MyoWare 2.0 Sensor Stuck at Constant Value, No Response to Muscle Movement

Sensors
1

Hello,
I’m using the MyoWare 2.0 sensor to measure hand movements. I’ve purchased 20 sensors and am currently testing them, but they all seem to exhibit similar behavior. When using the sensors for the first time, the values are stuck around the 900s, showing either constant values or consistent noise, and there is no change even with muscle movement.

Additionally, I read in some other posts that adjusting the Gain might solve the issue, so I tried adjusting the Gain as well, but I’m still experiencing the same problem.

Could you offer any advice on what might be causing this issue? Could it be a calibration issue, or is it possibly due to a problem with sensor setup or hardware?
I’ve also tried using an external electrode (Reference Cable), but the problem persists.

Thank you!

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2

Is the usb isolator actually outputting clean power?

Adjusting the gain is the absolute last recommendation in the guides…you will probably have to do some incremental testing to get it set somewhere useful again

https://learn.sparkfun.com/tutorials/1956

3

Thank you for the quick response. I am using this USB isolator:
https://www.amazon.co.uk/Channel-Isolator-Interference-Protection-Isolated/dp/B097Q8FM9L
While testing with the sensor attached, there are moments when the values change to lower values for about 10-20 seconds, during which the sensor responds to hand movements. Could this also indicate an issue with the USB isolator?

4

Can you try running it powered from a laptop or something with a battery instead of the isolator and see how that goes?

5

I have tried all these steps, but the same issue persists.

  • Adjusted the sensor gain as recommended, but no improvement
  • Used external power (like battery) to reduce noise or interference
  • Applied external reference electrode using the MyoWare Reference Cable
  • Tried different muscle groups and adjusted electrode positioning
  • Reset the gain to 50 kOhm, but still the same issue
  • Tried using a USB isolator, but similar issues persist
  • Tested with a battery-powered laptop, but the same issue occurred
6

It might be a defective unit, then - Was it purchased from us? If so head over to Return Policy - SparkFun Electronics (contact vendor if purchased elsewhere) and we’ll get ya squared away

7

I have further troubleshooting details to share. I changed the USB isolator to the Adafruit model (Adafruit USB Isolator - 100mA Isolated Low/Full Speed USB : ID 2107 : Adafruit Industries, Unique & fun DIY electronics and kits), but it still shows the same pattern on the graph as previously shared. Similar to what I mentioned, the sensor will sometimes work as expected for around 20 seconds, showing normal values that respond to finger movements, but it then jumps back to a fixed value of 900 and stays there.

I purchased 20 of these sensors, and I have soldered three of them for testing. Among them, one is also connected to an external electrode (MyoWare 2.0 Reference Cable - CAB-19244 - SparkFun Electronics). I followed the tutorial and disconnected the indicated electrode to use the external reference electrode. However, even with the external electrode, the same issue persists.

Could you let me know if the remaining 17 units, which haven’t been tested, are eligible for a refund? Additionally, since I purchased these sensors from another retailer, could you confirm if they would facilitate the refund through SparkFun?"