It's amazing that you can buy a small computer like the Raspberry Pi for under $50. However what do you do with a small cheap computer like this? Make yourself a retro gaming handheld emulator of course!
There are many projects out there already that inspired me to make my own Raspberry Pi Handheld, but unlike mine many need tools that many people don't have easy access to such as 3d printers and laser cutters. I made mine to be made with the simplest of tools and minimal experience needed. This doesn't make it easy, but you should be able to pick everything up as you go.
Step 1: Get What You Need
List Of Needed Items
- Raspberry Pi (I used the Model B Rev 2)
- 8Gb Sd Card
- 3.5" Reversing Screen (If I were to do the project again i would use the 4.3" version)
- 2x 2000mah Power Banks
- Solderable BreadBoard
- 10 Push Switches (12 if you want left and right triggers)
- Two Way Switch
- GPIO Ribbon
- Wooden Box
- Sheet of 3mm Plastic
- An Old Controller You Don't Mind Breaking
- Few old usb cables one with micro usb connector
- Soldering Iron
- Hot Glue Gun
However if i were to do this project again i would change a few things. Firstly i would use the newer, better and faster Raspberry Pi 2 or the small and efficient Raspberry Pi Zero, if it wasn't so hard to get a hold of. This would give better performance in PS1 and N64 emulation which benefits from the better processor of the Raspberry Pi 2 or the higher clocked Raspberry Pi Zero. I would also use a 4.3" screen as there is plenty of room in the case to accommodate it, it is similarly priced and it gives you a bigger screen to play all your favorite games on. Lastly i would incorporate Left and Right Triggers and a Joystick instead of a D-Pad. These would give better game play in many of the games.
Step 2: Install Your OS
My Raspberry Pi Handheld uses the popular emulator software known as RetroPie. You will need to download to your computer from here. Once it is downloaded use Win32DiskImager to flash it to the SD card. You can download that from here. Once the installation is complete you can remove the SD card and put it into your Raspberry Pi.
Once you have inserted your SD card into the Raspberry Pi connect the Pi to a keyboard, monitor and power. When it powers up go through the input configuration process.
Once the Pi is booted connect it to the internet through either an Ethernet jack or a wifi dongle, however you would need to setup the wifi dongle. Once you are connected to the internet exit retropie by pressing the start button and selecting exit Emulation Station. Once you are in the terminal enter the command:
You should see an IP address come up. On your computer you can use a free software called putty(download here) to connect to the Pi and you can transfer Roms from your computer to the appropriate folder.
Once this is done you can test out some of your retro games using a keyboard or USB controller.
If you need more information there are plenty of tutorials on the Internet
Step 3: Modify the Screen
The screen runs of twelve volts but the batteries only supply 5 volts.
Firstly you need to dissemble the screen. To do this you need to unscrew the 4 Phillips head screws holding it in. One may be hidden under a warranty sticker. After the back is taken off you should see a circuit board connected to a lcd by a very fragile ribbon cable, DON"T BREAK IT! or else you will need a new screen. To fix the problem you need to get a multi-meter out. Probe around some of the pads that can be soldered to until you find one that has 5 volts. Solder two wires there and put a dab of hot glue to relieve strain of the soldered connection.
There is another thing we need to do with the screen, make it thinner so it fits in the case better. To do this you need to remove the three buttons used to control some settings of the screen. The easiest way to remove them in my opinion is just to use some wire cutters and trim the legs of them so they fall off.
You should now try to connect it the raspberry pi and power both of them on remembering both only can now take 5 volts!!!
For more information on converting the screen to make it work off 5 volts check out this forum.
Step 4: Time for Batteries
Its all good having the screen and Pi working together, but they can't be connected to the wall forever... TIME FOR BATTERIES!!!!!
Now i would say that finding and choosing the right batteries for this project was one of the hardest things to do especially when working with a budget like me. There are heaps of fakes all over the internet that are dodgy. However i found some power banks on special at a store. they where very cheap however low in amperage, they were only 1800mah, so i brought two. I opened them up and they turned to be 2000mah each which was perfect. The great thing about powerbanks is they already come with a charger and a step up converter meaning they are ready to go already. Anyway back to the instructions...
If you choose to go with one power-bank you don't really need to do much it is all ready to go!
If you have two or more power-banks like me you need to find two old usb cables you don' t mind breaking as you will need the remove the usb female connector from them. You will need as many of them as you have batteries. Insert the female connector into the male socket and connect the positive wires from both of them and the ground wires together to wire the batteries in parallel effectively doubling your play time. If you want you cant also find two micro usb female plugs and plug them into the male counterparts and wire them up to a female micro usb connector if you want to charge the whole unit with only one port. You can leave it like i did and just use two chargers to charge the handheld.
Step 5: Making the Controller
Its all good using a keyboard but we need a custom controller for our handheld
Firstly you need to take out the buttons, bread board and GPIO ribbon. You need to insert the buttons into the bread beard in the way you want them and cut the bread board to size. For my handheld i had four pieces of breadboard. On one i had the A, B, X and Y buttons, on another the D Pad and lastly two with single select and start button. Once you have soldered them in place you need to boot up your Pi connect to the internet, to a screen and keyboard and follow this tutorial from AdaFruit to setup the Pi's GPIO as keyboard inputs. Once you finished setting the Pi's GPIO it should look like the image above.
Now you need to wire the GPIO Ribbon to each of the buttons as you set them up. Make sure to do it correctly by testing it out on the Pi. If everything works put some hot glue on the wires holding them in place.
Step 6: Preparing the Case
Many other Pi Handheld use 3d printers and laser cutters especially when making the case. However i made mine using nothing but sanding paper, dremel, jigsaw and drill.
Firstly take all your components and check if they fit in the case and align them were you want. Outline all the ports using a pencil. Do this carefully and accurately. Now using a dremel cut out all the holes you marked out. Check if the ports fit in and if they don't make them bigger using the dremel and sandpaper. Insert all the components except the controls and screen in the bottom of the case.
Step 7: Wiring in the Case
Wiring; everyone's favorite part......
Firstly lets wire the screen and raspberry pi together. Underneath the rca jack on the Pi there are three solder points. You need the solder two wires to it, one for the composite data and one for ground. Now solder the other end of the wire to the composite solder point on the screen and the ground wire to the ground solder pin, pretty self explanatory.
Now to power everything through the batteries and adding a power switch. Get the power cable from the batteries usb port and solder it to the two way switch. Than solder another wire to the other pin on the two way switch and to the 5 volt connection you found on the screen. Yet again solder another piece of wire to the 5 volt connect on the screen and to a female micro usb connector that is plugged into the Pi. With the ground cable from the power bank solder it to the ground connection on the screen and the ground connection on the female micro usb connector. Check the diagram below if your not sure how to solder everything.
Once you finished wiring try powering the whole system off the batteries and hope it works. If it doesn't check your wiring again.
Step 8: Making the Front Plate
Now you have most components in place, but we still need the face of the unit!
Firstly i want to say take your time with this!!!!!! I had to redo mine as i firstly tried to do it quickly using a piece of plywood that was too small and in the end it looked horrible. So i had to spend alot of time taking it all apart again to make a better front plate this time out of a scrap piece of plastic with it better to work with as it is stronger, easier to work with and looks better in my opinion.
Before working on the front plate we need something to fit over the small buttons to make them look nicer and easier to press. This is were the old controller comes in place. I used an old SNES controller to source the d pad and the plastic button caps. Leave these aside for now.
We also need to remove the clear protective plastic from the top of the screen case. I took of the lcd from the top panel and put a bit of pressure on the clear plastic on top and it eventually peeled off. i cleaned the sticky glue of the plastic. The piece of plastic had a clear center and had a black outline around it which what good because it give some area to apply glue later on. Trace out the plastic from the screen on the plastic for the front plate and inside that rectangle trace out the lcd inside it. Cut out the trace from the lcd using a drill and jigsaw. you can make this slightly bigger as you will still be able to glue the clear and black plastic on as it is bigger than the lcd.
You can glue the clear plastic and lcd in place now. Now that you know where the screen will be you have align the buttons in the positions you want them. Take the circuit you made before and try tracing around the buttons. Using a drill you can create holes where needed. Lastly glue the control circuits in place and the button caps and d pad onto the buttons.
Step 9: Finishing the Case
Now that you have finished both halves of the case we now can finish up. Connect the GPIO ribbon to the Raspberry Pi and make sure all the power cables are plugged in and we can close it up. To close up the unit you can use hot glue, like me, epoxy or other similar glues. I wouldn't recommend screws as they could crack the wooden case.If you want you could also give the case a stain or a clear coat of varnish to protect it.
Step 10: Have Fun We Are Done
YOU HAVE COMPLETED THE BUILD, CONGRATUALTIONS!!
You can now relax and play all your old favorite games in a portable handheld device that you created yourself.
It is impossible to explain the feeling when you know that your playing on a device you created yourself and put many hours into.
I hope you found my Instructable useful and informative. This is my first Instructable and also my first major electronics project. If you have any questions or feedback you can ask me in the comments and i'll do my best to reply.
The dimensions of the finished system are 201mm x 81mm x 36mm.
The battery lasts me around 2 days of on and off use, but when running Metroid Fusion for the GameBoy Advance it lasted 4 hours.