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Trouble with AD7176-2

Question asked by scarlson on Dec 4, 2015
Latest reply on Dec 8, 2015 by scarlson

Hi All,

 

I just obtained the A7176-2 ADC.  I have exhaustively read through the data sheet, quick start guide, and looked at the examples at least twice each and I seem to be doing everything correct, but my DOUT is still incorrect. 

 

First I want to say.. I found out there was a broken trace connecting the whole right side of the board to power and ground..  I have a new one on order but it won't be here for over a week and from the chip's response I think it is OK.. and this is extremely time sensitive.

 

Below is the output.  I have used the no-OS code first calling the AD7176_Resest() and then the AD7176_Setup() functions.  All I see after the reset from DOUT is 1's.. or just DOUT high.  The screenshots are below.

I want to also point out that I have tried the same method, while instead of calling the no-OS functions just trying to see the device ID by writing 0x47, and I get either gibberish (inconsistent pulses) or nothing.


I have hooked the ad7176-2 up as per pg. 18 of the datasheet with GPIO0/1 grounded.


The scope shows the over all signal, on top, and the zoomed in signal for each part not highlighted in the top signal.


CS -> Yellow

DOUT -> Cyan

SCLK -> Purple

DIN -> Blue

 

What could I be doing wrong? I must be missing something..

 

Any help/recommendation is appreciated.

 

-scott carlson

 

first scope.pngsecond scope.pngthird scope.png

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