File content as of revision 0:24d1bc29e7be:

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#include "mbed.h"

/** magic numbers **/
#define HEADER_ON_TIME 1700     // 1.7[ms]

/** QSTEER COMMAND INTERVALS ON EACH BANDS **/
#define BAND_A_INTERVAL1 130000 // 130[ms]
#define BAND_A_INTERVAL2 8000   //   8[ms]
#define BAND_B_INTERVAL1 115000 // 115[ms]
#define BAND_B_INTERVAL2 25000  //  25[ms]

#define BAND_C_INTERVAL1 90000  //  90[ms]
#define BAND_C_INTERVAL2 50000  //  50[ms]
#define BAND_D_INTERVAL1 70000  //  70[ms]
#define BAND_D_INTERVAL2 70000  //  70[ms]

/** QSTEER CONTROL BANDS **/
#define BAND_A  0x00
#define BAND_B  0x10
#define BAND_C  0x20
#define BAND_D  0x30

/** QSTEER MOVE COMMANDS **/
#define COMMAND_NONE 0x00
#define COMMAND_FWD  0x01
#define COMMAND_BACK 0x02
#define COMMAND_LEFT 0x03
#define COMMAND_RIGHT 0x04
#define COMMAND_FWD_DASH 0x05
#define COMMAND_FWD_LEFT 0x06
#define COMMAND_FWD_RIGHT 0x07
#define COMMAND_FWD_LEFT_DASH 0x08
#define COMMAND_FWD_RIGHT_DASH 0x09
#define COMMAND_BACK_LEFT 0x0a
#define COMMAND_BACK_RIGHT 0x0b
#define COMMAND_BACK_DASH 0x0c
#define COMMAND_BACK_LEFT_DASH 0x0d
#define COMMAND_BACK_RIGHT_DASH 0x0e
#define COMMAND_STOP 0x0f

/** IR LED POWER RATE **/
#define IR_LED_ON_POWER 0.8f
#define IR_LED_OFF_POWER 0.0f

/** input/output pin settings **/
DigitalOut keepAliveLed(LED1); // for Board LED1 (mbed running status)
DigitalOut myled(LED4);        // for Board LED4 (IrLED ON/OFF Status)
DigitalIn  tactSwitch(p8);     // for Switch
PwmOut irOut(p21);             // for IR LED
Serial xbee(p13, p14);         // for XBee
//Serial pc(USBTX, USBRX);     // USBTX - Tranmit on USB  USBRX - receive on USB

/** Variables **/
Timer timer;
unsigned int receivedChar;

/*
 *    IR-LED ON/OFF
 */
void outputSignalInterval(int iTime, bool s)
{
    float signal = (s == false)? IR_LED_OFF_POWER : IR_LED_ON_POWER;
    timer.start();
    int offset = timer.read_us();
    while (iTime > (timer.read_us() - offset))
    {
        irOut.write(signal);
    }
    timer.stop();                        
}

/*
    IR-LED OFF
 */
void outputSignalStop()
{
    irOut.write(IR_LED_OFF_POWER);
    myled = 0;
}

/*
    SEND ON SIGNAL
*/
void outputSignalOn()
{
    outputSignalInterval(500, false);
    outputSignalInterval(800, true);
}

/*
    SEND OFF SIGNAL
*/
void outputSignalOff()
{
    outputSignalInterval(500, false);
    outputSignalInterval(400, true);
}

/*
    SEND TO IR-LED (QSTEER CONTROL)
*/
void sendToIrLED(unsigned char band, unsigned char command)
{
    unsigned char sendCommand = ((band & 0x30)|(command & 0x0f));

    int interval1 = BAND_A_INTERVAL1;
    int interval2 = BAND_A_INTERVAL2;

    int checkBit1 = 0x20;
    int checkBit2 = 0x20;

    myled = 1;

    // DECIDE COMMAND INTERVAL
    if (band == BAND_A)
    {
        interval1 = BAND_A_INTERVAL1;
        interval2 = BAND_A_INTERVAL2;
    }
    else if (band == BAND_B)
    {
        interval1 = BAND_B_INTERVAL1;
        interval2 = BAND_B_INTERVAL2;
    }
    else if (band == BAND_C)
    {
        interval1 = BAND_C_INTERVAL1;
        interval2 = BAND_C_INTERVAL2;
    }
    else if (band == BAND_D)
    {
        interval1 = BAND_D_INTERVAL1;
        interval2 = BAND_D_INTERVAL2;
    }

    // SEND HEADER(1st)
    outputSignalInterval(interval1, false);
    outputSignalInterval(HEADER_ON_TIME, true);

    // SEND COMMAND (1st)
    while (checkBit1 != 0)
    {
        if ((checkBit1 & sendCommand) != 0)
        {
            outputSignalOn();
        }
        else
        {
            outputSignalOff();
        }
        checkBit1 = checkBit1 >> 1;
    }

    // SEND HEADER (2nd)
    outputSignalInterval(interval2, false);
    outputSignalInterval(HEADER_ON_TIME, true);

    // SEND COMMAND (2nd)
    while (checkBit2 != 0)
    {
        if ((checkBit2 & sendCommand) != 0)
        {
            outputSignalOn();
        }
        else
        {
            outputSignalOff();
        }
        checkBit2 = checkBit2 >> 1;
    }

    // IR-LED OFF
    outputSignalStop();
}

/*
 *  
 *
 */
unsigned char decideCommand(unsigned char band, unsigned int value)
{
    unsigned int bandA =  (value & 0x000f);
    unsigned int bandB = ((value & 0x00f0) >> 4);
    unsigned int bandC = ((value & 0x0f00) >> 8);
    unsigned int bandD = ((value & 0xf000) >> 12);  
    unsigned char returnValue = COMMAND_NONE;

    if (band == BAND_A)
    {
        returnValue = (unsigned char) bandA;
    }
    else if (band == BAND_B)
    {
        returnValue = (unsigned char) bandB;
    }
    else if (band == BAND_C)
    {
        returnValue = (unsigned char) bandC;
    }
    else // if (band == BAND_D)
    {
        returnValue = (unsigned char) bandD;
    }
    return (returnValue);
}

/*
 *  Moving command received from HOST
 */
void receivedSerial()
{
    int ch = xbee.getc();
    receivedChar = (unsigned int) (ch & 0xff);
    xbee.printf("[0x%02x]", receivedChar);  // for debug echoback
}

/*
 *
 */
int main()
{
    // set serial speed
    xbee.baud(9600);
    
    // set serial callback function.
    xbee.attach(&receivedSerial,Serial::RxIrq);

    irOut.period_us(26);  // 26[us] == 38[kHz]

    int count = 0;
    float duration = 0.01;
    bool keepAlive = true;
    while (1)
    {
        if (tactSwitch == 0)
        {
            // Ir-LED STOP
            outputSignalStop();
        }
        else
        {
            unsigned int checkValue = 0x0021;
            sendToIrLED(BAND_A, decideCommand(BAND_A, checkValue));
            sendToIrLED(BAND_B, decideCommand(BAND_B, checkValue));
        }

        if (receivedChar == 0)
        {
            outputSignalStop();
        }
        else
        {
            sendToIrLED(BAND_A, decideCommand(BAND_A, receivedChar));
            sendToIrLED(BAND_B, decideCommand(BAND_B, receivedChar));
        }

        if ((count % 64) == 0)
        {
            // flashes led 
            keepAlive = (keepAlive == true) ? false : true;
        }
        keepAliveLed = keepAlive;
        wait(duration);
        count++;
    }
}