ADS1299: Test ADS1299 with known sine wave signal

Sumit Mourya

Part Number: ADS1299

Hi all,

I have developed my custom ADS1299 Board and till now have been successfully been able to read and write the registers. Also I have tested the ADS with its internal test signal and got a smooth square wave as output.

below are my register values and internal test signal output excel sheet attached.

ADS1299-bridge has started!
111110
Register 0x1 modified.
----------------------------------------------
Register 0x2 modified.
Register 0x3 modified.
Register 0x15 modified.
Register 0x5 modified.
----------------------------------------------
ID	0x00	0x3E	0	0	1	1	1	1	1	0
CONFIG1	0x01	0xD6	1	1	0	1	0	1	1	0
CONFIG2	0x02	0xD0	1	1	0	1	0	0	0	0
CONFIG3	0x03	0xE0	1	1	1	0	0	0	0	0
LOFF	0x04	0x00	0	0	0	0	0	0	0	0
CH1SET	0x05	0x65	0	1	1	0	0	1	0	1
CH2SET	0x06	0x61	0	1	1	0	0	0	0	1
CH3SET	0x07	0x61	0	1	1	0	0	0	0	1
CH4SET	0x08	0x61	0	1	1	0	0	0	0	1
CH5SET	0x09	0x61	0	1	1	0	0	0	0	1
CH6SET	0x0A	0x61	0	1	1	0	0	0	0	1
CH7SET	0x0B	0x61	0	1	1	0	0	0	0	1
CH8SET	0x0C	0x61	0	1	1	0	0	0	0	1
BIAS_SENSP	0x0D	0x00	0	0	0	0	0	0	0	0
BIAS_SENSN	0x0E	0x00	0	0	0	0	0	0	0	0
LOFF_SENSP	0x0F	0x00	0	0	0	0	0	0	0	0
LOFF_SENSN	0x10	0x00	0	0	0	0	0	0	0	0
LOFF_FLIP	0x11	0x00	0	0	0	0	0	0	0	0
LOFF_STATP	0x12	0x00	0	0	0	0	0	0	0	0
LOFF_STATN	0x13	0x00	0	0	0	0	0	0	0	0
GPIO	0x14	0x0F	0	0	0	0	1	1	1	1
MISC1	0x15	0x20	0	0	1	0	0	0	0	0
MISC2	0x16	0x00	0	0	0	0	0	0	0	0
CONFIG4	0x17	0x00	0	0	0	0	0	0	0	0

Now I want to apply a sine wave from function generator before giving the actual EEG signal. Should I only change the Electrode mode to Normal Electrode Input for sine wave input or I need to change other Register Values too?EEG TEST ADS DATA.xlsx

over 5 years ago

0 Sumit Mourya over 5 years ago

Expert 1790 points

Just an Addition to the post My PCB Connections are that Iam using all the (+) inputs as electrode input.

I have short circuit all the (-) Pins of the channels to the SRB1 pin Externally through tracks to the reference electrode input.

BIAS Electrode Input is connected to the BIASOUT Pin of the ADC.

0 Alexander Smith over 5 years ago in reply to Sumit Mourya

TI__Guru 55062 points

Hi Sumit,

Changing to normal electrode input is all you have to do in terms of registers. You may however want to change the gain depending on the magnitude of the provided signal.

Make sure that the signal is within the common-mode limits of the inputs and double-check the absolute maximum ratings table to ensure that the device is not accidental damaged before applying the signal.

0 Sumit Mourya over 5 years ago in reply to Alexander Smith

Expert 1790 points

Hi Alex,

I tested my board with Sinewave, ECG and finally got wonderfull EEG Recording as well.

Now I will test my second ADS1299 In Daisy Chain mode. Hope to get that working too.

0 Alexander Smith over 5 years ago in reply to Sumit Mourya

TI__Guru 55062 points

Great to hear Sumit!

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ADS1299: Test ADS1299 with known sine wave signal