Currently working on an EEG design for an ESP32 microcontroller. This was part of my capstone project, and I am just working on this for fun and to learn more as this was my partners subsystem. I modifying my partners design which was originally on Multisim.
So the first image is the full EEG transient. Which I think the output it incorrect.
Next a notch filter AC sweep which is used twice for the 60 Hz noise.
I went back testing each component finding the differential gain and common mode of the instrumentation amplifier
Differential Mode Gain Ad = 100.4 mV / 1.04 mV = 96.5385 V/V
Common Mode Gain Ac = -489.32µ/0.9927 mV = 0.48932mV/0.9927mV = -0.4929 V/V
Common Mode Rejection Ratio (CMRR) = 20log10(Ad/|Ac|) = 45.8385 dB
This was interesting as in the datasheet for the IC it can reach 110 and I know ideally you want to be at least above 100dB
I am also planning on implementing a voltage regular for the negative 3.3V onto the instrumentation amplifier as the ESP32 can not take negative voltages but I am trying to perfect the amplifier first before so.
I also ran AC Sweeps on my bandpass filter, which I am trying to get the 3-12 and 12-30Hz frequency for alpha and beta waves.
Any advice on anything I'm doing wrong? Still trying to figure everything out and learn.
So the first image is the full EEG transient. Which I think the output it incorrect.
Next a notch filter AC sweep which is used twice for the 60 Hz noise.
I went back testing each component finding the differential gain and common mode of the instrumentation amplifier
Differential Mode Gain Ad = 100.4 mV / 1.04 mV = 96.5385 V/V
Common Mode Gain Ac = -489.32µ/0.9927 mV = 0.48932mV/0.9927mV = -0.4929 V/V
Common Mode Rejection Ratio (CMRR) = 20log10(Ad/|Ac|) = 45.8385 dB
This was interesting as in the datasheet for the IC it can reach 110 and I know ideally you want to be at least above 100dB
I am also planning on implementing a voltage regular for the negative 3.3V onto the instrumentation amplifier as the ESP32 can not take negative voltages but I am trying to perfect the amplifier first before so.
I also ran AC Sweeps on my bandpass filter, which I am trying to get the 3-12 and 12-30Hz frequency for alpha and beta waves.
Any advice on anything I'm doing wrong? Still trying to figure everything out and learn.
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