Hello Team,
We have a custom board with ADS1299 data converter onboard. We are using this chip for measurement of EEG signal.
Following are configurations on the board -
1. Sampling rate - 500SPS
2. DRDY(Bar) signal is configured as hardware interrupt in microcontroller. When interrupt generates, firmware will initiate data read over SPI.
3. GPIO Pins - PWDN (Bar), START, DAISY_IN, RESET(Bar), DRDY(Bar), CLKSEL, CLK and SPI related pins.
We followed the power ON sequence and SPI lines are used only for writing register settings and reading data.
We observed that, after few conversions, DRDY(Bar) signal stops generating from ADS1299. Also, sometimes DRDY(Bar) signal occurs every 4ms instead of 2ms. To diagnose this issue we had added logic in firmware to read register settings after issue occurred.
We found that the registers of ADS1299 are resetting to default values. (While configuring ADS1299 we write CONFIG1 to 0xD5 and after issue observed its value becomes 0x96 which is default value)
We have following questions related to above issue -
1. Are there other ways to verify ADS1299 is getting reset?
2. What could be the reasons ADS1299 gets reset?
3. Are there any conditions/reasons which sets register to their default values other than chip reset?
4. Are there any ways to find chips gets reset due to power supplies?
Your response will help us in diagnosing the issue further.
Thank you.
Best regard,
Nikint Kshirsagar
