• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 47 subscribers
  • Views 2926 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

ADS7280

Rodrigo Ladeira
Intellectual 360 points
Other Parts Discussed in Thread: ADS7280

Hi...

 

I have configurate the ADS7280 with the simple code below:

 

SEL_AD = 1;          //FS/CS
delay_us(1);
START_AD = 1;    // CONVST
delay_us(1);
SCK = 0;
delay_us(30);
SEL_AD = 0;
delay_us(30);
SDO = 1;
delay_us(10);
for(i=0;i<4;i++){
     SCK = 1;
     delay_us(30);
     SCK = 0;
     delay_us(30);
 } 

SEL_AD = 1;

This configution is for load CFR with default mode, but when I read the CFR I recieve this bites: 0x0DFC. I think that the result is wrong. but I dont know why.....

  • 0
    TI__Guru**** 176351 points

    Hi Rodrigo,

    This looks like you are basically writing correctly to the device (data valid on falling SCLK, FS/CS = 0, CONVST = 1).  What happens when you pulse CONVST?  Does the BUSY signal go active?

  • 0 in reply to Tom Hendrick
    Intellectual 360 points

    Hi Tom,

    The ADS7280 do not have the Busy pin, but the pin EOC, when I put CONVST = 0 the EOC signal go low and go high after 1us, the duration of the CONVST low pulse, is 30us.

     

     

  • 0 in reply to Rodrigo Ladeira
    TI__Guru**** 176351 points

    Right, EOC/INT - sorry 'bout that...  OK - so it sounds like the part is basically working.  Using the default register settings, you would be using the internal oscillator for the conversion clock and that would take about 800ns.  Can you try writing something other than the default register values and then attempt to read them back?  I'd be interested in knowing that you can properly write and read data.

  • 0 in reply to Tom Hendrick
    TI__Guru**** 176351 points

    Hi Rodrigo,

    Did you find the problem here?  Were you able to wrtie something other than the defaults and read them back properly?

  • 0 in reply to Tom Hendrick
    Intellectual 360 points

    Hi Tom,

     

    Sorry for take so long to answer.....The problem was the rise and fall time, because I was using a opto-coupler without a digital output....and this information is not present in the datasheet.

     

    Thanks for your help....

     

    Rodrigo (BRAZIL)