Introduction: Backyard Brains: a Size Down

Hello, Makers and Viewers alike!!!!!!!!!!

Lately, I've been dabbling in biomedical technology. This company named Backyard Brains (check them out in the below link) has made a device that can actually quantify the amount of voltage your muscles are making when you flex.

This is called a myograph. See the video that I prepared that demonstrates how this strange and wonderful device works:

Today, I will be explaining the underlying details of how one would go about using this device. To find out about the company that makes these chips go here:


Step 1: The Spiker Box

When you are looking to perform the kinds of experiments seen in the video, you are going to need to purchase a Spiker Box. This is the device that will be reading your flexing signals. Attached to it are three electrodes. These are what you saw me attach to the muscle of choice.

As mentioned in the video, one of these three electrodes will act as our ground pin, being placed where little muscle stimulation is occurring. In an experiment, this is our control.

The remaining two red electrodes will be placed along our muscle of choice from which the data will be collected.

Step 2: My Arduino of Choice

As you may notice, this is NOT the arduino uno. This, is the Uno's smaller twin brother, better known by Adafruit as the Metro Mini made by Limor Fried of Adafruit.

You can buy this at:

The Metro Mini runs on Arduino code and requires no additional IDE installations. It has the same amount of data storage (2 kilobytes) and has many potential realms of implications.

The advantage that this arduino has over other types is its size. Since it takes up little room, this leaves us room for shrinking down our projects to make them more portable.

That is the purpose of this lesson. I will be teaching you how to use this arduino and hook it up with a visual display and the Spiker Box so that you have a fully functional myograph.

Step 3: Our Visual Display

One thing that I took into account is that when measuring how much electricity you can generate from your muscles is NO ONE WANTS TO HAVE TO USE A COMPUTER TO DO IT!

So....I am using a display that we can attach to our arduino so that way our project is not connected to a computer and we can still see the incoming data.

Lets get a quick dissection of this device.

As you can see on the diagram, the oled has a ground and power (5v). This is nothing new. might be noticing there are 2 new pins on the Oled that you are not familiar with. That is 2000% okay.

Meet Clock(Green) and Data(Yellow). You do not have to understand how they work now. For a general picture, all these pins do is reduce the amount of wires you need to communicate between the Oled and arduino. It is these two pins that will be sending and displaying the data of your muscles without a physical computer.

Step 4: Components to Your Circuit

Now when you begin to work on constructing your circuit, make sure you have the following things:

-1 Metro mini 5V

-1 Oled (see here to buy on Amazon:

-1 Spiker Box set (Buy set here at: Which within it you need:

-3 Electrodes to be placed on your body (2 red, 1 black) attached to an orange cable (Not shown Above)

-The actual shield (this fits with an Arduino Uno, but we're using the Metro Mini)

Of course, when setting up to make your connections, make sure you have enough wires to do so.

Step 5: Connect Your Powers and Grounds

It is as easy as it sounds. Using your 5V and ground pins on your metro mini arduino, connect them to your two main devices.

When attaching your power terminals to your myograph shield, it is helpful to place it against an arduino uno for refference. However, if you look on the side of the shield with green LED, you should see small labels where 5V and ground are. Use the Image above to see how you connect your powers to your shield.

Your oled (the display) should have its 5V (VCC) pin and ground pins labeled. Connect them appropriately.

Step 6: Connect Your INPUTS

When connecting your input Pin to your myograph, use an arduino UNO as a refference.

Attach the pin on your shield where A0 would be on an UNO to any one of the analog Pins on your Metro Mini. In this case, I attached the A0 on the shield to A0 on the Metro Mini.

Now here is the tricky set of connections. When hooking up your inputs to your Oled, you are going to have to remember this:

The Metro Mini has a built in Data and Clock in Pins A4 and A5, respectively. Better Shown as:

A4------------->SDA (data), Marked In Yellow above

A5------------->SCL(Clock), Marked in Dark Green above

Your Clock and Data pins should be marked on your Oled and A4 and A5 are labeled on your Metro Mini.

Once you finished these connections...CONGRATULATIONS!!! You finished a complete circuit which can now measure the direct output of your flexing Muscles!

Step 7: Setting Up Your Experiment

Now you are ready to begin setting up for your experiments.

There are 3 things you want to do in preparation to your experiment.

1) Your electrodes that you will put on your body are attached to an orange cord. This cord should be inserted into an orange port on the Myograph shield.

2) Take your ground electrode (black) and place it on a part of your body that you will NOT be flexing. This will act as a reference to compare to your results.

3)Place your 2 remaining red electrodes and place them along the muscle you are trying to measure.

After doing these 3 things and if your arduino is up and running, then you're READY TO START FLEXIN'!!!!!

Step 8: Get the Code!!!!!

The original code can again be found on Backyard Brains.

But...Since I appreciate your support so much, I have posted my variant of it (with the oled display) on my Github account under Gears N' Genes. Here is a direct link to get the code:

Please tell me if you managed to perform this experiment and tell me what modifications and additions you've made in the Comments Below!!!

On a Final Note...

I hope you enjoyed that lesson! Again, this is the first time I gave this type of lesson. But please, tell me what you think of this shield. I believe that it would increase the potential number of projects substantially if the shield was smaller. With something as powerful as Backyard Brain's Myograph the size of a Metro mini, huge medical breakthroughs could be achieved.

And the Best part is...the people who achieve those breakthroughs don't have to be doctors! They can be you!