Hello all,

For about a month or two now I have been researching various EMG circuits trying to learn what parts were essential for a basic circuit. After I thought I had a pretty good about what I needed to do I sat down and came up with this circuit. I assembled the circuit on a breadboard with a separate dual 5 volt supply on a different breadboard. When I connect it to the analog input of my arduino uno the values are just random, from what I can tell it's all noise. I cannot figure out whats wrong with the circuit, I've tried several things with no success. If anyone could help I would greatly appreciate it.

Thanks,
Anthony

 

What the heck is an EMG? Do you think that we can read your mind? Some of us can, but at this distance, it is pretty dicey.

 

https://en.wikipedia.org/wiki/Electromyography
Can you post a schematic of your circuit? In testing, what are your electrodes connected to?

Ken

 

Because this is a small signal, the wiring is critical to proper operation. The wires must be short and a star grounding system has to be used.

A picture of how you have wired your circuits would help us help you better.

 

I assembled the circuit on a breadboard

That could be the main reason for the noise. Lengthy conductors and stray capacitance/inductance can pick up and couple noise into your circuit. As stated, wiring is critical.

 

I have attached the schematic in my original post. Here are pictures of the actual circuit, I have switched to the Arduino Nano just to make everything more compact.

 

Are those three electrode leads screened?

 

I'm not too sure but I'm going to say they aren't.

 

EMG signals are down at microvolt levels.

You cannot expect to get this kind of low noise performance from a sketchy pile of solderless bread boards.
With RF and microvolt signals, the layout and construction becomes critical to circuit function.

This is where electronics becomes an art, no longer just a connect-the-parts exercise.

 

I'm not too sure but I'm going to say they aren't.

This suggests that even if there are screen conductors you're not using them. A guaranteed source of noise input then .

 

SLK001, please try to control yourself. Your sarcasm and rudeness will not get you anywhere in life!