HELP! EMG/Muscle sensor (v3)

I am currently trying to get my muscle sensor v3 with three electrodes to give me readings, and cannot. I’ve scoured through forums and looked over my code and wiring for ages, anybody spot anything?

The batteries are hooked up such that the positive end of Battery 1 is in +Vs, the negative end of Battery 2 is in -Vs, and the remaining free-ends are hooked-up together and connected to the GND. SIG connected to A0 (on Arduino) and GND to GND (on Arduino). (Included since this is hard to see in the attached image).

Two sets of code I found give me different results.

(1) From Sparkfun

AnalogVisualizationArduino.ino : Just gives me a value of 250 +/- 30 on the serial monitor. Flexion doesn’t cause these values to fluctuate, nor does removing the electrodes.

(2) Simply reading from A0
Muscle_Raw.ino: Gives me values of 5 +/- 10 on the serial monitor. Flexion doesn’t cause these values to fluctuate, HOWEVER, removing the electrodes (green in particular) causes the value on the serial monitor to shoot up to 1023.

As such, I have reason to believe that the (newly purchased) kit is not faulty, and perhaps it’s something in my code or a missing factor in wiring which doesn’t allow changes in the Raw_Data during flexion.

Datasheet:

electrodehookup.JPG

AnalogVisualizationArduino.ino (734 Bytes)

Muscle_Raw.ino (491 Bytes)

Hi,

If you purchased the sensor in the last year then unfortunately it is a Chinese counterfeit version of our Muscle Sensor v3 (which Sparkfun used to sell). We stopped making the v3 last year when we released our MyoWare sensor. I highly recommend upgrading to the MyoWare because it can be powered from an arduino directly and has built-in protection against getting burnt out from improper power connections.

If you post some pictures of your setup, I can take a look and see if I spot any issues with your wiring.

Have you tried using the arduino example code for reading analog voltages? It's the easiest code to use when getting started with this sensor.

Cheers,
Brian
Founder - Advancer Technologies

Just noticed your graphic of where you're placing the electrodes. The yellow electrode should be closer to the red electrode. Try placing it an inch away from the red one along the centerline of your bicep.

Made the necessary changes and tried the code you recommended.

Odd turn of events - I'm getting a string of zero's (for all sets of code apart from AnalogVisualiation).

Might this give a hint as to the problem?

Zeros likely point to either the batteries being dead or the software is reading the wrong pin.

Hi, I have the same problem. you solved it?