Drachenberry Pi: Dragon Mountain Design

As mentioned at the end of my last post, Adafruit did indeed figure out how to get RetroPie to work using their TFT screens, which was awesome, because it allowed me to use the one I had previously purchased without issue, and finally build my own GameBoy.

Parts List:

• Raspberry Pi A+

• 2.8″ TFT Touch Screen – Adafruit 1601

• PowerBoost 500 Charger – Adafruit 1944 (Haven’t tried it, but item 2465 might be better for this.  Also, hold onto that female USB connector.  We’ll use that too.)

• 3.7V 2500 mAh LiPO Battery – Adafruit 328 (Had a few issues with this for some reason and eventually switched to item 353, which changed up the aesthetics of the project a bit.)

• Perma-Proto Half-Sized Breadboard – Adafruit 571 (If you purchase everything on the list at the same time, you might get one of these thrown in for free… at least I did.)

• 12mm Tactile Switch Buttons – Adafruit 1119 (You’ll use four of them for this project.)

• 6mm Tactile Switch Buttons – Adafruit 367  (You’ll use four of these also.)

• 6mm Slim Tactile Switch Buttons – Adafruit 1489 (Used two on the TFT.)

• SPDT Slide Switch – Adafruit 805

• Female-Female Jumper Wires – Adafruit 266

• USB Type A Connector – Adafruit 1387

• Heat Shrink Tubing – Adafruit 1649

• Wifi dongle for Raspberry Pi.  I used Adafruit 1012, but there are others

• 6-32 x 1″ Flat Head Philips Screws – McMaster 91771A153 (You’ll use two of these, so unless you’re going to use them for other things, you can probably grab similar parts at Home Depot, Lowes, etc.)

• 6-32 x 1 1/4″ Flat Head Philips Screws – McMaster 91771A155 (Four for this project.  Can also be found elsewhere.)

• If you’re going for the larger battery from Adafruit, you’ll need two 6-32 x 3/8″ Flat Head Philips Screws – McMaster 91771A146 (I couldn’t find an equivalent at Home Depot… Used 1/2″ instead.  Bleh.)

• 6-32 Hex Nuts – McMaster 91841A007 (if purchasing screws elsewhere, the nuts may come included in the packaging.)

• 2-56 x 1/4″ Pan Head Philips Screw – McMaster 91772A077

• 2-56 Press-Fit Insert for Plastics – McMaster 92395A111

• No. 2 Lockwasher – McMaster 92146A520

• Micro SD card

Helpful Tools:

• Soldering Iron

• 3D Printer (or printing service.)

• Dremel (Rotary or MultiMax)

Alright! Let’s get down to business!

Set up the Raspberry Pi

Adafruit published THIS guide a while ago covering how to configure your setup to run RetroPie with the TFT screens.  At the time of posting, it seems that the guide needs to be updated, but when I started this project, it worked flawlessly.

The guide doesn’t really cover setting up over WiFi, so if (like me) you don’t have a model B, or B+ lying around, you can find more information on that HERE.

If all goes well, you should be able to fire up RetroPie.

Configure Button Inputs

While we’re already digging around in the shell, go ahead and download Adafruit’s Retrogame software.  My setup for mapping the buttons to their respective GPIO pins is below.

Feel free to change it up as you please.

Prep Perma-Proto boards

This is where the Dremel comes in handy.  Hack up the boards to the sizes/shapes below, and open up holes with a 2.5mm OD drill bit.

Solder-up The Switches

Solder the wires to the back of the boards using the images below as a guideline.

Solder the slim-tactile switches to the TFT in these two locations.

Build the Power Circuit

Connect the PowerBoost to the Pi and the SPDT switch as in the diagram below.

Build USB Extension

Solder the female USB connector that was included with the PowerBoost to the gift that keeps on giving (talkin’ 'bout you, Perma-Proto board), and wire that to the male connector.

3D-Print Housing and Buttons

Files can be found on my Thingiverse page HERE.  The housing components are designed to print without support and the default PLA settings in Cura.  For most of the buttons, I used NinjaFlex SemiFlex material (which you can now purchase in ‘sample’ quantities from Printrbot).

11/13/2015 UPDATE:  Files can also be found on YouMagine and Cults3D.  If you’ve enjoyed this project, and feel so inclined, consider sending me some love via a donation on Cults3D.  No pressure though.

5/18/2016 UPDATE:  Very proud to also have this work on MyMiniFactory!  Still free to download.  Tip me if you dare.

Prep Housing for Hardware

Hex nuts should snugly fit into all their designed crevices.

Install press-fit inserts into the holes as shown (holes may need to be opened up slightly depending on how the print turned out).

Final Assembly

**REMOVE THE SD CARD FROM THE PI BEFORE ASSEMBLY**

Fit the bottom components together, insert the SPDT switch, and screw the Pi, PowerBoost, and USB extension onto them.

Fit the top components together, place the D-Pad, Start, Select, A, B, R & L buttons into their respective locations, and screw down the Perma-Proto and TFT boards.

Connect all of your wires to the GPIO pins on the Pi.  You’re going to want to remove the plastic housings from the connectors on the wires and instead cover them with heat shrink tubing.  Otherwise they won’t fit when everything comes together.

Cover the battery with a layer of electric tape, connect it to the PowerBoost, and carefully sandwich it between the Pi and TFT as you line up the pins and close the housing together.

Insert your SD card, flip the SPDT switch to make sure everything works as intended, and secure the housing together with the 6-32 screws.

If You Use the 353 Battery

The hex nuts slide into their spots from inside the battery housing extension.

Place the faceplate within the extension, mount the battery within, and screw the extension to the main component of the main housing base (DBP-3001-01 instead of DBP-3001-00).  Make sure the wires and connector of the battery are accessible and can reach the PowerBoost.

The rest of the build is more-or-less the same.

Play Your GameBoy

Hello, old friend!