Tuesday, 16 December 2014

Space, how low can you go...

I really should be doing other things, but tonight I tagged this up. This Nerf Jolt is now a very basic but functional Lasertag gun.

I've been asked to make a pair of concealable 'assassin weapons' for a game and although I don't have the actual gun board yet I wanted to mock it up with what I have because I'm impatient.
I ripped all the Nerf internals out, including using a drill to destroy the one-way valve mechanism at the back of the barrel. Then I fed this lot in.

I've got a TSAL6100 IR emitting LED, 5mm white LED, small piezo sounder, Arduino Pro mini and a small LiPo battery squeezed in.

I'm actually using a 5V Arduino Pro mini at 3.7v but it seems to work fine. I've got a 3.3V version on order, but like I said I was impatient.

With a very basic sketch loaded up it lights up the muzzle flash LED, makes some white noise then emits a simple tag hit with IR.

What it lacks at the moment due to lack of space is an on/off switch, charging jack and reload button. It just fires repeatedly and you have to take the bottom cover off to disconnect or charge the battery.

For what this is intended for these limitations aren't huge. It's aimed at a four hour indoor LARP where it'll be hidden on somebody and maybe not even used. I could go with a smaller LiPo and then maybe be able to fit an on/off switch, again I just had this one kicking around.

What I definitely need to do though is stick the IR emitter in a piece of tubing to constrain the output. Right now it hits everything in front of you, and I mean everything. Reflection isn't noticeable indoors, I've put a fair size resistor on the emitter and it's driving straight from the Arduino so quite current limited.

Sunday, 14 December 2014

Spookytron 2 first testing

A very long time ago, my first ever Arduino project was Spookytron, which in a fairly dumb way played spooky noises for use in LARPs.

PIRs detected motion and it played sound somewhere else. If you walked towards the sound it stopped.

Very simple stuff but it was my first project and it was surprisingly effective.

The big problem is it was housed in one central box and had speakers on the end of very long cables. For convenience I used CAT5 cable as it's something that's easy to buy pre-terminated and I had a load anyway.

It got used twice but the need to lay massively long cables round a wood got tiresome very quickly. As soon as it got used people said, 'can you do a wireless version'.

When I saw Ciseco's SRF radio technology it was obvious this was a good use for it. I've been busy with other things, but now I'm having a first stab at it.

Here we have a very simple mesh of two nodes. Mesh discovery isn't in place yet and it's got one sound PCM encoded into the sketch but if you trigger one device, the other plays the sound. I've used Ciseco's LLAP protocol for this which is trivially easy to work with, it's just fixed length serial human readable messages with a two character address field.

The plan is to do this with some RFu328s which will be much smaller but right now I'm prototyping it with a couple of Unos and the shields from the Kickstarter.

The LLAP library Ciseco released needs a ton of work, so I'll hunt the Internet to see if anybody has done a better one. I seem to remember spotting one a while back.

Going in circles

Paintball exists so that people can play at shooting each other without using real guns. Somebody released a video game where you play at pretending to shoot each other from the comfort of your front room.

Now I've been gifted these two paintball style light guns from that game and plan to convert them to Lasertag so we can use them to run around in the woods pretending to shoot each other. With a pretend version of a pretend gun.

All very circular.

They are really cool looking though and without the paintball reservoirs on top make an excellent base for some scifi blaster pistol style guns. As with a lot of these light guns there are a plethora of switches set up nicely and the original light sensor assembly will probably make a good base for a Lasertag emitter. Because this was some kind of standalone game they even have a battery holder in the grip, which I may re-use if there's plenty of space elsewhere in the body.

Apparently the 'slide' on top shoots back when you fire, but I suspect that will be a casualty of having to fit a Lasertag circuit, sound board, speaker etc.

Tuesday, 2 December 2014

Making Magic Wands

I've made a few prop magic wands and a friend asked if I could write up  the process. You don't need much apart from a hot glue gun, dowel and paint.

Start with a 30cm/12" piece of 8-9mm dowel.
Put a point on one end and some texturing on about half of it. I used a dremel, but a rasp, file or in a pinch sandpaper will do the job.
Next, use a hot glue gun to build up some organic looking lumpy bits to mark the ends of the handle section. You will want to do this in a couple of goes, allowing it to mostly cool in-between. If you try and build it up too quickly it will just run too much.

The glue tends to try and run off so use a low setting on the glue gun or keep turning the dowel.
Once you've got a kind of hilt and pommel, let it set for a good half an hour or so. A big accumulation of hot glue like this can take a while to cool completely.
Next, paint the glue with some standard acrylic paint in some kind of accent colour. This helps the woodstain we'll use next to stick to the glue, it tends to run off without. Also, it provides some shading so feel free to mess around dabbing it on. I've not found straight lines and geometric patterns to work very well.
Once the acrylic is well dried, use some external woodstain to cover the bulk of the wand, holding it by the tip.
Once that half is dry do the other half. This wand is quite dark, deliberately. You often get better shading with a lighter stain.
Finally I used some glue to add a little glitter at the tip. You wouldn't want to do this with every one, but this felt like it needed brightening up.
Using this method you can make a few variations on the theme so each wand is unique. I did 25 for a LARP once and had a little production line going.