In this Instructable, I'll be going over how I made a flashlight inside of an NES controller. This flashlight uses a single LED powered by a rechargeable lithium ion battery. Both the battery and the controller were leftovers I had lying around from previous projects, so it was a great way to combine and make use of waste.
If you have any broken or spare controllers, this is a nice project to give them some new life. You could also use similar-sized controllers like the SNES.
The basic construction is to put the LED in the hole originally used for the cord. The circuit will then mostly reside inside of the controller, with a switch and a charging port on the outside. I had to add holes for these.
Step 1: Tools and Materials
- NES Controller
- Battery charger
- Super bright white LED
- Philips head screwdriver
- Soldering iron and solder
- Hot glue gun
- Wire strippers
For the battery and charger, I got these from a cheap bluetooth speaker from a previous project, but you can find batteries and chargers on sites like Sparkfun and Adafruit. The smaller (physically) you can get for each, the better. I used a 5 V battery but you can light the circuit with 3.3 V.
This project assumes basic soldering skill and familiarity with basic electrical circuit terms.
Step 2: Disassembling and Making Space
I forgot to take pictures of all the disassembly steps, but it's pretty straightforward. Just remove the screws from the back and pull out the board, buttons and button pads and keep in a safe place. You can snip the wire, or desolder it if you really want. We will end up desoldering it later on, but I snipped mine earlier since the controller was already non-functional.
With all of the internals removed, I then took out many of the plastic pieces to maximize space internally. As you can see in the picture, essentially I took out everything but the four corner screws (I was already missing two anyway) and the bottom posts that attach the button pads. I took these out by grabbing with needle-nosed pliers and bending them off.
Step 3: Getting an Idea of Fit
The next step was to make sure I could fit everything. I put in all the buttons and pads along with the charging circuit (this is actually the whole speaker circuit, so if you buy a specific charger you might be able to find something even more space-efficient). After that, I put the original board on top, with the battery on top of that, and then made sure it could close. Somewhere during this step I also desoldered the IC and the remaining pins for the cord from the board to maximize the space.
If you're having problems with the fit, you could try modifying it. You could remove the OEM board and place in some other rigid backings behind the button pads. I've also seen other NES controller projects where the maker glues in the buttons. I went with the original pads and board since the fit worked for me, and I also wanted all of the buttons to remain pressable (but please note they have no function).
Step 4: Preparing Holes for the Switch and Charger
I needed to make some space for the charging port and the switch to stick out of the top. First I attempted to crudely trace around them with a pen, which sort of worked as you can see in the picture. Then I used a drill to make a few small holes inside of these traces. After that, I used files to expand the holes until they were big enough.
The result is shown in the second picture. The switch ended up a bit closer to the board than I wanted, so I trimmed off the left lead to avoid possibly shorting it to the charger board. I used an SPDT switch here since it's what I had available, but it only needs SPST.
Step 5: Building the Circuit
The basic circuit for this is a simple switched LED setup with a current-limiting resistor, as reflected in the schematic. I like to use this site to find the minimum resistance value, although I ended up choosing my own value that I felt was suitable. This is where a protoboard is handy so you can quickly check out different resistance values and get an idea for how the brightness is affected. I ended up choosing 680 Ohms.
The charger is not reflected in the schematic, as its exact function is not particularly relevant to the function of the flashlight. Essentially it is a different circuit connected in parallel across the battery which should have no effect on the flashlight function, but please make sure the switch is off when charging.
I started off by putting the LED, resistor and switch in place in the controller just to eyeball how much length I'd need for each. Since space is limited you don't want to be soldering the leads of the resistor or LED near the ends; you'll want to be able to trim some off. One end of the resistor goes to the right lead on the switch, the other to the LED anode, which is the longer lead.
Now is a good time to mention that you might want to file down a small part of the hole for the LED so that it doesn't get crushed when you put it together.
Then I connected the middle lead of the switch to the positive terminal of the charger, and the negative terminal of the charger to the cathode of the LED. I used hot glue to help secure these. Finally, with the battery, I had just enough length on its existing wires to feed them through one of the existing holes on the controller board, and solder the wires respectively to the positive and negative charger terminals.
Step 6: Finished Product
Once the circuit, buttons, pads and board are in place, put the controller back together and make sure it turns on! On second thought, you probably should make sure it turns on before you fully reassemble it, but make sure you also turn it on at least once when you're done (otherwise why did you make it?).
Unfortunately it's difficult to capture the brightness in photos, but I have a photo showing it on/off to prove that it works.
Step 7: Conclusion
I hope this Instructable was informative/helpful, and perhaps will inspire you to make your own variation. I'd love to see somebody take it on with AAA batteries, or incorporate the existing buttons.
While making this, I thought that the idea of a rechargeable flashlight was an interesting concept. As disposable batteries increasingly fall out of usage, it is tempting to want all portable devices to be rechargeable. However, if you were relying on a flashlight in an emergency, you would want to easily be able to pop in fresh batteries. Perhaps one day I might try my hand at one that accepts both types, or you could do it for your own variation!
If you have any ideas, please leave a comment, and if you liked this Instructable please vote for it in the Game Life Contest! Thanks for reading!