Communication with ADAU 1701
Hello,
I'm working with the ADAU 1701. According to the data sheds I've built up a circuit quite similar to that of the EVAL-ADAU1701MINIZ. Mostly some elements of the evaluation board are just left out.
After building a prototype board with my circuit on it I've tried to communicate with the SigmaDSP through SigmaStudio - but without success. I'm unable to write to or read from the registers. On the opposite side is a full communication with the EEPROM possible.
So I've started do check the board for failures and also compared the voltage on every pin of the ADAU1701 on my board with that on the evaluation board. So I managed to locate some failures and fixed them. But without further success concerning the communication problem although the voltages are similar right now.
While I don't have that much experience on the field of micro controllers I'm writing here cause I don't have an idea how to continue.
Is there anything important to initialize the ADAU1701 what I could have missed?
Is there a certain way how to check if the ADAU1701 is defect or not? Maybe by measuring the voltage on a special pin or looking at the signal with an oscilloscope during a special state like powering up the board?
I would be thankful for any type of help!
Greetings Thomas
Audio Signal Processors
eeprom
microcontroller
sigmastudio
SigmaDSP Audio Processors
evaluationboard
SigmaDSP
adau1701
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Thomas,
It may be helpful for you to post the schematic of your board for review. On the software side, are you using the USBi board to interface between SigmaStudio and your hardware?
Here is the schematic of the board.
The open Pads are connected to a 15-W filter-free stereo class-d audio power amplifier from Texas Instruments (http://focus.ti.com/lit/ds/symlink/tpa3110d2.pdf) with its own surrounding. I don't believe that there is an influence on the communication with the SigmaDSP from this part of the board, so i left it away in the schematic i've posted here.
Yes, I'm using the USBi board and SigmaStudio from analog devices which i've got together with my evaluation board.
Greetings
ADAU1701 pin 2, ADC1 is shown connected directly to ground; this is not correct. This pin is biased at 1.5 V and if it's unused it should be left disconnected. Grounding it will likely disable all of the analog inputs and outputs, as these are all biased from the same source.
I also see that you have header J1 for connecting the USBi's SDA and SCL signals. Does this connector also have a ground pin to connect to the USBi's ground? Without that, you may not have a reliable data connection between the two boards.
Okay...that failure with the ADC-Input I didn't know. I thought it would be better to give this pin a defined value rather than to leave it open. But that should be fixed very easily and shouldn't have an effect on the programming connection, or?
Yes I'm using J1 for the data connection. We've build a bridge between our prototype board and the USBi so their grounds are connected in the meantime (This pin has to be implemented in the next design) But also with that i can't enable a connection to the SigmaDSP.
The question is: Why am I able to communicate with the EEPROM but not with the SigmaDSP and how can i reassure myself that the ADAU1701 is working.
Greetings
When you say that you cannot communicate with the SigmaDSP, do you mean that you are not receiving an acknowledgement to the I2C address? ARe you writing the first byte of the I2C transaction (including the address), as shown in Table 15 of the ADAU1701 datasheet?
Are you sure that the ADAU1701's oscillator is starting up properly? Do you see a 12.288 MHz clock on the master clock input pin? If you have this clock, you should try to write a test byte to one of the control registers, and then read that byte back to see if you get back what you originally wrote.
I mean that i can't read or write to any specific register as you suggested. Mostly I've tried to test it with the register 1023 with the help of the read/write window for the ADAU1701. That works without problems with the evaluation board.
The Oscillator seems to work properly. I have a the right master clock on the input pin.
How can i receive an acknowledgment to the I2C address? Better to say: Where is it shown?
I don't know how to exactly write the first byte by myself. The only way i know until now is to set the address in the hardware configuration tab in sigma studio. According to tab 16 and my circuit i've set it to 0x68. But so I can only influence the address and nothing else of the bit. I thought SigmaStudio will set the first byte automatically as necessary.
Greetings
If you are writing commands directly from SigmaStudio using the USBi to your hardware, and this setup is working on the evaluation board, then the problem seems to be on your board. Have you checked that the I2S signals look good (clean digital transitions at the correct voltage)? You may also want to swap out the ADAU1701 IC on your board for a new one. Since some of the pins were initially incorrectly connected on your board, there's a possibility that the IC itself was damaged.
Okay, so it seems that i have to swap the DSP. I hoped there is a clear way to check the IC and see rather it is damaged or not before exchanging it.
I will build up a new board with the knowledge i have now and hope this will function.
Greetings.
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Thank you,
EZ Admin
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