Introducing Circuit Playground

By Adafruit Industries

Courtesy of Adafruit

Guide by Lady Ada


Would you like to learn electronics, with an all-in-one board that has sensors and LEDs built in? Circuit Playground is here, and it's the best way to practice programming on real hardware. No soldering or sewing required!

Circuit Playground features an ATmega32u4 micro-processor, just like our popular Flora. It also is round and has alligator-clip pads around it. You can power it from USB, a AAA battery pack, or Lipoly (for advanced users). Program your code into it, then take it on the go.

  • ATmega32u4 Processor, running at 3.3V and 8MHz
  • MicroUSB port for programming and debugging with Arduino IDE
  • USB port can act like serial port, keyboard, mouse, joystick or MIDI

Introducing Circuit Playground

Circuit Playground has built-in USB support. Built in USB means you plug it in to program it, it just shows up - all you need is a Micro-B USB cable, no additional purchases are needed! With the new 1.6.4 Arduino IDE, it takes only a few seconds to add support. The Circuit Playground has USB HID support, so it can act like a mouse or keyboard to attach directly to computers.

Here's some of the great goodies baked in:

  • 10 x mini NeoPixels, each one can display any rainbow color
  • 1 x Motion sensor (LIS3DH triple-axis accelerometer with tap detection, free-fall detection)
  • 1 x Temperature sensor (thermistor)
  • 1 x Light sensor (phototransistor)
  • 1 x Sound sensor (MEMS microphone)
  • 1 x Mini speaker (magnetic buzzer)
  • 2 x Push buttons, left and right
  • 1 x Slide switch
  • 8 x alligator-clip friendly input/output pins Includes I2C, UART, and 4 pins that can do analog inputs/PWM output
  • All 8 pads can act as capacitive touch inputs
  • Green "ON" LED so you know its powered
  • Red "#13" LED for basic blinking
  • Reset button

We've started out with a Developer Edition of Circuit Playground. This version is designed for people who have a little experience with Arduino already, who want to help build & document projects. There might be minor hardware or software bugs. Once we feel like the design is really solid we'll revise/re-release it into a universal edition for anyone to use!

Introducing Circuit Playground


Introducing Circuit Playground

Circuit Playground is chock-full of blinkies, sensors and electronic goodies. Since there's a lot going on, we're going to look at each piece one by one and talk about what it is and how to use it. This is a technically-oriented description for the Developer Edition and the people who are planning on writing code for Circuit Playground.

GPIO Capacitive Touch Pads

Introducing Circuit Playground

All 8 non-power pads around the circuit playground have the ability to act as capacitive touch pads. Each pad has a 1Mohm resistor between it and digital pin #30. You can toggle this pin to control whether the resistor is a pullup or pulldown or floating. Note that this means that all the pads have a 2Mohm resistance between them.

You can also of course just use those pads for GPIO, we expose the hardware Serial (TX RX), hardware I2C (SDA SCL) and 4 gpio pins that can also do analog readings. They are the same exact pins as those on the Flora.


Introducing Circuit Playground

Each Circuit Playground comes with 10 'NeoPixels' (technically, SK6812-3535 chips). These are connected to digital pin #17 and are powered by the 3.3V regulator. This is technically undervolting but we test them at this voltage and they work fine, if slightly tinted.


Introducing Circuit Playground

There are three tactile pushbutton switches. One is the Reset button. Press this button once to reset, double-click to enter the bootloader manually.

The other two buttons are the Left and Right buttons, connected to digital #4 (Left) and #19 (Right) each. These have pull-down resistors installed so are, by default, LOW and when pressed read HIGH. This is to make if-then logic a little easier to read for beginners.

Slide Switch

Introducing Circuit Playground

There is a single slide switch near the center of the Circuit Playground. It is connected to digital #21 and will read LOW when slid to the left, and HIGH when in the right hand position.

Light Sensor

Introducing Circuit Playground

There is an analog light sensor, part number ALS-PT19, in the top left part of the board. This can be used to detect ambient light, with similar spectral response to the human eye.

This sensor is connect to analog pin #A5 and will read between 0 and 1023 with higher values corresponding to higher light levels. A reading of about 300 is common for most indoor light levels.

Temperature Sensor 

Introducing Circuit Playground

There is an NTC thermistor (Murata NCP15XH103F03RC) that we use for temperature sensing. While it isn't an all-in-one temperature sensor, with linear output, it's easy to calculate the temperature based on the analog voltage on analog pin #A0. There's a 10K resistor connected to it as a pull down.

Speaker Buzzer

Introducing Circuit Playground

You can make your circuit playground sing with the built in buzzer. This is a miniature magnetic speaker connected to digital pin #5 with a transistor driver. You can use PWM at varying frequencies to make basic tones.

Microphone Audio Sensor

Introducing Circuit Playground 

A MEMS microphone can be used to detect audio levels and even perform basic FFT functions. You can read the analog voltage corresponding to the audio on analog pin #A4. Note that this is the raw analog audio waveform! When it's silent there will be a reading of ~330 and when loud the audio will read between 0 and 800 or so. Averaging and smoothing must be done to convert this to sound-pressure-level.

Triple-Axis Accelerometer 

Introducing Circuit Playground

A LIS3DH 3-axis XYZ accelerometer is in the dead center of the board and you can use it to detect tilt, gravity, motion, as well as 'tap' and 'double tap' strikes on the board. The LIS3DH is connected to the hardware SPI pins (to leave the I2C pins free) and has the CS pin on digital pin #8 and an optional interrupt output on digital pin #7 (also known as IRQ #4).

Windows Driver Installation

Introducing Circuit Playground

Before you plug in your board, you'll need to possibly install a driver!

Click below to download our Driver Installer.

Download Adafruit Windows Driver Installer

Download and run the installer.

Introducing Circuit Playground

Run the installer! Since we bundle the SiLabs and FTDI drivers as well, you'll need to click through the license.

Introducing Circuit Playground

Select which drivers you want to install, we suggest selecting all of them so you don't have to do this again!

Introducing Circuit Playground

By default, we install the Feather 32u4 , Feather M0, Flora and Trinket / Pro Trinket / Gemma / USBtinyISP drivers.

You can also, optionally, install the Arduino Gemma (different than the Adafruit Gemma!), Huzzah and Metro drivers.

Click Install to do the installin'.

Introducing Circuit Playground

Arduino 1.6.x IDE

The Arduino IDE version 1.6.x is the latest version of Arduino and recommended for most users.  Follow the steps on this page to learn how to install a version of the Arduino 1.6.x IDE with support for Adafruit's boards.

Super Easy Installation (Recommended)

With the Arduino IDE version 1.6.4 and greater you can now add 3rd party boards directly from the stock IDE!  The first thing you will need to do is to download the latest release of the Arduino IDE. You will need to be using version 1.6.4 or higher:

Latest Arduino IDE Download

After you have downloaded and installed the latest version (remember it must be 1.6.4 or higher), you will need to start the IDE and navigate to the Preferences menu. You can access it from the File menu in Windows or Linux, or the Arduino menu on OS X.

Introducing Circuit Playground

A dialog will pop up just like the one shown below.

Introducing Circuit Playground

We will be adding a URL to the new Additional Boards Manager URLs option. The list of URLs is comma separated, and you will only have to add each URL once. New Adafruit boards and updates to existing boards will automatically be picked up by the Board Manager each time it is opened. The URLs point to index files that the Board Manager uses to build the list of available & installed boards.

To find the most up to date list of URLs you can add, you can visit the list of third party board URLs on the Arduino IDE wiki. We will only need to add one URL to the IDE in this example, but you can add multiple URLS by separating them with commas. Copy and paste the link below into the Additional Boards Manager URLs option in the Arduino IDE preferences.

Introducing Circuit Playground

Add the Adafruit Board Support package!


Copy Code

Into the "Additional Board Managers URLS" box

Introducing Circuit Playground

Click OK to save the new preference settings. Next we will look at installing boards with the Board Manager.

Manage Board Support

Adding the link to the Adafruit board support package does not actually install anything, it only tells the Arduino IDE where to find the software.

Now that you have added the appropriate URLs to the Arduino IDE preferences, you can open the Boards Manager by navigating to the Tools->Board menu.

Introducing Circuit Playground

Once the Board Manager opens, click on the category drop down menu on the top left hand side of the window and select Contributed. You will then be able to select and install the boards supplied by the URLs added to the preferences. In the example below, we are installing support for Adafruit AVR Boards, but the same applies to all boards installed with the Board Manager.

Introducing Circuit Playground

Next, quit and reopen the Arduino IDE to ensure that all of the boards are properly installed. You should now be able to see the new boards listed in the Tools->Board menu.

Finally follow the steps below for your platform to finish the installation - basically installing drivers and permissions management.

Also check out the troubleshooting section for some advice on common errors.  Have fun using Adafruit's boards!

All-in-one Installation (not recommended!)

If you have trouble using the super easy installation method above another way to install support for Adafruit's boards is with the following preconfigured Arduino IDE downloads.  It isn't recommended because you won't have the latest IDE!

Just grab the right file for your platform and use it like the normal Arduino IDE.  Adafruit's boards like Trinket, Pro Trinket, Gemma, and Flora are configured to show up in the board list automatically.

Arduino 1.6.4 with Adafruit Boards for Windows

Arduino 1.6.4 with Adafruit Boards for Mac OSX (10.7 )

Arduino 1.6.4 with Adafruit Boards for Linux (32-bit)

Arduino 1.6.4 with Adafruit Bards for Linux (64-bit)

Once you've downloaded and installed the IDE follow the steps below for your platform to finish the installation:

Also check out the troubleshooting section for some advice on common errors.  Have fun using Adafruit's boards!

Manual Installation (super advanced!)

If you have your own version of the Arduino IDE or would like to install the Adafruit boards yourself then follow the steps below.  However it is highly recommended that most users stick to the easy install downloads above!

With the 1.6.x version of the Arduino IDE the process of adding support for new boards is much simpler than previous versions.  First start by downloading a version of the Arduino 1.6.x IDE and installing it as normal.  Note that these instructions are only tested to work against the Arduino 1.6.4 IDE, earlier or later versions may or may not work!

Once you've installed the stock Arduino IDE download and unzip the following file which contains Adafruit's board definitions:

Adafruit Board Definitions

Unzip the file and navigate inside the Adafruit_Arduino_Boards folder to find a hardware subfolder with a small hierarchy of files, and a drivers folder with Flora drivers specific to Windows.

Next find your installed Arduino IDE's hardware subfolder.  For Windows and Linux the hardware subfolder should be directly beneath the folder where Arduino's IDE was installed.

For Mac OSX the folder is hidden inside the application bundle.  Right click on the Arduino application and click 'Show Package Contents', then navigate to the Content -> Resources -> Java folder to find the hardware subfolder.

Once you've found Arduino's hardware subfolder carefully merge in the contents of the hardware folder from Adafruit's board definitions, being sure to overwrite any file that conflicts (only avrdude.conf should conflict).  When you're done the Arduino hardware folder should have the following hierarchy:

  • hardware
    • adafruit
      • avr
        • The contents of the hardware/adafruit/avr folder from Adafruit's board definitions.  There will be a boards.txt, platform.txt and variants subfolder.
    • arduino
      • No changes to this hierarchy, it is exactly as provided by the Arduino IDE.
    • tools
      • avr
        • etc
          • avrdude.conf - This version of avrdude.conf should be from Adafruit's board definitions and completely overwrites the version provided by the Arduino IDE.
        • ... all other files as provided by the Arduino IDE.
      • ... all other files as provided by the Arduino IDE.

Finally on Windows only, copy the contents of the drivers folder from the board definitions download into the Arduino IDE's drivers folder (it's a sibling of the hardware folder you found earlier).

That's all you need to do to manually install Adafruit's boards with the 1.6.x version of Arduino!  Now follow the steps below for your platform to finish the installation:

Also check out the troubleshooting section for some advice on common errors.  Have fun using Adafruit's boards!


I just plugged it in and I can't seem to connect to my Circuit Playground with Arduino!

99% of initial problems with circuit playground are due to having charge USB cables instead of sync cables. Do  not use a cable you've only used for charging a phone. Make sure its a cable that can pass data as well as power. Lately, there's been a lot of products shipped with charging only cables and it's very confusing because the Circuit Playground lights up but does not show up in the Arduino IDE!

So, please, try multiple USB cables, and if you find a charge-only cable, cut it in half and throw it away so you will not make the mistake again!


We wrapped up everything you need to run Arduino code on your Circuit Playground is wrapped up into a tidy library that integrates all the sensing and lighting.

Installing Via Library Manager

The Circuit Playground library is available on the Adafruit GitHub website.  The library is installed in versions of the Arduino IDE greater than 1.6.7 as follows:

  • In the menu click "Sketch", then "Include Library"
  • At the top, click "Manage Libraries. . ."
  • Type "Circuit Playground" in the search box.  You should see Adafruit Circuit Playground listed.

Download Adafruit_CircuitPlayground 'Manually'

To begin working with Circuit Playground, you will need to download Adafruit_CircuitPlayground from our github repository. You can do that by visiting the github repo and manually downloading or, easier, just click this button to download the zip.

Download Adafruit CircuitPlayground Library

Rename the uncompressed folder Adafruit_CircuitPlayground and check that the Adafruit_CircuitPlayground folder contains Adafruit_CircuitPlayground.cpp and Adafruit_CircuitPlayground.h

Place the Adafruit_CircuitPlayground folder your arduinosketchfolder/libraries/ folder. You may need to create the libraries subfolder if it's your first library. Restart the IDE.

We also have a great tutorial on Arduino library installation at:

Run the Demo

Plug in your Circuit Playground. Under Windows you'll need to make sure you have installed the driver package. Do that if you haven't!

Next, you'll also need to make sure you have installed the Adafruit Board Support package. That's required no matter what computer you're using.

Select the Circuit Playground Board

Under the Tools -> Board submenu, scroll down to Adafruit Boards and pick Adafruit Circuit Playground

Introducing Circuit Playground

Select the matching Port

Under Tools->Port select the port that is labeled (Circuit Playground)

Introducing Circuit Playground

Load the Demo Program

OK you're now ready to load the demo. Under File->Examples locate Adafruit CircuitPlayground and then select the demo program.

Introducing Circuit Playground

Compile/Verify the Demo

Click the Verify button (also the Sketch->Verify menu item) to compile/verify the demo. Make sure you get "Done compiling." and no errors

Introducing Circuit Playground

Upload Demo

Click the Upload button to upload the code

Introducing Circuit Playground

You should get a Done uploading. message in the blue statusbar

Introducing Circuit Playground

You can now run the serial console to get data output:

Introducing Circuit Playground

You'll get information such as:

  • "Capacitive touch" readings for all 8 outer pads (under 50 means not touched, over 100 usually means the pads are touched)
  • Slide switch location (left or right)
  • If the Right and Left buttons are pressed
  • Light sensor readings, higher values mean more light
  • Sound sensor readings
  • X, Y and Z accelerometer readings
  • Temperature in Celsius


Windows Driver Software

Available here




Introducing Circuit Playground

Fabrication Print

Dims in inches

Introducing Circuit Playground

Key Parts and Components

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