src/part2/examples/local/rf/tests/talk.c

/*
 *  ======== talk.c ========
 */
#include <xdc/runtime/System.h>
#include <local/rf/Radio.h>
#include <local/rf/Bsp.h>

#define MINPERIOD   1
#define MAXPERIOD   1000

uint16_t            sMsgPeriod = 100;
static uint8_t      sTxTid = 0, sRxTid = 0;
static Radio_LinkId sLinkID1;

static void     linkTo(void);
static uint8_t  sRxCallback(Radio_LinkId);  /* UART Rx frame handler. */

/*
 *  ======== main ========
 */
void main(void)
{
    Radio_Addr lAddr = {0x77, 0x56, 0x34, 0x12};

    /* This call will fail because the join will fail since there is no Access
     * Point in this scenario. But we don't care -- just use the default link
     * token later.
     *
     * We supply a callback pointer to handle the message returned by the
     * peer. 
     */
    Radio_start(sRxCallback, &lAddr);
    
    /* turn on LEDs. */
    if (!Bsp_led(2)) {
        Bsp_toggleLed(2);
    }
    if (!Bsp_led(1)) {
        Bsp_toggleLed(1);
    }
    
    /* wait for a button press... */
    System_printf("waiting for any button ...\n");
    for (;;) {
        if (Bsp_button(1) || Bsp_button(2)) {
            break;
        }
    }
    
    /* never coming back... */
    linkTo();
    
    /* but in case we do... */
    System_printf("oops!\n");
    System_exit(1);
}

/*
 *  ======== linkTo ========
 */
static void linkTo()
{
    uint8_t  msg[2], delay = 0;
    
    /* wait for peer to link to us */
    System_printf("linking ...\n");
    while (Radio_SUCCESS != Radio_link(&sLinkID1)) {
        /* blink LEDs until we link successfully */
        Bsp_toggleLed(1);
        Bsp_toggleLed(2);
        Bsp_delay(1000);
    }
    
    /* we're linked. turn off red LED. received messages will toggle the
     * green LED.
     */
    System_printf("linked to %d.\n", sLinkID1);
    if (Bsp_led(2)) {
        Bsp_toggleLed(2);
    }
    
    /* turn on RX. default is RX off. */
    Radio_setRxOn();
    
    /* put LED to toggle in the message */
    msg[0] = 2;  /* toggle red */
    while (1) {
        Bsp_delay(sMsgPeriod + (delay * sMsgPeriod));
        
        /* delay longer and longer -- then start over */
        delay = (delay + 1) & 0x07;
        
        /* put the sequence ID in the message */
        msg[1] = ++sTxTid;
        Radio_send(sLinkID1, msg, sizeof(msg));
    }
}

/*
 *  ======== sRxCallback ========
 *  handle received frames.
 */
static uint8_t sRxCallback(Radio_LinkId port)
{
    uint8_t msg[2], len, tid, delta;
    
    /* is the callback for the link ID we want to handle? */
    if (port == sLinkID1) {
        /* yes. go get the frame. we know this call will succeed. */
        if ((Radio_SUCCESS == Radio_receive(sLinkID1, msg, &len)) && len) {
            /* Check the application sequence number to detect
             * late or missing frames... 
             */
            tid = msg[1];
            delta = tid - sRxTid;
            if (delta != 1) {
                System_printf(
                    "frame error: prev = 0x%x, received = 0x%x, sent = 0x%x\n",
                    sRxTid, tid, sTxTid);
            }
            if (tid) {
                if (tid > sRxTid) {
                    /* we're good. toggle the LED specified in the message */
                    Bsp_toggleLed(msg[0]);
                    sRxTid = tid;
                }
            }
            else {
                /* the wrap case... */
                if (sRxTid) {
                    /* we're good. toggle LED in the message */
                    Bsp_toggleLed(msg[0]);
                    sRxTid = tid;
                }
            }

            /* drop frame. we're done with it. */
            return (1);
        }
        else {
            System_printf("receive from %d (len = %d) failed.\n",
                sLinkID1, len);
        }
    }
    
    /* keep frame for later handling. */
    return (0);
}

/*
 *  ======== uartRxCallback ========
 *  SysUart callack function specified in config file
 */
void uartRxCallback(char *buf, int len)
{
    switch (buf[0]) {
        case '-': {
            sMsgPeriod -= 10;
            break;
        }
        case '+': {
            sMsgPeriod += 10;
            break;
        }
        case '0': {
            sMsgPeriod = 0;
            break;
        }
        default: {
            break;
        }
    }

    if (sMsgPeriod < MINPERIOD) {
        sMsgPeriod = MINPERIOD;
    }
    if (sMsgPeriod > MAXPERIOD) {
        sMsgPeriod = MAXPERIOD;
    }
}