SPI1 Analog Devices AD7980 ADC problems

[ahoek]

Posted on April 14, 2008 at 09:57

SPI1 Analog Devices AD7980 ADC problems

[ahoek]

Posted on May 17, 2011 at 12:29

Hi,

Trying to talk to an Analog Devices AD7980 ADC using SPI1.

Everything looks ok on the logic analyzer, but I'm not receiving any data on the MISO line.

Does anybody have experience with these devices? I'm at my wits end.

I use the library functions to set the SPI1 port up as a 16-bit master and handle the SS pin in hardware.

Will post code if someone can help.

Thanks

[ahoek]

Posted on May 17, 2011 at 12:29

Thanks Ivan,

Have you worked with this device before?

It is indeed a strange interface, and there are various configurations possible.

I also find the documentation a bit skimpy, unfortunately I'm taking this project over from someone else and I have to get the current hardware working.

Any pointers/sample code/ docs would be greatly appreciated.

Regards,

André

[ivanov-i]

Posted on May 17, 2011 at 12:29

Hi ahoek,

This part has a little-bit strange usage of the SPI signals. The signal, which is labeled as SDI, is in fact the chip select signal. It must be tied high in order to receive the data stream.

The CNV have to be pulsed before that to perform the conversion.

Regards,

Ivan

[ivanov-i]

Posted on May 17, 2011 at 12:30

Hi Andre,

I didn't use it, but I came to it in the past when I searched for a suitable ADC part. Finaly, I decided to use a chip from TI.

Regards,

Ivan