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ADS8555: DSP Selection for High-Speed Data Collection

Jonathan Yoder
Prodigy 30 points
Part Number: ADS8555
Other Parts Discussed in Thread: TMS320F28335, OMAP-L138

Is there a suggested DSP device for reading from the ADS8555 at maximum speed?  I am attempting to collect data at 500ksps and store it on a uSD card. 

I have been trying to read the AtoD using the digital pins on a Raspberry Pi 3B for parallel communication.  With this method I have been able to collect data at about 300ksps, but this hasn't been very reliable.  I believe this is because I cannot control the timing of the digital IO pins precisely enough with the Pi, and I have therefore begun looking into DSPs that I could use. 

In the design document: http://www.ti.com/lit/an/slaa554/slaa554.pdf I saw that a TMS320F28335 was being used to read from the converter, but the conversion rate used was only 2.4ksps, and looking at the clock speed of that device I don't expect that it could collect data at 500ksps.

Is there a specific DSP or family of DSPs that is recommended for reading the ADS8555 at a rate of at least 500ksps.  Ideally the device could interface with either a uSD card for direct storage or with another processor that could handle the storage.

Thank you,

Jonathan Yoder

  • 0
    TI__Guru**** 180961 points

    Hi Jonathan,

    Welcome to our e2e forum!  We have quite a few different processor families here at TI that could operate the ADS8555 at its maximum 500kSPS data rate.  The application note you referred to was just a specific example of how to use the ADS855x devices with relaxed input drive requirements when using slower operating speeds.  In the end, the choice of processor is more a function of what the overall system is supposed to do.  For example, the C2000 family of controllers are focused mainly on motor control applications.  We also have the C5000 and C6000 series DSPs which have significantly more processing power and a wider range of peripherals.  What sort of application are you looking at here?  With a little more detail from you, we might be able to point you to the ideal processor family.

  • 0 in reply to Tom Hendrick
    Prodigy 30 points

    Thank you for the prompt response.

    I am trying to use the ADS8555 to record four different microphones simultaneously.  The data of interest is related to ultrasonic noises, so a sample rate of 500ksps on each channel is needed. 

    There is not an issue with reading from the AtoD the whole time that the processor is running, but due to storage space limitations I would like to be able to control whether data is stored using a digital signal coming from another device.  Ideally each 1-5 second storage "event" would have its own file.

    The data does not need to be processed or modified at all on-board, I am simply looking for a controllable way to transfer data from the output of the AtoD to a nonvolatile storage location where it can be accessed later.

    Thank you again, let me know if I can provide any more specific information,

    Jonathan Yoder

  • 0 in reply to Jonathan Yoder
    TI__Guru**** 180961 points

    Hi Jonathan,

    Take a look at the OMAP-L138 Development Kit (), that might do everything you need.

  • 0 in reply to Tom Hendrick
    Prodigy 30 points

    Thank you very much for the help, I will look into that development kit.

    Jonathan Yoder