Interfacing ADS1298 and nRF52840 via SPI

[gauthamranganathan]

Hello everyone,
I am planning to use the nrf52840 with the ECG sensor ads1298 (AFE for 8 channel ECG). The sensor interfaces via SPI to nRF52840. Has anyone worked on ECG and successfully interfaced these two chips?
The sensor has an internal clock and internal ADC. The maximum SPI clock is supports is 2MHz and has a sampling rate of upto 32KSPS.
Do you see any potential issues I could face?
It would be of great help if anyone shares the driver files
Thank you.

[Turbo J]

Re-read the datasheet of the TI ADS1298. The maximum supported SPI clock is 10MHz.

There is an additional required ADC clock of 2 MHz, but the chip can generate this signal internally.

Running the chip at full 32000 Hz sampling rate requires 8 MHz SPI bus frequency when using the NRF SPIM peripherial (28 byte/sample * 8 bits/byte * 32kHz =  7,168,000 Hz). But the data quality is significantly reduced at high sampling rates - much more noise is present.

I suggest using the chip at its default 500 Hz or 1000 Hz for standard ECG applications, because there will be a lot less noise in the ADC data and you can use lower SPI frequencies.

When using softdevice, you might want to trigger the SPI transaction using GPIOTE input via PPI channel.

[gauthamranganathan]

Turbo J Thanks a lot for your suggestions.