ADAU1761 DIGITAL MIC ISSUE
We meet a issue at ADAU1761 digital mic application.
I have build a project recieve digital mic signal successful, but I found the DSP have recieved two channel signal while I just connect single PDM mic, and the signal seems copy from anohter which show in Level detector block.
is the PDM signal channel not depend on LRSEL(PDM MIC)? how to set it avoid single signal copy to another?
attachment is a dsp project, which also come from EZ.
Just need single MIC signal into 1761,any response?
Audio Signal Processors
SigmaDSP Audio Processors
adau1761
Hello Felix,
I opened up your project. The first thing I noticed was that you do not have the digital mic selected. On the Digital Setup tab, Dig Mic In Select is set to ADC.Set it to Mic In. I will post a screenshot showing the correct setting.
I also just noticed that you do not have the HPF engaged, I would recommend you engage it.
Next you should show us a scope capture showing the digital mic signal and the clock so we can see what is going on.
Which digital mic are you using?
Dave T
Dear Dave：
Tks your replay. The attach file project could work well in my EVAL-ADAU1761Z, and the register 0x4019[3] you mentioned show a inaccurate name(mentioned in below link) in Sigmastudio, what the full register name is "ADCs off / MIC in off".
https://ez.analog.com/message/42598#comment-42598
and other register config like HP filter or polarity is not my focus issue, do not effect my
The PDM mic use ADMP421 which match the EVAL-ADAU1761Z. the issue is input a single PDM mic signal, but flow into the DSP signal contains two channel audio stream, and two channel signal was the same audio stream, and I cannot find any other register control MIC except 0x4019 & 0x4008. so could your give some advice?
Hello Felix.Lee,
Sorry for the delay. I have been out of town and I am just getting caught up.
So is this problem still happening?
Dave T
Please log in to reply.