Replies: 2
Views: 58
Part Number: ADS1298
Hello,
I have developed my own custom ADS1298 PCB board (for measuring EMG), this PCB is connected to my Arduino DUE. Using my Arduino code (see below), I can read and program the registers of the ADS1298, I read the ID register is 0x92 and can change the sampling frequency to 1kHz and can turn channels ON and OFF (i have enabled channel 3,5 and 7, other channels are turned OFF). Thus this confirms that the chips is working and the power-up sequence is correct. I even tested this code with the ADS1298FE_ECG kit and it worked fine, so the code is correct.
The problem that I have is that I the ADC register values on my custom PCB are fixed at 0x7FFFFF when I read the data on a DRDY interrupt and the channel data doesn't change its value. Does anybody know why this happens?
Thanks,
Oliver
Link to Arduino Due code to read data (ID and register values):
https://github.com/oliverkersten/Graduation-project-files/tree/master/Software%20(firmware)/Arduino%20IDE%20ADS1298%20Test%20Code%20Arduino%20DUE
Link to my Schematics:
https://github.com/oliverkersten/Graduation-project-files/tree/master/Hardware/HD-SEMG%20prototype%20V2
Hi Oliver,
Please check your code to voltage conversion using the BIOFAQ located here: https://e2e.ti.com/support/data-converters/f/73/p/772058/2855202
Best regards,
Alex SmithApplications 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
I have interfaced ADS1298R with STM32L4 and was able to read ECG electrode signals successfully.
ensure the ADC supply voltages are correct as per the datasheet.
you can try first reading the ADC channel registers output by shorting the channel input ( internally check register configuration).
in next step you can try with a battery of fixed voltage.
in these two steps you should get convincing values.
0x7FFFFF means channel input voltage has reached ADC ref voltage in case of bipolar supply
let me know if this fixes the issue.
Veera