I decided to go as a Ghostbuster for a fancy dress party recently. Of course all Ghostbusters need fully working Ghostbuster proton packs complete with animated LED displays and electroluminescent glowing wires, so here are the details on how I built mine. It took about 3 or 4 evenings to build and involved Arduinos, lots of hot glue and over 92 LEDs! It is just a shame I missed out on the best fancy dress award that night because it looked ‘too realistic’!
It probably helped me considerably that for years I’d been making, repairing and hacking remote control model aircraft. At least I could put to use all those countless hours burning my fingers with soldering irons and all the experience learning what happens if you don’t glue enough in the right spot of your model aircraft. If I hadn’t of had this experience it probably would have taken me a lot longer so please bear this in mind if you try to make your own. If this is what you decide to do, make sure you research everything fully and how to use the tools safely.
What is a Ghostbuster Proton Pack?
In the film, a Ghostbuster Proton Pack is a portable nuclear device the size of a jet pack that sits on your back capable of banishing ghosts back to another dimension. It’s mounted on an ALICE frame which is a special kind of military harness and frame system designed to carry heavy loads and has a gun-like hose attached to it so you can control the energy stream.
For my version I decided to create a light-weight version of the Alice frame out of PVC pipe and some military webbing straps I bought off Amazon. I also decided that to aid portability I wouldn’t make the gun part and instead hostler the hose to the pack, great for durability, especially when dancing as is required at any decent party! The back of the pack extends out a bit and contains numerous extrusions, connectors and raised parts which all good technical devices must have. From the back of the pack the energy hose extends out, loops under the pack and is holstered at the side.
What I needed
- PVC pipe
- PVC L-bend connectors for pipe x4
- PVC 132 degree bend suitable for 32mm or 50mm pipe
- 1 gang flush metal electrical box
- 2 gang flush metal electrical box x2
- Hot glue for glue gun
- Foam board (A3 size) x2
- Gorilla Tape
- ALICE belt braces/suspenders from Military store
- Corrugated tubing or cable tidy tubing
- Black enamel spray paint
- Small plastic cable ties
- Electrical insulation tape
- Arduino Battery adapter cable for 9v battery
- Arduino Uno – 5V
- Adafruit 1.2″ 4-Digit 7-Segment Display w/I2C Backpack – Green
- Adafruit 1.2″ Mini 8×8 LED Matrix w/I2C Backpack – Green
- Jumper wires – female to male suitable for 0.1″ headers
- Green electroluminescent wire with pocket inverter
- Blue electroluminescent wire with pocket inverter
- Cable cutters
- Wire strippers
- Stanley knife
- Cutting board
- Soldering iron + solder
- Hot Glue Gun
- Dremel with circular saw attachment
- Plastic dust sheet
Try to save these before they go into the rubbish: –
- Corrugated mailer box just a bit larger than a stack of DVDs
- Plastic food packaging such as yoghurt pots and snack sausage containers
- Plastic milk bottle lids
- Plastic tray from packet of biscuits
- Small plastic water bottle
- Circular Plastic sweet tub
- Tassimo coffee pods
- Foam coffee cup
Building the motherboard and ALICE frame
The first part I started on was the motherboard which everything else mounts or sticks to. This was created by sticking two lengths of foam board end to end using Gorilla tape and cutting out a template. I repeated this and then rotated one end of the foam board 180 degrees and laid it on-top of the original piece to create a 2 layer foam board sandwich. As the joins have been flipped it makes a nice stable one. I then used a tiny bit of hot glue to sandwich the boards together and then using a pencil sketched a circle that was 6cm larger in diameter than the plastic sweet tub over the bottom of the foam board.
Next I used my Stanley knife and cut along the outline I’d just made. I had to use the sandpaper attachment of the Dremel to clean it up a bit but it was starting to look like a sturdy base for my pack.
Now I had my motherboard, I had to decide what to put on it. After laying out what I had salvaged from my recycle bin, I also grabbed the metal electrical boxes and wrapped Gorilla tape around the width. The key here is that exposed metal makes everything look very realistic so I tried to be neat but expose as much detail as possible at the same time. Additionally I placed down my plastic sweet tub, spray painted each part I wanted and once dried, hot glued everything in place. It was starting to look good!
The ALICE frame
I made the frame from PVC pipe but rather than build a real ALICE frame, I just made a simple rectangle one by using the Dremel to cut 2 lengths of pipe that were a little less than the width of my motherboard, another 2 lengths that were a little less than the height of my motherboard and used the hot glue gun to join the lengths together with the PVC L-bends (the L-bends add some length on so that’s why you should make the lengths a little less). When you’re done you should have a PVC frame that is the exact size as the motherboard. Now would also be a good time to spray paint the base and leave it to dry.
Attaching the base and harness
The harness webbing I purchased from a military store on Amazon. It was an actual pair of ALICE frame braces. The connector for these looked way too much for what I needed so I cut it away from the top of the braces leaving the distinctive upside-down ‘Y’ shape. I then reversed them so I had the Y shape pointing upwards and taped the bottom of the Y to the middle of the motherboard with considerable amount of Gorilla tape – this is where Gorilla tape shines because it is super strong. I made sure I taped long strips across the whole of the motherboard as it helped distributed the weight. Remember the PVC rectangle frame will take a lot of the load too, this happens because the next step is to lay the frame over the top of the webbing and motherboard while taping the vertical sides of the frame to the vertical edges of the motherboard – sandwiching the harness between them while making sure the top of the motherboard and webbing were free of tape. I then pulled the two ends of the Y braces over the frame and using cable ties and more Gorilla tape secured each end to the respective bottom corner of the frame. It sounds complicated and is even more complicated to type out but you should now have a pack you can put on your back and walk around comfortably with.
Finally I cut a length of corrugated tubing, securing it to the motherboard and detailing with hot glue and cable ties. Finally using my plastic biscuit trays I covered up the ends using more hot glue (they were white chocolate Rounds if you must know)! I also used tiny cable ties to secure the tubing to the ALICE frame which really helped with the structural integrity as well as give it a true homemade prototype feel to it (you can see this in the photo above).
Soldering the electronics
This was the fun part, using the instructions provided by the Adafruit kits I quickly soldered all the header pins and the LED segments to their respective boards. I did change an IC2 address because I had both a 7×4 segment display and a 8×8 matrix but it covers this in the kit. The IC2 address needed to change because rather than have two wires for each LED, the kits allow you to use 4 wires to control all these LEDs – pretty smart I think!
Coding the Arduino firmware
With the Adafruit kits soldered and wired up to the Arduino using the jumper wires, I plugged in a USB cable and quickly wrote some software to animate the displays. It cycles between jumping down to 1985 (the theme of the party was 1985), animating a ghost character and detecting ghost levels with a simple sine wave function.
Now with the code written I quickly tested it and hot glued the kits to foam board frames before mounting the foam board to the pre-painted plastic containers. At this point I also stored the batteries in the mailer box and ran a cable to the Arduino below – this let me change the batteries while just being able to hot glue the plastic containers straight to the motherboard.
Hooking up glowing wires
Finally with the pack nearly complete I wrapped the electroluminescent wire around various parts on the motherboard and hose, securing them with cable ties for a realistic effect. The inverter boxes which you need to make the wire glow are also stored in the mailer box. At this point the mailer box was starting to come undone a bit with the weight of the batteries and from use so I taped some velcro onto the opening flaps.
The pack was great fun to make and it was really challenging trying to get everything to come together in time for the party. Playing with an Arduino again made me realise how much I’ve missed hacking with hardware and software together. The final step for the proton pack was to buy some Ghostbuster overalls from eBay and I was ready for the party!