Original question:
We have used the AIC3111 in our application, for sending audio data over a connection and plotting it on Audacity. However, on Audacity, there's a negative DC Bias in the audio which we would like to do away with. Images for reference are below
In the referenced article, there was a register for the ADC filter, but I couldn't find any such filter on the AIC3111.
Hello Souvik,
All of the processing blocks come with a first order programmable IIR filter. You can set the coefficients to generate a High Pass Filter. The image below shows the information on what registers need to be set.
I have also generated the N0, N1, D1 coefficients for a cutoff frequency of 150Hz. N0, N1, D1 shown below, respectively:
0x7EA9
0x8157
0x7D54
Let me know if implementing this helps with the DC offset.
Regards,
Aaron
Hello Aaron,
I added the values like so :
reg[4][8] = 0x7E
reg[4][9] = 0xA9
reg[4][10] = 0x81
reg[4][11] = 0x57
reg[4][12] = 0x7D
reg[4][13] = 0x54
And this did the trick of removing the dc bias. However, we have used an FIR filter block in the PFW and it seems that it isn't working like before.
