Diff: rs485.cpp

Revision:

1:2c9d412ad471

Parent:

0:7f26f0680202

--- a/rs485.cpp	Fri Dec 31 14:01:14 2010 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,187 +0,0 @@
-#include "mbed.h"
-#include "data.h"
-
-#define TXMODE  true        /* level of eg. MAX485 input to switch to transmit mode */
-#define RXMODE  (!TXMODE)
-
-class rs485: public Serial, DigitalOut { //since communication is half duplex we use only one buffer for both reading and writing
-    char *buffer;
-    int index, length; //index is the buffer pointer, length is the length of the buffer
-    //bool receiving;
-    bool _done;
-    virtual void rx() { //ISR that stashes bytes until the buffer is full and then disables itself
-        //if (!receiving)return;
-        if (index<length)
-            buffer[index++] = getc();
-        else {
-            //receiving = false;
-            attach(0);
-            _done = true;
-        }
-    }
-    virtual void tx() { //ISR that sends out the entire buffer and then switches to receive mode
-        if (index<length)
-            putc(buffer[index++]);
-        else {
-            DigitalOut::write(RXMODE);
-            attach(this,&rs485::rx, RxIrq);
-            _done = true;
-        }
-    }
-public:
-    enum mode_t { rec, trans};
-    rs485(PinName out, PinName in, PinName dir): Serial(out, in), DigitalOut(dir) {
-        //attach(this, rx, RxIrq);
-        attach(this, &rs485::tx, TxIrq);
-        DigitalOut::write(RXMODE);
-        buffer = 0;
-        length = 0;
-        //receiving = false;
-    }
-    //void init(int br) {}
-    void send(char *buf, int len) {
-        DigitalOut::write(TXMODE);
-        buffer = buf;
-        length = len;
-        putc(*buffer);
-        index = 1;
-    }
-    void receive(char *buf, int len) {
-        buffer = buf;
-        length = len;
-        //receiving = true;
-        attach(this,&rs485::rx, RxIrq);
-    }
-    bool done() {
-        bool tmp = _done;
-        _done=false;
-        return tmp;
-    }
-    void setmode(enum mode_t m) {
-        if (m==rec)
-            DigitalOut::write(RXMODE);
-        else
-            DigitalOut::write(TXMODE);
-    }
-};
-
-
-//class specialized for use with the fischertechnik TXC
-class TXC_rs485: public rs485 {
-    message *msg; //pointer to a TXC message buffer
-    char *wp; //pointer where the receiver will write the data
-    int rpos; //index where the transmitter will read the data
-    virtual void rx(); //ISR
-    virtual void tx(); //ISR 
-    char state;  //receiver state
-    int rs485_timeout; // a timeout period, intended to reset the receiver when interrupts stop before the end of a message
-    int tx_message; //the destination of a received message, i.e. the slave address
-public:
-    TXC_rs485(PinName out, PinName in, PinName dir): rs485(out, in, dir) {
-        baud(921600);
-    }
-    void receive(message *m) {
-        state = 0;
-        msg = m;
-        wp = (char*)&msg->hdr.snd;
-    }
-    void send(message *m) {
-#if 1
-        rs485::send((char*)m, BYTES(msg)+7);//use base class for transmission
-#else
-        rpos = 0;
-        msg = m;
-//set RS485 tranceiver in send mode
-        setmode(trans);
-//disable rx interrupt
-        attach(0);
-//enable tx interrupt, will immediately generate int
-        attach(this, &TXC_rs485::tx, TxIrq);
-//kick off transmission
-//  putc((char*)msg)[rpos++];//not necessary, will start by itself
-        rs485_timeout = sizeof(message)/8; //just a precaution, transmit should not timeout, timeout is approx. 110% of expected time
-#endif
-    }
-
-    int Slave(bool clear=false) {//return the destination of the received packet, functions also as reception complete flag, is <0 when not yet available
-        int tmp = tx_message;
-        if (clear)
-            tx_message = -3;
-        return tmp;
-    }
-    void timeout();
-};
-
-void TXC_rs485::rx() {
-//  SETPIN12;
-    char data;
-    do {
-        data = getc();
-        rs485_timeout = 2;//set a timeout of 100-200us equiv. to 10-20 bytes
-        switch (state) {
-            case 0: //idle
-                if (data == 0x02)//stx
-                    state = 1;
-                break;
-            case 1: //stx
-                if (data == 0x55)
-                    state = 2;
-                else
-                    state = 0;
-                break;
-            case 2://length H, high byte comes first
-                msg->hdr.bytesL = data;
-                //length = (unsigned)data<<8;
-                state = 3;
-                break;
-            case 3://length L, low byte
-                msg->hdr.bytesH = data;
-                //length += data;
-                if (msg->hdr.bytes > sizeof(msg)-7)
-                    state = 0; //message structure cannot accomodate message this size
-                else
-                    state = 4;
-                break;
-            case 4://store
-                *wp++ = data;
-                if (wp >= ((char*)&msg->hdr.snd + sizeof(trailer)) + msg->hdr.bytes
-                        && wp <= (char*)msg + sizeof(message) + 1
-                   ) { //message complete
-                    wp = (char*)&msg->hdr.snd;//ready for next message to receive
-                    rs485_timeout = 0;
-                    tx_message = msg->hdr.rec - 3;//slave address tx_message==0 means Ext.1 etc
-                    if (tx_message >= 0) {
-                        attach(0); //disable rec to avoid corruption by new messages
-                    }
-                    state = 0;
-                }
-                break;
-            default:
-                break;
-        }
-    } while (readable()); //see if another char is available, now it is fast enough so this is normally not the case
-//  CLRPIN12;
-}
-
-void TXC_rs485::tx() {// SETPIN12;
-    if (rpos > BYTES(msg)+7) { //last byte was sent
-        attach(0, TxIrq); //disable tx int
-        attach(this,&TXC_rs485::rx, RxIrq); //re-enable rx int
-        rs485_timeout = 0;
-    } else//send 1 byte too many in order to detect that the etx char was sent
-        putc(((char*)msg)[rpos++]);
-// CLRPIN12;
-}
-
-void TXC_rs485::timeout() {
-    //SETPIN12;
-    //reset receiver
-    wp = (char*)&msg->hdr.snd;
-    state = 0;
-    //reset transmitter
-    rpos = 0;
-    setmode(rec);
-    attach(0, TxIrq); //disable tx int
-    attach(this,&TXC_rs485::rx, RxIrq); //re-enable rx int
-    //CLRPIN12;
-}