File content as of revision 18:19bcb2dbf3c8:

#include "com.h"

//#define DEBUG_COM
#ifdef DEBUG_COM
    #define NL "\n\r"
    #define PRINT(x)        xbee.printf(x)   //Serial.print(x)
    #define PRINTF          xbee.printf   //Serial.print(x, y)
    #define PRINTLN(x)      PRINT(x);PRINT(NL)
    #define START           timerCom.start(); 
    #define STOP            timerCom.stop()
    #define RESET           timerCom.reset()
    #define READ            timerCom.read_us()
    #define GET(x)          x = READ
#else
    #define PRINT(x)
    #define PRINTF(x, y)
    #define PRINTLN(x)
    #define PRINTLNF(x, y) 
    #define START 
    #define STOP  
    #define RESET 
    #define READ 
    #define GET(x)
#endif

com::com(PinName tx, PinName rx): xbee(tx,rx)
{
    xbee.baud(BAUDRATE);
    xbee.attach(this,&com::callback);
}

com::~com()
{
}

void com::callback()
{
    while(xbee.readable())
    {
        char data = xbee.getc();
//        xbee.putc(data);
        rxBuffer.add(data);
    }
}

bool com::isData()
{
    static char packetIndex = 0;
    static char pack_cmd = 0;
    static char pack_value[2] = {0,0};
    static char pack_seq = 0;
    static char pack_checksum = 0;
    
    __disable_irq();
    while ( !rxBuffer.isEmpty() )
    {
        char data = rxBuffer.pop();
        __enable_irq();
//        PRINTF("d: %d \n\r", data);
        switch (packetIndex)
        {
            case 0:
            {
                if ( data == 255 )
                packetIndex++;
                break;
            }
            case 1:
            {
                if ( data < 13 )
                {
                    pack_cmd = data;
                    packetIndex++;
                }
                else
                    packetIndex = 0;
                break;
            }
            case 2:
            {
                pack_value[1] = data;
                packetIndex++;
                break;
            }
            case 3:
            {
                if ( data < 128 )
                {
                    pack_value[0] = data;
                    packetIndex++;
                }
                else
                    packetIndex = 0;
                break;
            }
            case 4:
            {
                pack_seq = data;
                packetIndex++;
                break;   
            }
            case 5:
            {
                short temp = pack_value[0] + pack_cmd;
                pack_checksum = data;
                if ( temp == pack_checksum )
                {
                    short * ackPacket = new short[2];
                    ackPacket[0] = pack_cmd;
                    ackPacket[1] = pack_seq;
                    txBuffer.add( ackPacket ); // Ack the packet with sequence nuber.
                    
                    short * array = new short[2];
                    array[0] = pack_cmd;
                    array[1] = pack_value[1] * 128 + pack_value[0];
                    cmdBuffer.add( array );
                }
                
                packetIndex = 0;
                break;   
            }
            default:
            packetIndex = 0;
            break;
        }
        
        __disable_irq();
        
    }
    __enable_irq();
    return !cmdBuffer.isEmpty();
}

short * com::read()
{
    if ( !cmdBuffer.isEmpty() )
        return cmdBuffer.pop();
    else
        return NULL;    
}


bool com::rdy2ack()
{
    return !txBuffer.isEmpty();
}

void com::sendACK()
{
    if( !txBuffer.isEmpty())
    {
        short * pkt = txBuffer.pop();
        __disable_irq();
        write(pkt[0],pkt[1]); //may need to disable interrupt
        __enable_irq();
        delete[] pkt;
    
    }
}

void com::write( short command, short seq  )
{  
    xbee.putc( 255 );                     // End of message.
    xbee.putc( (char)command );           // Command
    xbee.putc( (char) seq);            // Second 8 bits in array.
    xbee.putc( (char) command + seq );        // Checksum array[0] + array[1].
}