利用MAXQ7667确定超声传感器的谐振频率和阻尼特性

　　half_peak = STIM; // save the time it took to reach half the peak value.

　　i = 101; // Half peak found so exit the loop.

　　}

　　while (T2CNB0_bit.TF2 == 0) {} // Wait for timer # 0.

　　T2CNB0_bit.TF2 = 0; // Clear flag.

　　}

　　T2CNA0_bit.TR2 = 0; // Stop timer # 0.

　　return half_peak;

　　}

　　void main()

　　{

　　unsigned short i = 0;

　　unsigned short peak = 0;

　　unsigned short first70 = 0;

　　unsigned short second70 = 0;

　　unsigned short center_pllf;

　　unsigned short wait2measure;

　　unsigned short halfpeak;

　　init();

　　// **********************************

　　// **********************************

　　// Configuration settings

　　echo_receive_gain(0); // Set receiver to minimum gain (allowed values 0-31)

　　Burst_Clock_Divider = 400; // for calculating the burst-frequency in PC-Application.

　　burst_setup(BURST_CLK_PLL, BURST_PULSE_1, BURST_DIV_400, 0, PLL_CLOCK_16MHZ, 0);

　　step_size=10; // Sets the step-size (steps go from 0 to 511).

　　// END configuration settings.

　　// ******************************

　　// ******************************

　　while(1)