ADS1299EEGFE-PDK: DRDY does not pulsate with external power source

Anonymous

Part Number: ADS1299EEGFE-PDK
Other Parts Discussed in Thread: ADS1299

Hello,

I'm just trying to replace the MMB0 board with an external power source.
Normally the evaluation board starts pulsing at DRDY, as described in the datasheet, when I use the MMB0 board. However, if I use an external power supply (5V, 3.3V and 1.8V (I know, not absolutely necessary)), DRDY is always HIGH... What could be the reason? Does the MMB0 board do anything else, except the power supply, if I only use the barrel jack?
The test points all have the correct voltages according to the data sheet...
I know that DRDY has to pulsate to communicate with the ADS1299.

Many thanks in advance!

over 6 years ago

0 Anonymous over 6 years ago

Sorry, I solved it myself...

0 Alexander Smith over 6 years ago in reply to Anonymous

TI__Guru 55152 points

No worries Hendrik! Let us know if you have another issue, but expect delays this week as it's about to be a holiday in the US!

0 Anonymous over 6 years ago in reply to Alexander Smith

Hey Alex,

then I actually have one more question.
Is it possible to read the ID register via the software for the evaluation board "ADS1299ECG-FE Evaluation Software"? I didn't see a command to do this, but I'd like to see it on a digital oscilloscope.

Thanks!

0 Alexander Smith over 6 years ago in reply to Anonymous

TI__Guru 55152 points

Hi Hendrik,

The device ID is readable in the register map table, but unfortunately there is not a command to read the ID from the EVM GUI.

Here's an example of what the communication looks like: https://e2e.ti.com/support/data-converters/f/73/t/101941

0 Anonymous over 6 years ago in reply to Alexander Smith

Hi, Alex,

thank you that helps me a lot!
Could it be that I have a problem with the communication with my ADS1299 because I can't transfer 24 bits without gaps? See the pictures... one was taken with the TI software, the other with an Arduino. Whereby this seems wrong to me with the Arduino.

0 Alexander Smith over 6 years ago in reply to Anonymous

TI__Guru 55152 points

Hi Hendrik,

You can see the timing requirements for the SCLK interface in section 7.6 of the datasheet.

It looks like your SCLK frequency is not very stable as the duty cycle changes from pulse to pulse.

Data converters

Data converters forum

ADS1299EEGFE-PDK: DRDY does not pulsate with external power source