Hello,
First of all, thanks to Sparkfun for the ECG monitoring board, it’s easy to use and well explained in the tutorial, I loved using it 
The only issue I have is that even a slight movement of the subject induces high variations in the output and unprocessable signals, despite the AD chip datasheet’s promises. I could not imagine integrate this device into a wearable because of that.
Is there anyway I can improve this by changing some values of resistors of the sparkfun board?
Also, maybe a silly question but: why is there so many components on the board? direct plugging onto the pins of the AD8232 would not work at all?
Thanks a lot
The only issue I have is that even a slight movement of the subject induces high variations in the output and unprocessable signals, despite the AD chip datasheet’s promises. I could not imagine integrate this device into a wearable because of that.
Your heart is a muscle and the AD8232 works by receiving weak electrical signals a beating heart generates. If you move, other muscles in your body are also generating weak electrical currents and the AD8232 isn’t able to tell if those are from the heart or another muscle. Unfortunately there isn’t any way around this unless you use a much more sophisticated device ($$$$) to receive these signals and even then, movement will be an issue.
Is there anyway I can improve this by changing some values of resistors of the sparkfun board?
Not really. Changing the resistors would decrease the boards sensitivity and would filter out the heartbeat you’re trying to see along with the noise.
Also, maybe a silly question but: why is there so many components on the board? direct plugging onto the pins of the AD8232 would not work at all?
The AD8232 IC does a lot, but it doesn’t do everything and needs some help from external components. You might be able to eliminate a component or two with careful design, but what’s there is pretty much the minimum needed for the AD8232 IC to function.