EMG Sensor - problem.

Hi, greetings from Poland.

I have some questions for you, as more experienced - I am running out of ideas :slight_smile:

Firstly, I have an Arduino uno R3 board and MyoWare muscle sensor (a new release, with integrated electrodes connectors etc.). I want to control a set of servos with EMG signal.

The main power supply is 9V alkaline battery connected with "jack-input" to the board. When I set a totally random value of signal (I mean the entry-level for servo to be closed, eg. 250) it works. It can move as I close/oper my hand. With some problems (I think it can be caused by 9V battery - next time I'll power it with 9V accumulator/battery pack).

But the problem occurs when I want to measure the signal using serial monitor. No matter if the connection is made with USB-cable or USB-cable and the 9V battery, my EMG sensor shows values between 600-630 (and the red LED . The placement of electrodes, pin-connection etc. is the same as previously. The only difference is a connection between my notebook and Arduino (USB-cable).

Any ideas of such malfunction? USB cable is faulty?

Thanks
Andrzej

Are you using a USB isolator?

Also, is your notebook's power cord plugged in? If so, try unplugging it and if it helps.

Thanks.

No, I don't use any isolator. I tried another USB-cable - the problem still exists.

Next step will be, according to what you've said - unplugging my laptop while testing.

Andrzej.