EKG-EMG Shield

[Hfleming]

I have just purchased an EKG/EMG shield. After some tinkering I got acceptable results with it. will post more later, but I found a discrepancy between the user manual and and the example sketch.

The documentation indicates that the REF_E jumper should be closed, however, the example sketch leaves the AVR in the internal-reference voltage state, so if an non-technical user uses the shield, there is a chance of damaging the shield, and/or a very noisy signal.

if REF_E jumper is closed, the following line should be added in Setup() :
analogReference(EXTERNAL);

this will switch the reference voltage on the AVR to the reference voltage as supplied by the Olimex shield with the jumper closed.