Hi,
I am using a bunch of different sensors (FSRs, photodiodes) with the Teensy 4.1. I am adding this EEG shield to the same teensy: https://www.mikroe.com/eeg-click
Unfortunately, the EEG Click (above) is supposed to be used with a 5V development board. I know that if I hook it up normally (teensy 3.3V to the EEG Click, and teensy ground to the EEG Click, with EEG click output to the teensy analog port), any additional electrical input through the EEG electrodes (such as the EEG signal) will cause the voltage that goes into the teensy analog port to be above 3.3V, which is bad.
So instead, I have hooked up the power and ground from the teensy to the EEG click normally, but I have tried to implement a voltage splitter between the EEG Click output and the teensy analog port. I connected EEG Click output to a 10 Ohm resistor, and then I connected that 10 Ohm resistor to a 10 kiloOhm resistor to Teensy's ground. I clipped between those two resistors and that is where I am connecting Teensy's analog port. The Teensy will *always* be plugged into the computer, which is plugged into a wall power outlet, during use with the EEG Click.
I have three questions on the resulting circuit:
1) In this setup, is the EEG Click drawing more than 3.3V from the teensy?
2) Am I actually successfully preventing more than 3.3V from being fed into the Teensy pins?
3) Is this method going to somehow disrupt teensy's ground and thereby affect the teensy or the other sensors/their readings?
Thank you for any insight!
I am using a bunch of different sensors (FSRs, photodiodes) with the Teensy 4.1. I am adding this EEG shield to the same teensy: https://www.mikroe.com/eeg-click
Unfortunately, the EEG Click (above) is supposed to be used with a 5V development board. I know that if I hook it up normally (teensy 3.3V to the EEG Click, and teensy ground to the EEG Click, with EEG click output to the teensy analog port), any additional electrical input through the EEG electrodes (such as the EEG signal) will cause the voltage that goes into the teensy analog port to be above 3.3V, which is bad.
So instead, I have hooked up the power and ground from the teensy to the EEG click normally, but I have tried to implement a voltage splitter between the EEG Click output and the teensy analog port. I connected EEG Click output to a 10 Ohm resistor, and then I connected that 10 Ohm resistor to a 10 kiloOhm resistor to Teensy's ground. I clipped between those two resistors and that is where I am connecting Teensy's analog port. The Teensy will *always* be plugged into the computer, which is plugged into a wall power outlet, during use with the EEG Click.
I have three questions on the resulting circuit:
1) In this setup, is the EEG Click drawing more than 3.3V from the teensy?
2) Am I actually successfully preventing more than 3.3V from being fed into the Teensy pins?
3) Is this method going to somehow disrupt teensy's ground and thereby affect the teensy or the other sensors/their readings?
Thank you for any insight!