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1777 Refuses to Output or Recognize Input when using Microcontroller

Category: Hardware
Product Number: ADAU1777


I am an engineering student working on senior project. We have followed the user manual and set up a project and it displays active and downloaded. No matter what we do we cannot measure any output nor input and can't hear any output from the 3.5mm outputs. We have used the bypass and it works just fine, but when we try to use anything on the board it will not have any noticeable or measurable output or input. We even directly attached the input to the output in our program and it measured nothing on either end. We have tried multiple microphones and speakers and each 3.5mm output/input on the board. Could we please get some help on how to get input and output from the adau 1777. Our end goal is a simple ANC system using phase control.


  • Hello Ethan,

    We could use a few more details. Tell us exactly what you are using for inputs and outputs. What are they connected to? What cables are you suing and how are they wired? 

    Take some more pictures up close so we can see more details on the board. It would be good to be able to see jumper positions and switch positions etc. 

    What is the IOVDD voltage set to on the eval board and the setting on the USBi? the USBi setting is on the bottom. 

    There is a chance you may not be communicating at all with the board. Is the power jumper set to get power from the USBi? Because I see you do not have the external power connected. 

    Then VERY important. Please attach your project. There are so many register settings and signal flow options in this part that we can check quickly with a project but we would spend weeks on this thread going through all of them. 

    Have you looked at anything with an oscilloscope? Have you checked that you have power with a volt meter? 

    The fact that you have some signal when you have the bypass switch in the bypass position helps to answer the question that you probably have the wiring correct. 

    When you attempt to program it watch the Capture window. 

    I suggest you go to the register window and in the Read/Write window try to read a register and see what you get back. You might get back all zeros or all "FFF" (ones) if you do not have power or you are not talking to the part. There is also the I2C/SPI address settings. 

    See if you can "talk" to the part. When I have difficulty I often find it is because I forgot to apply power to the part. Not that I would ever make that mistake! Slight smile


    Dave T

  • Thank you for the reply. We are using simple mono microphones through the stereo input and headphones through the stereo output. As said before, the system works just fine with the bypass on. We are first trying to get simple I/O through the microprocessor.

    The IOVDD voltage is set to 3.3v and the power jumper is set to usbi as far as we can tell.

    We have not checked anything on an oscilloscope yet, we are just trying to get input from microphones and output them through headphones both are connected through the 3.5mm stereo jacks.

    We checked the capture window and didn't get anything.

    We checked the registers and we saw some had zeroes and some had data in them like 0x65 for example.

    If you could possibly send a simple project that is known to work, we would appreciate it. It really should be us that is the issue, but considering we followed the user manual we are confused on how we cannot even get output. I imagine you may not want to send us a project though and that is okay.

    I have attached our project and hope to hear from you soon, we appreciate the help.




  • Hello Ethan,

    I have not had the time to open up your project yet but thanks for sharing it.  A couple of things I noticed. First is that you have the eval board set in Bypass mode. Slide that big switch over to the ON position. The second thing I noticed is that the blue LED on the USBi is on. This is the "Error" LED. This would be why you see nothing in the capture window. Look at the config page of SigmaStudio and see if the icon for the USBi is green?  It will look something like this:

    This may be because the part does not have power and the switch is in bypass. I do not have an eval board to test this. I have alerted the person who supports this part but he has been busy with other fires to put out. 

    To get the USBi out of this mode you will have to unplug the USB cable and reinsert it. 

    Dave T