In this project we’re building a DIY gamepad using the Bluefruit EZ-Key module and a 3D printed case.

The Bluefruit EZ-Key HID keyboard controller is a bluetooth breakout design for making DIY keyboards and game pads. It’s requires no programing and works with just about any trigger or push button. It takes up to 12 inputs and can be powered with any 3-16 VDC.

The Perma-Proto comes in different sizes which is perfect for making all sorts of projects. The ½ sized Perma-Proto breadboard is like a business card and which makes it perfect for making a small game controller.

Prerequisite Guides

We recommend walking through the guides below - these will help you get familar with the components used in this project.

• Introducing EZ-Key Bluefruit
• Adafruit Guide to Excelllent Soldering

Expectations

This is a project that requires a bit of soldering and wiring - It's great for getting practice and well suited for makers with intermediate soldering skills. It's not the easiest 'first-time' beginners project, but it can be done if approached with patience, ambition and positivity. The 3D printing takes 2-3 hours and costs about $1.50 in material. If you don't have access to a 3D printer, check with your local hacker/maker space, library or community collage - they just might have one! Have fun, and happy making!

Parts

The parts are available in the Adafruit shop and listed on the right sidebar. Take a moment to look over each components.

• Adafruit Perma-Proto Half-size breadboard PCB
• Bluefruit EZ-Key
• Micro Lipo w/Micro USB 
• 500mAh Lithium Polymer Battery
• 6mm Buttons
• 12mm Buttons
• Slide switch

Tools & Supplies

You'll need some hand tools, a soldering iron, 3D printer, wires and other maker tools and suppilies. 

• 3D Printer
• Soldering Iron
• Wire cutters + strippers
• 30AWG Silicone Coated wire
• PLA+Semiflex filament (3mm/1.75mm)
• Panavise Jr. + Helping third hands
• Heat Shrink Pack
• Blue painters tape
• #4-40 3/8 flat Phillips machine screws

Take a moment to review the components in the circuit diagram. This illustration is meant for referencing wired connections - The length of wire, position and size of components are not exact. 

The 500mAh lithium polymer battery is connected to the microUSB lipo charger via JST cable. The Bluefruit EZ-Key has VIN pin connected to a slide switch. The BAT pin on the micro lipo charger is wired to the slide switch. The ground pin on the Bluefruit EZ-Key is wired to the GND pin on the micro lipo charger. 

A 6mm tactile switch is wired to pins 3V and PB on the Bluefruit EZ-Key to serve as a bluetooth pair button.

The 6mm and 12mm tactile button inputs are wired to input pins 0-7 on the Bluefruit EZ-Key. Each tactile button has ground connected to ground rails on the Perma-Proto PCB.

The 1/2 sized Perma-proto breadboard PCB will house the 8 momentary push buttons. The right-side of each buttons will act as the ground connection. Each of the buttons right terminal are wired to the ground rail. The two ground rails are wired together. A single wire for the ground connection is wired to the Bluefruit EZ-Key. Each botton left terminal has a wired connection to the input pins.

The input connections on the Perma-Proto should preferably be made on the back of the PCB and close-to to terminal, not actually on the same through-hole. 

Be very aware and cautious when wiring these connections. It's easy to get lost and loose your place/spot while soldering. Always double check your connections before you solder!

Parts & Settings

Printing Parts

The enclosure parts can be printed in PLA or ABS filament. PLA material tends to have less warped corners. We printed out the controller buttons in TPE filament, which makes them flexible and rubbery. No support material is required for the parts.

STLs are oriented to "print-as-is". Our recommend slice settings work well with Printrbots and Orion delta machines.

Prep Slide Switch Wires

Start off by prepairing the wiring for the slide switch. You'll need to measure two pieces of 30AWG silicone-coated stranded wires to about 10cm long. Strip both ends of the wires and apply solder to 'tin' the tips - This helps prevent the stranded wires from coming apart. 

500mAh Charging Rate

You'll want to up the charging rate on the Micro Lipo charger. To make it safe for all our batteries, we set the default rate to 100mA. You can easy up the charge rate to 500mA by connecting the solder jumper . This will allow the 500mAh lithium polymer battery to charge faster. Melt some solder onto the jumper to close it and set the new charge rate.

Wire Slide Switch to Lipo Charger & Bluefruit EZ-Key

Secure the micro lipo charger PCB to panavise Jr. Apply solder to the BAT and GND pins. Now solder one of the wires from the slide switch to the BAT pin by heating up the pin and inserting the wire while the solder is hot and molten. Repeace this process for the VIN pin on the Bluefruit EZ-Key.

Prep Ground Wire

We'll need a wire to connect ground to the Micro Lipo charger. Measure and cut a piece of 30AWG silicone-coated stranded wire to about 5cm long. Strip and tin both ends of the wire.

Wire Ground to Micro USB Lipo Charger

Secure the lipo charger PCB to the Panavise jr. Solder the ground wire into the GND pin. Double check connection by tugging on the wire, ensuring a solid connection. Remove from Panavise jr. when complete.

Wire Ground to Bluefruit EZ-Key

Secure the Bluefruit EZ-Key to the Panavise jr. Apply solder to the G pin and insert the remaining end of the ground wire while the solder is moltent. Double check connection is solid. Remove from Panavise jr. when complete.

Wired Power Circuit

Double check your work. The power circuit is now complete! Next step is to plug in the JST cable from the lithium polymer to the lipo charger.

Test Power Circuit

Plug in the JST cable from the 500mAh battery to the JST port on the lipo charger. The slide switch will power on the circuit when the switch is set to the farthest terminal with the wire connection. If the LED lights on the Bluefruit EZ-Key, everything is good!

If the LED doesn't power on, double check your wiring. The battery may be drained, so check that too!

Prep Perma-Proto Half-size PCB

In this project, we're using the half-size perma-proto PCB. We'll add the buttons with the PCB oriented with the labels right-side up.  

Installed buttons

Double check your buttons are properly oriented and exactly in the right spot! You can follow the photo and circuit diagram to cross reference the button placement.

Saw bottom corners from Perma-Proto PCB

Next up, we'll need to remove the bottom left and right corners from the Perma-Proto PCB. I recommend using a rotary power tool like a DREMEL. You're going to need to do this in a well ventilated area. You're also going to need to wear safety glasses. I recommend using a 'thin cut' attachment.

Trimmed Perma-Proto PCB

You're going to want to trim off the power+ground rails from pins 1-2 and 29-30. We won't be using these in this project, so it's OK to remove them. 

Ground Wires

Here's the full set of 30AWG silicone-coated wires all cut and tinned. They're short and thin!

Button Ground Placement

Insert each ground wire into the through-holes before soldering into place. You'll want to assess the placement and double check the front and back of the PCB. In this project, I'm using the right side of the buttons terminals as the ground - so all of them need to be this way. Note, once the PCB is flipped over, the 'right-side' becomes the 'left-side'. Take this in consideration, as it can start getting confusing. I myself had to resolder a few times!

Soldered Ground Wires

And now we have ground wires! Double check your connections and ensure the polarity of each button is correct. If you managed to miss one, go back and heat up the pin, remove wire and try again. The Perma-Proto PCB has a high quality solder mask and copper through-holes, so you can do several attemps. 

Wired Buttons to Bluefruit EZ-Key

And now we have the button inputs wired to the Bluefruit EZ-Key, yay! You'll want to, yet again, double check your connections to ensure everything is right.

Soldered Inputs to Bluefruit EZ-Key

And now we have a complete circuit! 

Heat Shrink Input Wires

Let's go ahead and make the wiring from the button inputs a bit more organized. Cut a piece of heat shrink tubing and split it down the middle. Bundle up all of the input wires and wrap the piece of heat shrink around the wires. Apply a bit of heat to seal the heat shrink tubing.

Now we can mount the components to the enclosure!

Mount Bluefruit EZ-Key to bottom cover

Now we have both components mounted to the bottom cover.

Plug in 500mAh Lithium Polymer Battery

OK, now is a good time to plug in the JST cable from the battery to the JST port on the micro USB lipo charger.

Insert 500mAh battery

We need to insert the lithium polymer in between the Perma-Proto PCB and the bottom cover. There should be enough clearance for the battery. You'll want to arrange the wires so that they aren't being kinked or scrunched up.

Install Ninjaflex buttons into case

Before we insert the circuit into the top enclosure, add the ninjaflex rubbery buttons to the enclosure. These need to be in place before the circuit is installed.

Fasten bottom cover to case

Insert four #4-40 3/8 flat Phillips machine screws to the corners of the bottom cover. Fasten all the way to tighten and completely close the enclosure.

Charge Battery and Play!

And thats about it! The circuit is finished, project assembled and ready to play! Or is it? I recommend fully charging the 500mAh battery before playing. Plug in a micro USB cable to the lipo charger. The charger has an on-board LED indicator that lights green when the battery is fully charged. Red LED indicates the battery is charging.

Changing Button Mapping

Check the EZ-Key introduction guide for button mapping details!

Pairing with Devices

A freshly baked, 'never-been-used' Bluefruit EZ-Key will automatically start searching for a device to pair with. Your bluetooth enabled device should pick up the EZ-Key within a minute. If you're having issues with pairing, or unfamiliar with pairing bluetooth devices, you should check out the pairing page on the EZ-Key introduction guide.