Tool/software:
Hello,
We are using the ADS1298 and are having some issues with implementing leadoff detection.
We set up leadoff detection for DC, using the threshold of 95% and 5%, 12nA, and pullup/down mode.
We are finding that the EEG signal is no longer usable in this configuration, which is doubly unfortunate because the leadoff works great. Is this to be expected? Our input conditioning is just an RC LPF. Is there something else we can try?
Here is the schematic for the EEG:
Here is the code that sets all the ADS registers:
ADS_WREG(CONFIG1, 0x46); //No daisychaining, low power mode, no clock output, 250Samples/s
ADS_WREG(CONFIG2, 0x00); //not using test signal, turn all off
ADS_WREG(CONFIG3, 0xCC); //internal reference, no RLD
ADS_WREG(LOFF, 0x17);
for (int i = 0 ; i < NUMBER_OF_ADS_CHANNELS ; i++)
{
ADS_WREG(CH1SET + i, 0x10); //Gain of 8, normal operation for all channels
}
ADS_WREG(BIAS_SENSP, 0xFF); //bias correction on
ADS_WREG(BIAS_SENSN, 0xFF); //bias correction on
ADS_WREG(LOFF_SENSP, 0xFF); //All on
ADS_WREG(LOFF_SENSN, 0xFF); //All on
// ADS_WREG(LOFF_FLIP,0xFF);//All flipped
ADS_WREG(GPIO,0xF0); //led on
ADS_WREG(MISC1,0x00); //not using any functions related to misc1
//skip RESP, defaults ok
ADS_WREG(CONFIG4,0x00); //No respiration detect, one-shot mode, LOFF Comp enabled
//skip WCT1 and WCT2
