How-To: Analog control stick for your Sony PSP
Every so often, that console-modding Benjamin Heckendorn wanders away from his lair at benheck.com to share some interesting projects with Engadget.
History is littered with game systems using far-too-stubby of controller sticks. From the Intellivision's "disc of doom," to Coleco's "shaft of stiffness" (quiet, you!), and even now, in this high-tech age, the Sony PSP's "sliding nub of death." It's unfortunate that the PSP is saddled with that thing -- it's a pretty slick system otherwise, with a library of almost 5 games! (Please don't key our cars.) Well what if you could augment that sliding nub with something more useful, like an actual analog control stick? Well now you can!
In part 1 of this article we'll show you how to wire up an analog stick (from a PS1 / PS2 Dual Shock controller or an original Xbox controller) to your PSP. It's a lot easier than you might think. In part 2 (coming soon) we'll walk you through making a swell "clip on" joystick enclosure for the stick (or you can simply roll your own in the mean time). Ready to do this thing? Get in there!
For part 1 of this project we're going to learn how to attach an analog stick to one of the PSP's internal circuit boards. You can then use this info to build a custom joystick "clip-on" device yourself, or use the steps that will be covered in the upcoming part 2 of this project.
Parts you'll need:
PSP unit (durr)
A sacrificial analog controller. Useable, tested types include Dualshock (PS1 or PS2) or original Xbox controllers. Third party controllers should also work. If you've ever smashed a controller against the wall in rage and it's still laying around in a junk drawer someplace, it's a perfect candidate -- just use whichever analog stick is the least damaged.
Some thin wire / ribbon cable, 4 pieces about 6-inches each. I highly recommend IDE hard drive cable as it's abundant and easy to use. The thinner type with a blue plug on one end (used on ATA-33 and higher drives, inside most PC's since 2000) is ideal, especially if it's solid thin wire instead of stranded. Test: If you bend it and it sort of holds the shape then it's solid wire. Also with ribbon cable you can cut off a section containing the exact number of wires you'll need - in this case 4.
Tools you'll need:
15 watt small soldering iron with a nice, new sharp tip. A larger, higher heat one (those usually run at about 40 watts) will also work though you'll just have to be more careful not to melt things into oblivion.
Desoldering iron or desoldering braid. Not as common in a household as a soldering iron, but if you're the least bit into electronics tinkering you owe it to yourself to drop $10 and grab one from Radio Shack. For a cheaper one-time solution you can get desoldering braid for about $4 at the Shack as well. We'll discuss how to use these when the time comes.
Some solder, the thinner the better. (You're not exactly doing copper plumbing here.)
Wire snippers, scissors, anything that cuts.
Small Phillips-head screwdriver. "Jewelers" screwdrivers or the kind that come in glasses repair kits work well.
Other tools that will be helpful, but not essential:
X-Acto knives
A Dremel cutting tool
Needle-nose pliers
Small flat-tipped screwdriver
Definitions of terms I might use:
PCB - printed circuit board.
Potentiometer - a variable resistor (used in analog control sticks)
Step 1 - Get an analog stick
Ok let's do this thing! Let's get our new analog stick first. Open your sacrificial game controller case using a Phillips screwdriver and pull out the circuit board. While they all vary slightly, the analog sticks are almost always square metal boxes with a tact switch on one side for the click-down function. You should see two little boxes on other sides, and one side is empty. These two little boxes contain the XY stick-sensing potentiometers (variable resistors, like the volume on your boom box back in the 80's) and are the things we'll be wiring to the PSP.
Here's probably the trickiest part of the project for a beginner - we'll need to remove the analog stick from the controller circuit board. There are a total of 14 pins holding it in (4 frame posts, 4 for the switch and 6 for the potentiometers) All of them will need to be desoldered before the analog stick can be freed of the board. Skip ahead if you can handle this yourself, for everyone else, here's how:
Via desoldering iron - Plug the sucker in and let it heat up, usually five minutes will do it. Squeeze the bulb tight (blow out the air), then press the tip hole over the pin to be desoldered. Let it sit for about 3-4 seconds to heat up the solder, then quickly release the bulb. It should suck most of the solder off the pin. Generally if you can see a black hole around the pin you're good to go. Use a pair of needle-nose pliers or a small screwdriver to push the pin around, breaking it free of any remaining solder bonds. If the pin can be moved / bent you're good to go.
Tip: If you don't get all of the solder out of the hole the first time, it's actually helpful to melt solder back INTO the hole before trying to suck it out again -- new solder can help grab older solder. In fact, I usually add a little new solder to old joints before even attempting to desolder them.
Via desoldering braid - Desoldering braid is actually made from finely woven copper strands. This makes it "super solder absorbent!" To use, set the end of the braid over the pin to be desoldered. Next, press down on it with a soldering iron or other heat source. (A 40 watt iron will work much better than a 15 watt in this case.) Keep the heat and pressure on it for about 3-4 seconds -- you'll see the solder flow up into the braid after a bit. Pull the braid off and check the pin (as described above under "desoldering iron method"). As with the desoldering iron, adding a bit of new solder can often help your work.
Shown below are the pins on the base of an analog control stick, several of them on the right have been desoldered.
Once you have all 14 pins desoldered, rock the analog stick assembly back and forth to break it free of the circuit board. You can also cram a thin screwdriver under it and twist. If you have trouble removing the stick you can snip off the pins, just try to preserve the 6 potentiometer pins as best you can. Once it's removed we're ready to move onto step 2!
Step 2 - Open the PSP
Time to crack open your beloved PSP. The unit comes apart "from the front" that is, you remove the faceplate to get at the guts. Luckily we don't have to go very deep inside the unit to do this hack. Perform the following:
Flip over the PSP, screen side down. Do this on a soft cloth or mousepad to protect that amazing screen. Remove the battery cover and battery.
Viewed from the rear, there are a total of seven screws holding the face plate on. Four in the battery compartment on the left, two on the right and one at the bottom edge of the unit near the bar code. Remove all these screws. You may have to peel up some warranty-voiding stickers near the battery to find them all.
Note how two of the screws are silver colored and shorter. Be sure to put these back in the same holes they came from to avoid problems.
Flip the unit back over, screen side up. You should now be able to lift the faceplate off. The D-pad, analog stick, buttons under the screen and triggers will come with it. If the shoulder buttons pop out of place simply shove them back in.
Tip: Take care to keep the inside of the screen-protecting plastic clean and dust free. A soft, non-lint cloth, such as those used to clean glasses or camera lenses, works great for cleaning the plastic and the screen itself when it's time to put it back together.
You'll probably want to spend a minute or two gazing at the guts of the PSP. Once you're done with that, take a look at the underside of the faceplate.
You'll see the analog nub circuit board as shown above. Connect 4 wires as follows:
Put a small bit of solder on the right side of each of the connection pads (Labeled A, B, C and D in the insert) Keep the solder to the right of the imaginary green line drawn in above. If solder gets too close to the holes the PCB won't make contact with the rest of the unit when screwed back together and your analog stick won't work. If you do get solder on the left side of the pads you can remove it using the desoldering tools.
Attach a wire to each of the pads and string the wires to the right. In the photo you can see I've used thin, solid strand IDE ATA-33 hard drive wire. This works best and, since it's a solid strand, will stay in any position you bend it.
For best results, run the wires as 2 sets above and below the center of the circuit board. This allows the raised aluminum piece on the other half of the unit to fit between them.
Label the opposite ends of these wires A, B, C, and D to match which pads they were soldered to. (We'll use this letter code when wiring the new analog stick) I usually put small pieces of clear tape on wires to label them.
Make a small cut in the edge of the faceplate in the area circled in the photo. This can be done using a Dremel cutting tool, X-Acto knife or even the soldering iron if you don't mind toxic fumes. All you need is a small groove big enough so the four wires can snake out with the case closed.
Tip: Make sure the wires don't get in the way of the D-pad's rubber backing
Once you have this wired up you can go ahead and put the PSP back together (simply follow the directions in reverse, or hold this website up to a mirror). It may take a few tries to get the case to snap back together probably, just keep adjusting the position of the wires until they fit. If you arrange them as shown in the photo you should be ok right out of the gate. You may also need to adjust the size of the wire hole.
Step 3 - Wire the new analog stick to the PSP
So now you're sitting there and your PSP has wires dangling out the side... don't worry we're almost there. Let's connect the analog stick using the following diagram and instructions:
Solder the four wires (A, B, C, and D) coming from the PSP to the spots indicated on the bottom of the analog stick. Keep in mind this is a drawing of the stick from the bottom, and we're considering the side of the stick with the button to be the top.
Attach 2 "jumper" connections as indicated by the red lines. You can twist these wires together with the connections on A and C to make soldering to the pins easier.
With those connections made you're ready to test the new analog stick! Boot up your favorite game that uses the analog control (Or the one with the shortest loading times - your call) and test it out. If done properly the new analog stick should perform like a normal controller, and the built-in analog nub should still function as well.
Troubleshooting
Possible problems and likely solutions:
Directions are flipped - Check to see if you didn't get the wires switched around, you know A instead of C or something like that. Or you may be holding the analog stick the wrong way, try rotating it.
The new analog stick nor the original analog nub work - Very likely the main PSP circuits aren't contacting the analog nub's PCB. Check that the wires are bent out of the way of the aluminum piece that fits in the middle of the nub's PCB, and that the case is closing fully and tightly screwed. If the case doesn't close fully it can't make contact with the analog stick (.r any of the buttons).
Erratic movement - Check that the case is closed fully, allowing proper contact.
Conclusion
You now have the leet skillz to attach an analog control stick to a PSP. In part 2 of this amazing saga (coming soon to a website near you -- namely this one) we'll describe a way to make your own custom "snap on" enclosure for the stick so it doesn't look like a dangling pile of crap. In the meantime, feel free to come up with your own custom attachments using this mod. Have fun and go nuts!
