DIY Muscle Sensor / EMG Circuit for a Microcontroller

Picture of DIY Muscle Sensor / EMG Circuit for a Microcontroller
Measuring muscle activation via electric potential, referred to as electromyography (EMG) , has traditionally been used for medical research and diagnosis of neuromuscular disorders. However, with the advent of ever shrinking yet more powerful microcontrollers and integrated circuits, EMG circuits and sensors have found their way into prosthetics, robotics and other control systems. Yet, EMG systems remain expensive and mostly outside the grasp of modern hobbyist.

This instructable will teach you how to make your own muscle sensor / EMG circuit to incorporate into your next project. Use it to control video games, robot arms, exoskeletons, etc.

Click on the video below for a demonstrations on how to hook up and use your EMG circuit board!

You can now also purchase  EMG sensors, kits, cables and electrodes at!
Muscle Sensor Kit (now also on SparkFun)
Muscle Sensor Electrodes

Note: This sensor is not intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation treatment, or prevention of disease, in a man or other animals.

About Advancer Technologies 
Advancer Technologies is a company devoted to developing innovative game-changing biomedical and biomechanical technologies and applied sciences. Additionally, Advancer Technologies promotes all forms of interest and learning into biomedical technologies. To help culture and educate future great minds and concepts in the field, they frequently post informative instructions on some of their technologies. For more information, please visit .

Remove these adsRemove these ads by Signing Up

Step 1: Materials

Picture of Materials
Click on the links to go to where you can buy items/order free samples.

Circuit Chips

3x TL072 IC Chip  - Free Samples
1x INA106 IC Chip  - Free Samples

Cables and Electrodes
1x EMG Cables   (set of 3)... Note: you could optionally connect the alligator clips directly to the electrodes.
3x EMG Electrodes  

2x 9V Battery
2x 9V battery clips  

• 2x 1.0 uF Tant 
• 1x 0.01 uF Ceramic Disc  
• 1x 1.0 uF Ceramic Disc   

• 3x 150 kOhm 1%  
• 2x 1 MOhm 1% 
• 2x 80.6 kOhm 1%  
• 6x 10 kOhm 1%
• 1x 100 kOhm Trimmer 
• 1x 1 kOhm 1%

• 2x 1N4148 Diode  
Jumper wires
• 3x Alligator clip cables

• 1x Oscilloscope
• 1x Multimeter


To start things off, you’ll need both a positive and negative voltage power supply. We will make these using two 9V batteries.

Now, everyone knows what a positive voltage power supply is, (e.g. common battery) but how do you go about making a negative voltage power supply?

Common electrical circuit rule of thumb is when you connect two batteries in series (eg positive terminal of battery 1 connected to the negative terminal of battery 2) then measure the voltage from the negative terminal of battery 1 and the positive terminal of battery 2, the measured voltage is equal to the summation of the voltages of battery 1 and battery 2.

For this circuit we want a +9V and a -9V power supplies. If we connect our two 9V batteries in series, we will get a power supply of +18V. So how do we get the -9V from these two?

It might help to think about what voltage actually means… voltage is an electrical potential difference. The keyword here is difference. Voltages are only meaningful in terms of the reference point (or more commonly referred to as ground). A voltage is the electrical potential between this reference point and the point you are measuring. Do you see the answer yet?

We do indeed get a +18V voltage reading if we use battery 1’s negative terminal as the reference point… but what if we choose the connection between battery 1’s positive terminal and battery 2’s negative terminal? If we use this point as our reference or ground, then battery 2’s positive terminals voltage will be +9V and battery 1’s negative terminal will be -9V!

Using your breadboard, 9V batteries and battery clips, connect the battery clip wires as shown. However, for the time being, disconnect the positive terminal of battery 2 and the negative terminal of battery 1. It is good practice to always disconnect your power while you assemble a circuit. At the end of the assembly we will reconnect these wires to power the circuit on. (You could also add switches to do this)



Next, we will work on the signal acquisition phase of your EMG circuit which we will use to measure your body’s nervous system’s electrical impulses used to activate muscle fibers.

First, get out your INA106 IC chip (chip A) and insert it into your breadboard as illustrated above. The INA106 is a difference amplifier which will measure and amplify (G=110) the very small voltage differences between the two electrodes you place on your muscle.

Next, grab two 1 M ohm resistors, bend them and then plug them in to your breadboard like the two examples shown. One should connect pins 5 and 6 and the other should bridge pin 1 to your ground rail of your board.

Don’t worry about the other pins of the INA106 for now; we’ll come back to those later.

Step 4: SIGNAL CONDITIONING - Amplification

In this phase, we’re going to take those very small signals measured in the SIGNAL ACQUISITION phase and amplify them.

Let’s start first with two series of amplification; the first will be inverting amplifier with a gain of -15. An inverting amplifier does exactly what it sounds like. It amplifies your signal but also inverts it. You can find more info about inverting amplifiers here

We are going to first build an inverting amplifier with a gain of -15. To do this, we’ll need one of the TL072 chips (chip B), one 150 kOhm resistor and a 10 kOhm resistor. 

Place chip B as the picture indicates. Now use a jumper wire and connect pin 6 of chip A two rows past pin 8 of chip A. Grab one of the 10 kOhm resistors and plug one pin into this row as well. Connect the other pin to pin 6 of chip B. Bend a 150 kOhm resistor and connect one pin to chip B’s pin 6 and the other to pin 7. You can calculate the gain by G=-R2/R1 or in this case G=-150 kOhm / 10 kOhm. (See image 1)

Next, we are going to add a capacitor to AC couple the signal. AC coupling is useful in removing DC error offset in a signal. Read more about AC and DC coupling here

Continuing on, we are going to add an active high pass filter to get rid of any DC offset and low frequency noise. To do this you will need two 150 kOhm resistors and a 0.01uF capacitor. Use a jumper wire and the 0.01 uF capacitor to bridge the center gab of your breadboard as shown. (One end of the jumper wire should be connected to pin 7 of chip B). The 150 kOhm resistor will connect the capacitor you just placed to pin 2 of chip B. Now, bend the 150 kOhm resistor and push it into connect pins 1 & 2. (See image 2)

Also, go ahead and connect chip B’s pin 4 to your -9V rail, pin 8 to your +9V rail, and pins 3 & 5 to your GND rail.


Step 5: SIGNAL CONDITIONING - Rectification

Picture of SIGNAL CONDITIONING - Rectification
In this phase, we will be rectifying the signal using an active full-wave rectifier . Our rectifier will take the negative portion of our signal and turn it positive so the entire signal falls within the positive voltage region. We will use this coupled with a low pass filter to turn our AC signal in to a DC voltage; readying the signal to be passed to a microcontroller.

You will need five of the 10 kOhm resistors, both 1N4148 diodes, and a second TL072 chip. Warning… this will be the most difficult phase to assemble! Pay close attention to the pictures!

First, plug in a TL072 chip (chip C) and connect -9V rail to pin 4, the +9V rail to pin 8 and GND to pin 3, as shown in the first image.

Next, place a 10 kOhm resistor (let’s call it resistor A) connecting pin 1 of the TL072 chip from the amplification phase and plug the other end into the row next to the 0.01uF capacitor’s row. Use a jumper wire to connect this row to pin 2 of the second TL072 chip. The next 10 kOhm resistor we’ll call resistor B. Resistor B’s first pin should be plugged into the row where resistor A’s second pin is plugged in and resistor B’s other pin should be plugged into the row two down. Another 10 kOhm resistor’s (resistor C) first pin should be plugged into the row where resistor A’s second pin terminated (same as resistor B) but the other pin should be plugged into the next immediate row over. (See image #2)

Now get out the two 1N4148 diodes. Diodes are polarized so be sure to pay attention what direction you plug them in! We’ll call these diodes A and B. Plug diode A’s positive end (end with black strip) into pin 1 of chip C and plug the negative end into the row of resistor C’s second pin. Get diode B and plug the NEGATIVE end into pin 1 of chip c and plug the POSITIVE end into the row of resistor B’s second pin. (See image #3)

Next, use two jumper wires to bridge the center gap for resistor C and B’s rows. Use another jumper wire to connect the jumper wire’s row connected to resistor B’s row to pin 5 of chip C. Use another 10 kOhm resistor to connect the jumper wire’s row connected to resistor C’s row to pin 6 of chip C. Finally, use the last 10 kOhm resistor to connect chip C’s pins 6 and 7. (See image #4).

Phew… that is for the rectifying phase! Next is the filter phase.

Step 6: SIGNAL CONDITIONING - Smoothing + Amplification

In this last phase of circuit assembly, we will be using an active low-pass filter to filter out the humps of our signal to produce a smooth signal for our microcontroller.

You will need the last TL072 chip (chip D), the two 80.8 kOhm resistors, the 100 kOhm trimmer, the 1 kOhm resistor and the 1.0 uF ceramic disc capacitor.

First, plug in chip D and connect +9V to pin 8, -9V to pin 4, and GND to pins 3 & 5. (image #1).

Now, grab one of the 80.6 kOhm resistors and connect one end to chip C’s pin 7. Connect the other end to chip D’s pin 6. Next grab the other 80.6 kOhm resistor use it to connect chip D’s pin 6 and 7. Do the same thing for the 1.0 uF capacitor. (image #2)

That’s the end of the filter circuit. However, since this is an active filter, there is a side effect of inverting the signal. We will need to invert the signal one more time (and have the ability to amplify it more if desired) using another inverting amplifier circuit with a trimmer configured as a variable resistor.

Use a jumper wire, connected to chip D’s pin 7, and the 1 kOhm resistor to bridge the board’s center gap. Use another jumper wire and connect the 1 kOhm resistor to chip D’s pin 2. Next, place the trimmer one row over with the pins laid out and a jumper wire connecting two of the pins as pictured. Finally, place the last two jumper wires as indicated. (image #3)

By using a screw driver and turning the trimmer, you will be able to adjust the gain of your signal to account for different signal strengths from different muscle groups. Start out with it set pretty low and go up from there (~20 kOhms).

Step 7: Circuit Review

Picture of Circuit Review
(Optional) If you have an oscilloscope and a wave generator handy, now would be a good time to step through the circuit and test each phase.

If you do not have an oscilloscope handy, go back and review your circuit connections step by step to make sure you have place each component correctly. Pay close attention to the power pins and connections of your chips. If you have these incorrect, you could burn out your chips!

Step 8: Electrode Cables

Next, you'll need to make some changes to the EMG electrode cables since I have been unable to find a vendor who sells the cable's style DIN connector's female compliment.  (if any one has a suggestion please let me know!)

Grab a pair of scissors, wire cutters, wire strippers, pocket knife, etc.... basically anything sharp and strip about a 1/4" of the end of the DIN plug on all three cables (the plug end not the snap end).

Next, clip an alligator cable to each of the wires. We will use these to connect the electrode cables to our breadboard with some jumper wire. You could do as I have done and strip the wire and then solder on terminal pins but it is not necessary and the alligator clips will do fine.

Step 9: Surface Electrodes

For the electrode placement, you will need three surface electrodes.

After determining which muscle group you want to target (for example I will be using my right bicep) and cleaning the skin thoroughly, place one electrode on your skin above the middle of the length of the desired muscle. Let's call this the mid muscle electrode.

Next, place a second electrode at one end of the muscle. We'll call this the end muscle electrode.

Last, place the third electrode on a bony part of your body nearby the muscle group. We'll call this the reference electrode. For example, for the biceps, I am placing the reference electrode on the bony end of my forearm close to my elbow.

Using the snap connections of the electrode cables, snap each cable to each electrode. Make a mental note of which color cable is attached to which electrode.

Step 10: Connecting Electrode Cables

Now you are ready to connect your electrode cables to your circuit. Remember those pins on chip A that we put aside till later?

Connect the reference electrode to the GND rail of your circuit.
Connect the mid muscle electrode to chip A's pin 2
Connect the end electrode to chip A's pin 3

Lastly, we need to add some circuit protection via capacitors. Tanthium capacitors are polarized like the diodes we used earlier. These are easier to tell which is the positive pin and negative pin since one is always marked with a + sign indicating positive pin. Connect one 1.0 uF tant. capacitor between the +9V rail and GND rail, with the positive end connected to the +9V rail. Connect the other 1.0 uF capacitor to the -9V and GND rails, with the positive end connected to the GND rail.

Now you'll ready to power on your circuit!

Step 11: Connecting to a Microcontroller

Before connect your circuit to your microcontroller, you should power on your circuit (by connecting the battery wire's we disconnected earlier) and check the output voltage with a multimeter to make sure it is within your microcontroller's analog input pin's tolerances. To do this, connect the negative multimeter probe to your GND rail and connect the positive probe to pin 1 of chip D. Make sure the voltage measured is less than the max voltage of your input pin!

If you've done that check and everything thing looks fine, use jumper wires to connect pin 1 of chip D to an analog input pin of your microcontroller and your GND rail to the GND pin of your microcontroller.

Congratulations you're done!

Step 12: Arduino Demo

Picture of Arduino Demo
For this demo, we used an Arduino Duemilanove microcontroller hooked up to a PC running Processing visualization software. 

Remember to visit us at for kits and fully assembled sensors!

Step 13: EMG Circuit Schematic

Picture of EMG Circuit Schematic
Click the i box in the top left to see a larger version... or go to our website and click on the EMG schematic image .
1-40 of 244Next »
RománV111 days ago

what programs and code for arduino you used for the data acquisition and the visual representation of the emg signals?, thanks for your time and for your project (:

Gundanium (author)  RománV19 days ago
Hi The sample code can be found on our website:

Hello, I am Malaysia
university student that need your help for my final year project. i need
a schematic diagram for muscle sensor/emg signal amplifier. and i want
to ask..can i use apc220 to transmit signal from adruino to laptop?
idea for this project is:

muscle->signal amplifier->adruino->apc220 transmitter-> apc220 reciever->laptop using processing.

i hope you can help me n correct me if i wrong.

thank you;

i couln't find INA106 can u suggest another IC instead of that?

i couln't find INA106 can u suggest another IC instead of that?

hai am bhavana, the project is very good , building our own EMG circuit for many applications, iam thinking to use this in my project, but my question is where can i get the software or program to be installed into arduino. please help in this regard
thank u
Gundanium (author)  chepuri bhavana9 days ago

Gundanium (author)  chepuri bhavana9 days ago

It can be found on our website

Can u help me with connecting arduino to the computer and logging the data? Or share your code with me. My email id is

Suchso24 days ago

Any alternate ic for ina106.

Gundanium (author)  Suchso9 days ago

I don't know of any that can simply swapped out. However, there are other ICs that are suitable for the first stage of the circuit. For instance, AD620 or the AD822* family of ICs (e.g. AD8226, AD8221). Our latest sensor uses the AD8226:

Can i use this sensor more than one time ?

Gundanium (author)  ahmed.yousif.96159 days ago

Yes. Why wouldn't you?

i am using proteus software and i do not have ina106 in my library .plz guide me what should i do. 2nd thing plz send me clear areas and schematic of DIY muscle sensor at

because it is not clear on website

Waiting for a kind response.


hi hello.. i want to use it for my fyp project this month.. can i know more detail about this project.. my email : . and may i now , can i get the signal by using labview software?

kkops2 months ago

can u suggest any reuseable EMG electrodes that will work with this circuit?

Gundanium (author)  kkops1 month ago
The conductive fabric tutorial on our website should work.
oscar2564 months ago

How much is the max amplification for biosignals it has the circuit? Reading a little, i see: G=110 for the INA106. G= -15 for the first opamp, G= -1 for the second opamp, and G=POT/1K for the last opamp. So the final gain is G=(1650)(POT/1K)??? is this correct?? And the max gain is G=165000????

Gundanium (author)  oscar2561 month ago
Right. The max gain isnt usually required
J_Aparecido5 months ago


I managed to assemble this project is operating normally ... like a hint, how can I increase the sensitivity of the circuit? For example, if I want to monitor variations in electrical potential without even having muscle contractions, or in a state of relaxation or strees would be an example.

I tried to increase or decrease the gain resistor between pins 5 and 6, but to no avail, however lost sensitivity.

I'm starting in the area of electronics, if someone give some hint where I can find information on, I thank you.

And sorry, my english is not very good, I am "writing" with the help of a translator ...

Thank you,

Gundanium (author)  J_Aparecido1 month ago
Youd probably be best using the raw emg waveform rather than the envelope. Just use an instrumentation amplifier like the first stage of this circuit. Remove DC offset from its ouput with a high pass filter and then amplifier with as much gain as you need to get the sensitivity youre looking for.
AtlasGe9 months ago

dear Gundanium(it seems you are a gundam lover hummm?) i need your help!

i thought i've correctly drawn the .sch file(or at least made it looks like a right one)

also i've tried to turn it into a pcb design

but as i pressed the button 'PCB Quote', there is something wrong and I have nothing to do about it.

what is the signal layer and how to 'put' copper on it?

is it the right way i'm taking?

any kind help is apprecited!


Gundanium (author)  AtlasGe1 month ago
Id suggest contacting the software maker to help you troubleshoot your issues with their program
KalRob8 months ago

This is great, does anyone have the PDF file of this? I can't download it. Also, what areas would you change/ replace to make this better? Thank you!

Gundanium (author)  KalRob1 month ago
Our Muscle Sensor v3 uses an improved circuit. The schematic is on our website.
dhivya136 months ago

Hi can i ask if this circuit can be used with Matlab software to display results?

Gundanium (author)  dhivya131 month ago
Yes but youll need a DAQ or some other ADC such as a microcontroller.
rudiclan5 months ago

Hello, I have a problem with the circuit. Sometimes everything works fine and sometimes there is no signal. I used a scope to measure each step an figured out that I have a high DC offset after the first ampification step (AD620 with gain of arround 110). The DC offset is about 800 to 1500mV but I see a oscillation when I use the muscle. Now the signal gets amplified by a factor of 15 and the opamp saturates (constant 8,x V). After the ac couple with the capacitor the signal gets zero. Is it possible to reduce the DC offset or decouple the signal before the second amplification step? Thank you!

Gundanium (author)  rudiclan1 month ago
Check out the schematic for our latest muscle sensor. We improved the circuit to eliminate this problem. However, the still is the potential for DC offset because of the instrumentation amplifier input bias current which can polarize the electrodes. Our next generation sensor addresses this problem. Should be out next year.
thorshammer4 months ago

Hi, I was wondering if it was possible for me to replace the tantalum capacitors with ceramic ones

Gundanium (author)  thorshammer1 month ago
Should be fine
oscar2564 months ago

What is voltage it receives the human body due to the electrodes and
amplifier circuit? Also is it safe to apply to people with pacemakers or

Gundanium (author)  oscar2561 month ago
There isnt built in patient isolation. Always use a battery to power the circuit to isolate the circuit from the power grid.

receiving a greeting hello, I'm working on a prosthetic leg, and I wonder if I can use their entire system for sensors and servos and if so to import the produto, thank you very much

We dont ship internationally for oders taken through our webstore. Some of our distributors do however. I would recommend ordering through one of then.
jrosales59 months ago
How do you know in what part of the body put the three electrodes? For example how i put the electrodes for sense the fingers or my leg or other part of my body?
Gundanium (author)  jrosales51 month ago
You have to first find the muscle body. Then put one electrode in the middle of the muscle and the second a short distance away. And the third on a electrically inactive part of the body such as the bony part of the forarm. You can use an anatomy book to figure out less obvious muscles.

To enable the emg to detect the current that produce by the contraction
of muscle, basically u need at least 3 electrode which is, two of the
electrode must be positioned near to the skeletal muscle, and the other
electrode must be placed in neutral area. Neutral area means that no
muscle tissue on it. The last electrode was used to cancel the noise
that produced.

Gundanium (author)  jrosales59 months ago

That takes some knowledge in Anatomy. It'd consult with anatomical diagrams to figure out where the muscle you want to measure is located. Also, not every body is the same so it might take some trial and error to figure out the best location for the electrodes.

vinay07451 month ago

Does these electordes are used for once.....or can be used for ''n'' times...

1-40 of 244Next »