No data from SHIELD-EKG-EMG

Started by Janne1002, November 28, 2020, 09:44:17 pm

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Janne1002

I have installed the Olimexino-328 and SHIELD-EKG-EMG by carefully following all instructions in the manual on the Olimex webpages. When I start Electric Guru I get a noisy zero-signal with low amplitude. If I mess with the electrodes I can generate big amplitude noise but once electrodes are stationary, I always get this same zero-signal. I can get some low amplitude oscillations if I only attach one electrode to my arm but once all electrodes are attached the signal is always the same. I can even unplug the electrodes connector to the shield and the signal stays the same. I bought two sets of electrodes and that doesn't change things and I have made Electric Guru installations on a Win10 and a Win7 machines, with no change. Finally, I have switched around the 5-3.3V switch and of course that didn't help. I have posted a trace on my dropbox: https://www.dropbox.com/s/eqrv4iv82a6rrtw/Trace%20typical1%20ElectricGuru.jpg?dl=0
Can somebody please help me get the system going ;D

LubOlimex

What electrodes are you using? How do you place them?
Technical support and documentation manager at Olimex

Janne1002

I'm using the standard shield-ekg-emg-pa. It is light blue and the product number ends with 2359. I bought two sets. It doesn't really matter how I place them, the signal is the same. I have tried to put the L/R below the elbows and on wrists and the D on my ankle and leg and wrist. I have switched them around in various permutations. And of course tried it all with both both bracelets.

Janne1002

Finally I had to order a new SHIELD-EKG-EMG board to confirm my suspicion that my original was somehow damaged. The Olimex-328 was sending data to the serial port, so that's why I suspected the SHIELD. And, yes, as soon as I hooked up the new SHIELD I got good data to elec guru. Now I use Matlab to read the serial port an play with the data. I want to explore the heart coherence topic.

LubOlimex

Glad you manage to find the root of the issue. Interesting how the shield got damaged. Where did you got the original shield from? Was it directly from us?
Technical support and documentation manager at Olimex