Hi,
I have two questions:
1- If I want to use the audio codec through a poll instead of with intr and my fir filter uses intr functions, can I have two vectors activated at the same time on my project? One vector poll for the audio codec and another intr vector for the fir filter.
2- I want to DAC_ATTEN of the audio codec constantly, how could I do it? Because I tried to use this:
output_sample(buffer[inbuf_ptr]); And I change the values of the array by multiplying them with a number between 0 and 1. But the output audio makes a lot of noise, and I don't get what I want. Any idea?
Also, I've tried to use this code, but I don't know how to set it as a low pass filter with a certain cut-off frequency, neither the coefficients.
float x[N]; // filter delay line
float h[N] = {
2.0000E-001,2.0000E-001,2.0000E-001,2.0000E-001,2.0000E-001
};
interrupt void interrupt4(void)
{
short i;
float yn = 0.0;
x[0] = (float)(input_left_sample()); // input from ADC
for (i=0 ; i<N ; i++) // compute filter output
yn += h[i]*x[i];
for (i=(N-1) ; i>0 ; i--) // shift delay line
x[i] = x[i-1];
output_left_sample((uint16_t)(yn)); // output to DAC
return;
}
Best regards,
Miguel.
