template<typename T>
+    void attach(T* tptr, void (T::*mptr)(void), IrqType type=RxIrq);
+
+    /** Generate a break condition on the serial line
+     */
+    void send_break();
+
+protected:
+    DigitalOut *tx;
+    InterruptIn *rx;
+    
+    bool tx_en, rx_en;
+    int bit_period;
+    int _bits, _stop_bits;
+    Parity _parity;
+    
+    void rx_gpio_irq_handler(void);
+    void rx_fall_handler(void);
+    void rx_handler(bool rise);
+    
+    //tx
+    void tx_handler(void);
+    inline int get_bit(int bit);
+    Timeout timeout;
+    int _char;
+    volatile int tx_bit;
+    
+    
+    
+    virtual int _getc();
+    virtual int _putc(int c);
+};
+
+
+#endif
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SoftSerial_rx.cpp	Sat Apr 26 14:46:03 2014 +0000
@@ -0,0 +1,10 @@
+#include "SoftSerial.h"
+
+int SoftSerial::_getc( void ) {
+    return 0;
+    }
+
+void SoftSerial::rx_gpio_irq_handler(void) {
+    
+};    
+ 
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SoftSerial_tx.cpp	Sat Apr 26 14:46:03 2014 +0000
@@ -0,0 +1,77 @@
+#include "SoftSerial.h"
+
+int SoftSerial::_putc(int c) {
+    while(!writeable());
+    tx_bit = 0;
+    _char = c;
+    tx_handler();
+    return 0;
+    }
+
+int SoftSerial::writeable(void) {
+    if (!tx_en)
+        return false;
+    if (tx_bit == -1)
+        return true;
+    return false;
+}
+
+void SoftSerial::tx_handler(void) {
+    if (get_bit(tx_bit) == -1) {
+        tx_bit = -1;
+        return;
+    }
+    
+    //Flip output
+    int cur_out = tx->read();
+    tx->write(!cur_out);
+         
+    //Calculate when to do it again
+    int count = bit_period;
+    tx_bit++;
+    while(get_bit(tx_bit) == !cur_out) {
+        count+=bit_period;
+        tx_bit++;
+    }
+    
+    timeout.attach_us(this, &SoftSerial::tx_handler, count);
+}
+
+int SoftSerial::get_bit(int bit) {
+    //Start bit is never asked
+    
+    //Data bits
+    if (bit <= _bits )
+        return ((_char >> (bit - 1)) & 0x01);
+    
+    //Parity
+    bool retval;
+    if (bit == _bits + 1) {
+        switch (_parity) {
+            case Forced1:
+                return 1;
+            case Forced0:
+                return 0;
+            case Even:
+                retval = false;
+                for (int i = 0; i<_bits; i++) {
+                    if (((_char >> i) & 0x01) == 1)
+                        retval = !retval;
+                }
+                return retval;
+            case Odd:
+                retval = true;
+                for (int i = 0; i<_bits; i++) {
+                    if (((_char >> i) & 0x01) == 1)
+                        retval = !retval;
+                }
+                return retval;
+        }
+    }
+    
+    //Stop bits:
+    if (bit < 1 + _bits + (bool)_parity + _stop_bits) 
+        return 1;
+    
+    return -1;   
+}
\ No newline at end of file