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Analog EMG Sensor by OYMotion SKU:SEN0240
(https://www.dfrobot.com/product-1661.html)
Gravity: Analog EMG Sensor by OYMotion
(https://www.dfrobot.com/product-1661.html)
Contents
1 Introduction
2 Specification
3 Board Overview
4 Tutorial
4.1 Requirements
4.2 Connection Diagram
4.3 Sample Code
4.4 Calibration
5 Basic Application
6 FAQ
7 More Documents
Introduction
This EMG sensor is launched by DFRobot and OYMotion cooperation, which can reflect muscle and neural activities of human by detecting sEMG. 
This sensor integrates filtering circuit and amplified circuit. It amplifies minimal sEMG within ±1.5mV 1000 times and depresses noises (especially power frequency
interference) by differential input and analog filter circuit. The output signal is analog，which takes 1.5V as the reference voltage. The output voltage range is 0~3.0V. The
signal strength is depends on muscle activities. The output signal waveform indicates the muscle activity and helps to analyse and research the sEMG. Specifically, we can
use Arduino as a controller to detect muscle activities, e.g. check whether the muscle is tense; the muscle strength;etc. 
This is an active induction sensor can provide high quality signal collection and it is easy to use. Simple preparations are needed to apply the module to whether static or
dynamic areas. Dry electrode is applied to the module and good quality signal are available even without conductive gel. Compared with disposable conductive gel needed by
medical electrodes, it is more convenient to use and has longer service life. Therefore, it is more suited to common users. 
Measurements with an analog EMG sensor are noninvasive, convenient and this can be applied to human-computer interactions. With the development of microcontrollers and
integrated electric circuits, EMG circuits and sensors have not just been applied to traditional medical muscle detection researches but control systems. 
The supply voltage range is 3.3~5.5V; The supply current should not be less than 20mA; The ripple current and disturbance
current should be as low as possible. Stabilized DC voltage is recommended. 
The effective spectrum range is 20Hz～500Hz, and the ADC converter which has higher than 8-bit resolution and 1 KHz
frequency are recommended to take samples and digitized to keep original information. 
Placing the metal dry electrode should consistent with the direction of muscle. 
The product is not a professional medical device and cannot diagnose and cure disease as an assistant device. 
Specification
Signal Transmitter Board
Supply Voltage: +3.3V～5.5V
Operating Voltage: +3.0V
Detection Range: +/-1.5mV
Electrode Connector: PJ-342
Module Connector: PH2.0-3P
Output Voltage: 0～3.0V
Operating Temperature: 0～50℃
Size: 22mm*35mm (0.87inch*1.38inch)
Dry Electrode Board
Electrode Connector: PJ-342
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Summary of content (10 pages)

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Analog EMG Sensor by OYMotion SKU:SEN0240 (https://www.dfrobot.com/product-1661.html) Gravity: Analog EMG Sensor by OYMotion (https://www.dfrobot.com/product-1661.html) Contents 1 2 3 4 Introduction Specification Board Overview Tutorial 4.1 Requirements 4.2 Connection Diagram 4.3 Sample Code 4.4 Calibration 5 Basic Application 6 FAQ 7 More Documents Introduction This EMG sensor is launched by DFRobot and OYMotion cooperation, which can reflect muscle and neural activities of human by detecting sEMG.
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Wire Length: 50cm(19.69inch) Plate Size: 22 * 35 mm(0.87inch*1.38inch ) weight: 36g Board Overview Num Label Description 1 A Analog Signal Output(0~3.0V) 2 + Power Supply Anode(3.3~5.5V) 3 - Power Supply Cathode(0V) 4 PJ-342 Probe Wiring Connector (/wiki/index.php/File:Emg_board_function2.png) Analog EMG Sensor by OYMotion Tutorial The tutorial will show you how to use the analog EMG sensor by printing electromyogram waveform with Serial Plotter of Arduino IDE.
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Sample Code This sample code needs EMGFilters library file, please download and install the EMGFilters Library (https://codeload.github.com/yuyouliang/EMG_Filter/zip/master) file. How to install Libraries in Arduino IDE (https://www.arduino.cc/en/Guide/Libraries#.
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/* * Copyright 2017, OYMotion Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2.
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// the time cost should be measured each loop /*------------start here-------------------*/ timeStamp = micros(); int Value = analogRead(SensorInputPin); // filter processing int DataAfterFilter = myFilter.update(Value); int envlope = sq(DataAfterFilter); // any value under threshold will be set to zero envlope = (envlope > Threshold) ? envlope : 0; timeStamp = micros() - timeStamp; if (TIMING_DEBUG) { // Serial.print("Read Data: "); Serial.println(Value); // Serial.print("Filtered Data: ");Serial.
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5. Open the serial plotter of arduino IDE and the myoelectricity waveform could be seen. In general, the waveform is a line of 0 when the muscle is relaxed, shown as below. It is normal along with occasional peak waveform. (/wiki/index.php/File:%E8%82%8C%E7%94%B5%E4%BF%A1%E5%8F%B7_%E6%94%BE%E6%9D%BE.png) Obviously myoelectricity waveform could been seen in the process of making a fist, shown as below. (/wiki/index.php/File:%E8%82%8C%E7%94%B5%E4%BF%A1%E5%8F%B7_%E6%8F%A1%E6%8B%B3.
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/* Copyright 2017, OYMotion Inc. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2.
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if get EMG singal,number++ and print */ if (threshold > 0) { if (getEMGCount(envelope)) { EMG_num++; Serial.print("EMG_num: "); Serial.println(EMG_num); } } else { Serial.
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(/wiki/index.php/File:%E6%8F%A1%E6%8B%B3%E9%98%80%E5%80%BC.png) 4. Modify the variable threshold to the recorded maximum value. Recommend to modify it to the maximum +100 to improve anti-interference. Reload the sample code to the Arduino control board. 5. Open the serial monitor of Arduino IDE, make a fist and loose it for once then you can see the printed value. Making a fist gently will not count and making a fist with more power will not increase the count value.
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(/wiki/index.php/File:20170615185657.jpg) For any questions, advice or cool ideas to share, please visit the DFRobot Forum (http://www.dfrobot.com/forum/). More Documents EMGFilters Library (https://codeload.github.com/yuyouliang/EMG_Filter/zip/master) New OYMotion EMGFilters Library(github) (https://github.com/oymotion/EMGFilters) Application Post: Application of the EMG Sensor (http://www.oymotion.com/forum.