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Author Topic: Small Noise Waveform - Electric Guru and Processing App show same  (Read 1062 times)

kstern6

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Attempting to use the EKG-EMG Shield with disappointing results.   I am using this shield with an Arduino UNO, and I have tried several configurations with the same result. 

I've tried using both the blue wrist straps as well as the other type with wire leads and adhesive contacts with gel.

I've used both Electric Guru and the Processing app to visualize the results.  Both apps show the same very small waveform - whether the lead is plugged in or not.  No heartbeat is discernable.  Just a consistent and small waveform.   If I tap either wrist or leg, it does register with a large blip.   It's almost as if the board is not sensitive enough to pick up a heartbeat.  Given that I have tried various hardware configurations and visualization software with the same results, what are the chances that the board itself is faulty?

Thanks!


LubOlimex

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Re: Small Noise Waveform - Electric Guru and Processing App show same
« Reply #1 on: March 20, 2017, 11:21:50 AM »
Did you try adjusting the amplification by manipulating the resistive trimmer? There is a rectangular blue component with a metallic stick in it near the edge of the board. It is named “TR1”. This is resistive trimmer. Rotating the metallic part with a screwdriver changes the resistance of the component and this affects the gain. This is what I recommend – try adjusting the gain by adjusting the trimmer.

>>> Given that I have tried various hardware configurations and visualization software with the same results, what are the chances that the board itself is faulty?

Very close to zero. Each board is tested on a person and calibrated after assembly. It is either a configuration or software issue usually.

Best regards,
Lub/OLIMEX

Technical support and documentation manager at Olimex