EMG-Shield with Arduino-DUE (Noise Problem)

[mbkmbg]

Hello

I'm using Arduino_DUE with 4-EMG_Sheilds.

Setup:
  1- operating voltage = 3.3v
  2- REF-E enabled on first shield and disabled on other shlields
  3- 12-bit resolution (==> max_value= 4096)
  4- frequency = 200 Hz
 
without connecting the electrodes, i received a signal with low noise but with mean value of 1600

after connecting the electrodes i received a very noisy signals


my question is, what is the shape of signal should i expect?
and the range 0 to 4096 does it mean (0 to 3.3v)or (-3.3v to 3.3v)?

thanks

[LubOlimex]

Did you place the electrodes on the location you want to measure? If you leave the electrodes unattached to anything there can be noise.

It is 0 to 3.3V range.