Intro: Mini Joystick With Fire Button
This is a miniature joystick made from a few switches and a ballpoint pen. An optional fire button can be added if your pen is the clicker type. The action is very smooth and responsive. A bit of back story follows so feel free to skip it and get right into building.
Most projects start with an idea and then you source components to build it. This one started from a simple component which turned into an idea.
I had made a purchase from the Electronic Goldmine and got a free surprise box with my order. The box contained around 50 right angle switches amongst a lot of other goodies so I started thinking about what I could do with them.
It didn't take long before I came up with the idea of mounting four of the switches around a center point and using something to control them like a joystick. But what to use as the joystick? I rummaged through my junk pile and found half of an old pen, perfect.
I prototyped it out and it worked okay. The first thought was that it would be cool to have a button at the top of the joystick. I needed a better pen, the retractable type with a clicker. I built another version with the same electronics and a new pen. It was close but there were still some issues to work out. The third time was a charm and I'm very happy with the results. So let's get started.
Step 1: Gathering the Parts
What we'll need:
1) A pen, preferably the retractable type but just about any pen will do.
2) Four right angle push button switches.
3) A long screw, the smaller the diameter the better, and a nut to match. I used a 4-40 at 1-1/2 inches long. A 2-56 at the same length would be even better but I couldn't find one at the local hardware store.
4) A small piece of proto board.
5) Some hook up wire. The thinner the better.
6) Headers of some sort.
7) A small grommet (optional).
8) A round push button switch (optional, not pictured).
Step 2: Prepare the Switches
The switches don't quite fit in the protoboard in their default configuration but that's easily fixed. We just want to bend the mounting leads out and then down into a right angle. The leads already have a slight bend in the correct place.
Step 3: Mount the Switches
We want to mount the four switches facing in around a center point. Then drill a hole just slightly bigger than your bolt.
Step 4: Solder the Mounting Leads
Next we'll flip the board over and solder the mounting holes along with the headers.
Step 5: Solder the Connections
Now we're going to connect the switches to the headers. One leg of each switch will connect to a single header (white wire) while the other legs will connect to a single common signal pin (black wire). The signal pin can be connected to a voltage or ground depending on your application.
Step 6: Disassemble the Pen
Time to take apart the pen. Disassemble it completely and make a few cuts with a razor blade to prepare the joystick. I found it a bit hard to cut a right angle with the razor blade so ended up sanding the ends to straighten them out.
Put the two smaller pieces back together and hold on to the larger piece for later.
Step 7: Thread the Wire
There are a handful steps here but only a few photos. Make sure you have a switch that will fit in the pen body before proceeding. Otherwise you can skip to the last paragraph.
The first step is to cut off one end of the grommet so that it lays flat. Then punch a few small incisions on either side of it using a small flathead screwdriver or a razor. The grommet serves as a cushion for the joystick and prevents the pen tip from catching in the hole.
Next, run each wire through the grommet and through one of the holes in the perfboard (preferably not the large hole we drilled out earlier). The holes will probably need to be widened slightly depending on the gauge of the wire.
Next we want to solder each of the wires. Like the buttons before, the white one connects to it's own header and the black one to the common signal pin.
Now take bolt and flatten each side using a cutoff wheel or grinder. We need to make enough room for the two wires and the bolt within the pen body. The end result is that the bolt should be more rectangular than round. The bolt will still be able to screw on if we leave enough thread.
Lastly we want to thread the bolt and two wires through the body of the pen. This step can be a little tricky depending on the width of the bolt, gauge of the wire, and the diameter of the pen. Be patient if you don't get it on the first try, it took me several tries to get it right. Once the both makes it through you can put the spring and bolt on.
Step 8: Solder the Fire Button and Cap It
We're almost done. Now it's time to solder each of the wires to the button's leads. Once that's done give the wires a twist or two to pick up the slack and force the button into the end of the pen. Then put a stopper in the pen to provide a solid clicking surface and put the end on to seal it all up.
Step 9: Test the Circuit
The joystick is now done so it's time to test it out. This test circuit connects each of the LED anodes (the long lead) to each of the button pins. The cathode of each LED (short lead) is connected to the signal pin.
The button pins then connect to the positive terminal of the battery while the signal pin is connected to the negative terminal. Activating each of the buttons will complete the circuit for a single LED.