Interfacing multiple SPI ADC's to the BeagleBone Black

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1

Dear support group,

My data logging application requires 32 channels of ADC. I see TI make an 8 channel, 12 bit, 1 MSPS, ADC with a SPI interface (Part no: ADS 8028). The ADC’s are only required to capture data a few times a minute, so each of the ADC’s can be sequentially sampled.

I am not familiar with using the Beaglebone Black or its SPI interface and was wondering if somebody could give me a few pointers in this regard:

  1. Will the Beaglebone Black support this ADC, and multiples of them, 2 or 4 per SPI interface?
  2. Has anybody enjoyed success in using this ADC for this purpose?
  3. If not this particular ADC, then could somebody recommend an alternative. ( I would, if possible, like to stay within the TI family of components. I desire 12 bit resolution, no missing codes, and 100KSPS/channel).
  4. Are any drivers available for the ADS 8028 within any of the Linux distributions (Arch/Angstrom) that run on the BeagleBone?

Any help in this regard would be much appreciated. Thank you
Kind Regards
Snoopy

2

I don’t see any issue using the ADS8028. SPI uses the same control pins and separate SPI CS lines. I don’t think we have four, but you could gate the CS with GPIO pins and get dozens of CS lines, especially at the slow rate you need. You can look at the SRM for more information on the available pins and chip selects.

http://circuitco.com/support/index.php?title=BeagleBoneBlack

Gerald

3

Hi Gerald,

Thanks for your feedback.

4

For that low data rate an analog demux (M74HC4051 or so) might be
simpler to deal with than multiple SPI chips, then you can just use
the onboard ADC and a few digital output from the bone to pick the
channel.

Britton