I wanna measure sinewave frequency which is acquired from soundcard using AmpPhaseSpectrum() .
But the resolution is +/-50,eg.the input frequency is 920Hz,the measurement is 900Hz.
The belowing is the part of my rountine.
Tempdata[] is the data acquired from soundcard,len is the length.
Can you help check?Or is there other solution to measure?
Thanks
for(i = 0;i < len ;i++)
{
Tempdata[i] = tem[i];
}
status = AmpPhaseSpectrum(Tempdata,len,DISABLE_OPTION,interval/(double)len,amp,phase,&df_Amp);
for(i = 2; i<(len/2);i++)
{
if(amp[i] > amp[j])
{
j=i;
}
}
SetCtrlVal(PANEL,PANEL_FRETESTED,(double)(j*df_Amp/2)); //Display the frequency输入频率
