• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 45 subscribers
  • Views 468 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.

ADS1248 RDATA Command

Ibrahima Tandian
Prodigy 20 points
Other Parts Discussed in Thread: ADS1248

Hi

When using the ads1248's RDATA command, I noticed that MSB is being shifted out while I'm sending in the command. Is this normal? If it's not normal how do I prevent this from happening?The chip is setup for AIN1+, AIN0-, Onboard ref ON, PGA of 1, 20SPS, default DRDY mode and 100uA IDAC current.

Please see the pictures

Yellow is Cs

Blue is Clk

Green is Din

Purple is Dout 

 

  • 0
    TI__Guru** 113765 points

    Ibrahima Tandian,

    Every time DRDY goes low, the new data becomes available to the output register unless you give a SDATAC command (stop data continuously).  If you want to read your results you can use an interrupt or poll DRDY to know when new data is available.  The next 24 clocks will output the results.

     If you randomly check your data you can use SDATAC in combination with the RDATA.  When using the SDATAC mode, the results are not automatically updated to the output register and you must use the RDATA command to retrieve them.

    Best regards,

    Bob B

  • 0 in reply to Bob Benjamin
    Prodigy 20 points

    Hi Bob

    Thanks for the answer, we used to send RDATA whenever we get DRDY(START was held high all the time). I understand now sending RDATA command is redundant once DRDY goes low.