Can I use PDM mikes with the 1701 eval kit ?

Thanks Brett,

I looked for that ADAU7002, and it seems there's a eval board... EVAL-ADAU7002Z

only I couldn't see any details for that eval kit on the analog.com site

That board may be helpful to me.

thanks Dennis

Unfortunately, no, you can't directly connect a PDM signal to the ADAU1701, because there is no way to access the decimator independently of the ADC. You will only be able to use an analog mic or I2S-output mic.

Another option would be to stick an ADAU7002 I2S-to-PDM converter in the middle of the PDM microphones and the ADAU1701. More info here: http://www.analog.com/en/audiovideo-products/sample-rate-converters/adau7002/products/product.html

It's a very new product so there might not be any boards in stock, but I will check with the engineer responsible for supporting that product to see what is available.

It turns out that we are out of stock at the moment and expect boards to be available within two weeks or so.

Thanks Brett... it has been a month now, and I just checked the availability of EVAL-ADAU7002Z... still not listed.

Could you check locally to see when these might be available, please.

An indication of price would also be appreciated.

Thanks

Dennis

Hi Dennis,

Sorry that it took me a week to respond. I was on vacation last week and I just returned to the office today.

It appears that Digikey has some of these boards in stock: http://www.digikey.com/product-detail/en/EVAL-ADAU7002Z/EVAL-ADAU7002Z-ND/3991573

I realize that the evaluation board is not on the www.analog.com webpage at the moment. We are working to resolve this.

Thanks Brett for the response.

The Digikey price seems over the top ! why do they include a USBi which has no use for this convertor board?

I'm hoping the AD offering of just the EVAL-ADAU7002Z will be reasonably affordable.

How long do you estimate, before I can order from AD ?

Thanks,

Dennis

The engineer responsible for this board is on vacation this week. I'll try to get that information when he returns next week.

Hi Light1,

You can purchase the EVAL-ADAU7002Z for $89 on the ADI website. You can find it here.

www.Analog.com/ADAU7002

Regards,

-Bill

Many Thanks Bill,

I immediately made a purchase... can't wait to tryout.

Dennis

Hi Brett and others, and thanks for your assistance thus far.

I did purchase the EVAL-ADAU7002Z (2, in fact) and over the last 2 days have been attempting to interface my 2 eval 521Z PDM mikes, the EVAL-ADAU7002Z, and my eval 1701 miniz.

I have not been successful in doing so... no sound at my headphone jack (no problem when i supply a line in analog signal)

I'll be borrowing an oscilloscope in a few days to troubleshoot, but for now, could someone at Analog please try that setup and confirm it does work?

The 7002 operates only in slave mode.. do I need more than LRCLK, BLCK and SDATA and earth connections from the eval7002 to my eval1701?. my connection is about 6 inches, and i take an earth with each signal.

My PDM mikes are working fine (with my other eval kit 1781)

I'm using schematic inputs 2 and 3 in conjunction with the digital inputs SDATA

Have i missed something obvious? I have no other i2s source to try.

Thanks in advance,

Dennis

additional to my last question...

I think I'm coming to understand this now..

I have to "hack" the board a little, remove D4 and D6 LEDs and connect LRClk_out to LRClk_in, and BClk_out to BClk_in.. at least that's what i've gleaned from some of the EZ forum questions/answers.

Can I get a definitive answer from an ADI rep on this..I'd really like to get my setup going to appraise it.

Actually,I do have another I2S source.. the 1781 Evalu kit.

I'll give that a try... at least I can prove the integrity. (1701 digital input OK, setup ok)

I'm also seeing the "communication lost" signal. Does that mean my USBi is on the fritz?

Cheers, Dennis

Success,

I routed the slave output of the 7002 convertor evalu kit to the dig input on my 1781 evalu board... no problem, I have a stereo I2S signal.

So my mikes and 7002 convertor board are good.

Now to do the Hack on the 1701 Board..

looks like remove D4 and D6, lay wire across R33..which gives me MP10, and route to LRCLK, and lay a wire across R14 which gives me MP11, and Route to BCLK..appropriate settings of MP's in registers..

...is that correct?

Dennis

Hi Dennis,

That looks correct to me. Any luck with that configuration?

BR,

Coleman

Hi Dennis,

Sorry for the lack of response. Bill is actually traveling on business.

Yes, to hack the ADAU1701 mini board you should remove the LEDs and gain access to the two multipurpose pins required for the serial port clocks. Of course, you'll also need to take the I2S signal and connect it to the appropriate pin as well. Make sure to configure the MP pins using the graphical register UI in SigmaStudio, and set the master/slave switch the proper way.

Light1 wrote:

I'm also seeing the "communication lost" signal. Does that mean my USBi is on the fritz?

Are you still getting this error? This should only occur when either the device on the bus is unresponsive or not connected. Otherwise, it could be a sign that there was a communication failure / timeout in the USBi.