ultrasoundcontrolm.nc

无线传感器网络中的节点定位算法。详见ReadMe文件。在TinyOS上实现的节点定位算法。

/*
 * Cricket Ultrasound Control implementation for TOSSIM.
 * David Moore <[e-mail]>
 */
module UltrasoundControlM {
    provides {
        interface UltrasoundControl;
    }
}
implementation {
    /*
     * Resets the timer that measures the number of microseconds until
     * each incoming pulse of the ultrasound receiver.  The
     * PulseDetected event will be generated for each rising edge of
     * the pulse.  timeout specifies the number of microseconds before
     * the timer is disabled, at which time the DetectorTimeout event
     * is generated.
     */
    async command result_t UltrasoundControl.StartDetector(uint16_t timeout)
    {
        TOSH_us_start_detector(timeout);
        return SUCCESS;
    }

    /*
     * Stops the ultrasound timer and prevents the generation of further
     * events.
     */
    async command result_t UltrasoundControl.StopDetector()
    {
        TOSH_us_stop_detector();
        return SUCCESS;
    }

    default async event result_t UltrasoundControl.PulseDetected(uint16_t timer)
    {
        return SUCCESS;
    }
    default async event result_t UltrasoundControl.DetectorTimeout()
    {
        return SUCCESS;
    }
    /* When the timeout is reached, the timer is stopped and the
     * DetectorTimeout event is generated. */
    void TOSH_us_timeout() __attribute__ ((C)) {
        call UltrasoundControl.StopDetector();
        signal UltrasoundControl.DetectorTimeout();
    }

    /* Upon receiving the rising edge of a pulse, generate an event
     * with the captured time. */
    void TOSH_us_pulse_detected(uint16_t timer) __attribute__ ((C)) {
        signal UltrasoundControl.PulseDetected(timer);
    }

    /* 
     * Generate a 150 us pulse of 40 KHz ultrasound using the transducer.
     */
    async command result_t UltrasoundControl.SendPulse() {
        TOSH_us_send_pulse();
        return SUCCESS;
    }
}