Read EMG sensor values

[cedricral]

Hi, I need help
I’m using a muscle sensor and have correctly set up all the hardware with the Arduino Uno. However, when I open the serial monitor or the serial plotter, I always get a value around 12 even if I contract the targeted muscle where the electrodes are placed. What could be causing this unexpected behavior?

[jremington]

The code, the sensor or wiring could be a problem.

For informed help, please read and follow the instructions in the "How to get the best out of this forum" post, linked at the head of every forum category.

[gilshultz]

Welcome! If everything is OK and the sensor is connected properly it should work. A wiring error, bad sensor, bad code, grounding, EMI etc will cause problems. I could not see how you wired it so and the software is ok so it is a bad part. I suggest you read the forum guidelines.

[cedricral]

I'm using the next clear code :

int sensorPin = A1;    // select the input pin for the sensor
int sensorValue = 0;

void setup() {
  pinMode(sensorPin, INPUT);
  
  Serial.begin(9600);
}

void loop() {
  // read the value from the sensor:
  sensorValue = analogRead(sensorPin);
  Serial.println(sensorValue);
}

And I'm always gettting the value arround 12

I used the following schematic

[jremington]

Please post a close up, focused picture of your setup. Did you solder connections to the sensor and/or check the continuity of each connection?

If the wiring is correct, the EMG amplifier may be defective.

[cedricral]

I didn't solder the connections to the sensor but only used jumpers to connect them.
I think that continuities are not the problem because when one of the three electrodes is not in contact with the skin, the value of the sensor rises to the maximum.

[jremington]

@cedricral

I didn't solder the connections to the sensor

That is the problem.

[cedricral]

I connected the amplifier to the Arduino with the jumpers cables like in the picture

the EMG amplifier that I used is the next

[jremington]

Are the header pins shown in the product photo soldered to the amplifier board?

Please post a focused, close up photo of your setup, showing the solder side of the PCB.

Use your multimeter to check for +9 and -9V at the board power inputs.

[abdullah_bsee20037]

Hello sir,

We are facing the same issue. I have attached a snapshot of our circuit. Please look into it. Also, the code is written below:

int EMGPin = A0;

int EMGVal = 0;

void setup() {

Serial.begin(9600);

}

void loop() {

EMGVal = analogRead(EMGPin);

Serial.println(EMGVal);

delay(30);

}