Wrong readings from EMG sensor

Daboubet · May 4, 2020, 1:35pm

Hello, I recently acquired a EMG grove sensor. Im using it directly with an Arduino Uno. Im having issues with the readings in the serial monitor.
It just shows values around 300 without making any changes when I move the attached muscles, also shows the same values when the electrodes are not attached. I checked all connections more times and also the code without getting the problem solved.
I’m connecting the yellow cable to the A0 pin, the red one to the 5v and the black to the ground directly into the Arduino board.
Maybe that’s the issue? Do I need to connect the EMG sensor to an external power source instead? I would be really thankful for some help.
Best greetings,
Daniel.

salman · May 5, 2020, 12:27am

Hi @Daboubet, If possible can you share your code and wiring connection here, it help us understand the problem . also try these Grove_EMG_detector_demo_code.ino to read the EMG data from Arduino.

github.com

Seeed-Studio/Grove_EMG_detector_demo_code/blob/master/Grove_EMG_detector_demo_code.ino

// Grove - EMG Sensor demo code
// This demo will need a Grove - Led Bar to show the motion 
// Grove - EMG Sensor connect to A0
// Grove - LED Bar connect to D8, D9
// note: it'll take about serval seconds to detect static analog value
// when you should hold your muscle static. You will see led bar from level 10 turn to 
// level 0, it means static analog value get ok

#include <LED_Bar.h>

LED_Bar bar(9, 8);

int max_analog_dta      = 300;              // max analog data
int min_analog_dta      = 100;              // min analog data
int static_analog_dta   = 0;                // static analog data


// get analog value
int getAnalog(int pin)
{

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Daboubet · May 5, 2020, 3:09pm

Hi @salman, thank you so much for the speedy reply. I atached some pictures and the code to this message. I already tried out the demo code you mentioned, but i’m getting similar results. Have you heard about this issue before? I attached the picture of the actual serial.print reading aswell, now arround 260.
Thank you for your help.

Pics: https://drive.google.com/open?id=1CKJrIOs2RYcadqxZv7CHTegXtoqizjkw

Code:

void setup() {
Serial.begin(115200);
}

void loop() {
Serial.println(analogRead(1));
}

noya · November 9, 2021, 12:44pm

hi, do you solve this problem?

noya · November 9, 2021, 12:52pm

It just shows values around 318 without making any changes when I move the attached muscles, also shows the same values when the electrodes are not attached. I checked all connections more times and also the code without getting the problem solved.

Daboubet · November 9, 2021, 3:16pm

Hi Noya, This was so long ago, I think the issue was related to the power source, try to connect it to an external power supply. maybe can reduce the noise in the signal. Also be aware of the grounding, by connecting everything you have to a common ground. As I remember we never got to read clear values, I just managed to activate a light. The sensor worked more like a switch than a gradual reading of intensity. I hope it helps and good luck!