RTOS/ADS1292: ads1292 maxium sample rate to CC2640

user4793539

Part Number: ADS1292
Other Parts Discussed in Thread: CC2640

Tool/software: TI-RTOS

Hi, I set the ads1292 sample rate to 2K, but when I read datas from ads1292, I can only got 1.88K samples.

My design using TI BLE stack and TI-RTOS， I handle the sample data using SPI interrupt . For 1 sample to next sample ready, I only have 500us time to handle.

I guess maybe TI-RTOS task swtich and enter critical section affect the SPI interrupt handle.

so I want to know the maxium sample rate is supported to cc2640 with TI-RTOS and BLE application?

How can I solve the problem?

Thanks!

over 8 years ago

0 Ryan Andrews over 8 years ago

TI__Guru 66446 points

Hello,

Thanks for your question.

I can help answer your questions regarding the ADS1292, but please make a separate thread with our MCU team to inquire about the limitations of the CC2640.

How long are you acquiring data for? If you are collecting for 1 second and do not see 2,000 samples, then you are likely missing data due to an SPI timing issue. Please verify that your SCLK frequency is fast enough to read all the data (STATUS + 2 channels) within the 500us data rate period.

Best Regards,

0 user4793539 over 8 years ago in reply to Ryan Andrews

Intellectual 580 points

Thank you ! It's about 100-120us to read 1 samples, SPI rate is 1Mbps.

0 Ryan Andrews over 8 years ago in reply to user4793539

TI__Guru 66446 points

Your SCLK is certainly fast enough to read the data. I would double-check your SPI timing and make sure that you are monitoring /DRDY properly as an interrupt in your data collection routine.

Best Regards,

0 user4793539 over 8 years ago in reply to Ryan Andrews

Intellectual 580 points

I monitor the /DRDY pin and /CS by OsciiloScope .

The problem has been solved.

Our hardware PCBA caused the problem, I test 3 PCBAs, the others are all work fine.

CC2640 works well for 2K/4K SPS, but when work at 8K SPS, BLE is broken for timeout.

Thanks!

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RTOS/ADS1292: ads1292 maxium sample rate to CC2640