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.

  • Resolved

[FAQ] ADS129x: I'm having trouble communicating with my ADS129x device via SPI. What debug steps I should try?

Mastermind 19280 points

Replies: 1

Views: 1040

I'm having trouble communicating with my ADS129x device via SPI. What debug steps I should try? 

Best regards,

Alex Smith
Applications Engineer | Precision Delta-Sigma Converters

Check out our helpful resources: BIO-FAQ: Common Questions for TI's ADS129x Family of Bio-Potential ADCs

TI Precision Data Converters | TI Precision Labs - ADCs | Analog Engineer's Calculator Data Converters Learning Center | Selection Guide

  • If the MCU is not correctly communicating with the device, consult the Programming and SPI sections of the datasheet to review communication protocol, power-up and communication timing specifications, and pin connections. After reading the datasheet, review the steps below to find the root cause of the issue.

    Review the start-up sequence and initial flow at power up (section 10.1.2 and 11.1 for the ADS1298). Some step-by-step checkpoints and common debug issues are below:

    1. After the power-on reset is complete, /DRDY should begin pulsing at the default data rate (assuming the START pin is pulled up).
    2. The /RESET pulse after tPOR is essential for bringing up the digital core in the correct state.
    3. Check your CPOL and CPHA settings as shown here.
    4. Before trying to read the registers, make sure to send the SDATAC command.
    5. Read the ID register. If the ID register does not read back correctly, most likely there is an issue with the power-up timing. Go back to the previous steps and make sure that the power supplies have had sufficient time to power up before attempting to communicate with the device. An example of reading the ID can be shown below:
    6. Attempt to write registers and correctly read them back.
    7. Attempt to read data from a known input signal to confirm correct communication and code to voltage conversion.

    Link to BIOFAQ homepage

    This post applies to This post applies to ADS1191ADS1192ADS1291ADS1292ADS1292RADS1294ADS1294R, ADS1296ADS1296RADS1298,   ADS1298RADS1299-4ADS1299-6, and ADS1299.

    Best regards,

    Alex Smith
    Applications Engineer | Precision Delta-Sigma Converters

    Check out our helpful resources: BIO-FAQ: Common Questions for TI's ADS129x Family of Bio-Potential ADCs

    TI Precision Data Converters | TI Precision Labs - ADCs | Analog Engineer's Calculator Data Converters Learning Center | Selection Guide

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.