• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 45 subscribers
  • Views 325 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADS8556EVM: Reading from ADS8556EVM in hardware serial mode

TALIA XU
Prodigy 170 points

Part Number: ADS8556EVM

I am trying to read data from ADS8556EVM with a PI in hardware serial mode, I am confused as in how to connect it to the PI, what would be the easiest way to set this up?

  • 0
    TI__Mastermind 45715 points

    Hi TALIA,

    To use hardware parallel mode, you need 16 data bus for DB[15:0], also you need control signals for key signals on ADS8556(CONVST_x, /CS,/RD and BUSY), ADS8556 datasheet has detailed information about required signals to run at different mode. To be simple for you, serial interface will require less signals. See information in other post on this forum:

    https://e2e.ti.com/support/data-converters/f/73/p/545849/2037040?tisearch=e2e-sitesearch&keymatch=ads8556#2037040

    Note that:

    1. Blue wires to connect your controller and the ADC may lead to worse performance, this is not recommended to evaluate the ADC.

    2. ADS8556 needs external high BW and high voltage amplifiers to drive because of switched-capacitor input structure. ADS8588S is recommended if you are designing a new project and do not have a high bandwidth requirement.

    Best regards,

    Dale

  • 0 in reply to Dale Li
    Prodigy 170 points

    Hi Dale,

    Thank you for your response, I am sorry for the typo on the title, I am indeed trying to use in hardware mode and connect it to SPI0 on a PI, however, I couldn't get it to connect.

    I am trying to use all 6 channels in hardware serial mode, the switch positions I have are

    1 ON

    2 ON

    3 ON

    4 OFF

    5 ON

    6 ON

    7 OFF

    8 OFF

    9 OFF

    10 OFF

    I have J1.3 connected to SCLK, J1.7 to CS0, J1.11 to MOSI and J1.13 to MISO in SP0 of a Raspberry PI and tried to use SPI to connect, however, I am not able to get any meaningful data.

    Is there anything wrong with the setup? I left all other jumpers in their default positions. This is the ADS8556 evaluation board by the way.

  • 0 in reply to TALIA XU
    Prodigy 170 points

    Another question - 

    Do the HOLDx (CONVST_A to CONVST_C)  signals have any impact for hardware serial control?

  • 0 in reply to TALIA XU
    TI__Mastermind 45715 points

    Hi TALIA,

    ADS8556 datasheet has provided all information you need, I suggest you to check it firstly.

    1. CONVST_A/B/C are important signals to the ADC, the ADC will not do any conversion without these signals.

    2. Make sure you provided high signal to /STBY pin which is not configured on the EVM.

    3. Make sure unused DBx pins have been connected to the ground on the EVM.

    4. Have you provided all power supplies(AVDD,BVDD, HVDD,HVSS) required to the EVM board?

    Best regards,

    Dale