i.MXRT: Connect external ADC with an interface similar to Dual-SPI

[christian_mauderer]

Hello,

I'm searching for a method to connect a higher precision simultaneous sampling external ADC to an i.MXRT1166 processor. A lot of ADCs in that class seem to use more or less a Dual-SPI. For example, I'll use the ADS8686S in it's 2-Wire serial interface mode: https://www.ti.com/lit/gpn/ads8686s. For that chip, the interface timing is as follows:

So there is more or less a Dual-SPI with one line for data from channel A and one line for channel B. If I connect that to a LPSPI and set that to Dual-SPI, I get data that is mixed bit by bit: One bit from channel A, one bit from channel B, one bit from channel A, ...

I think it might could be possible to do that with the FlexIO. But I'm not entirely sure yet. The FlexIO is a bit complex and I don't have a hardware to try it yet.

Is it possible to get the data from an ADC with an interface like that into the i.MXRT in a sensible way using the FlexIO? Is there a simpler solution?

With kind regards

Christian

[Kan_Li · Accepted solution]

Hi @christian_mauderer ,

Yes, FlexIO can be used for that purpose, and we provide several demos in driver_examples\flexio\spi, you may use either of them as a starting point.

Hope that helps,

Have a great day,
Kan

-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!
- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
-------------------------------------------------------------------------------