Monday, 16 September 2013

Safety first

With the time machine I'm making a pretty fiddly complicated prop with loads of stuff to go wrong.

I'm being really careful wiring it all up and sealing it in place so that things can't come loose or get snagged easily.

However there's a real possibility that it will go wrong and die or just malfunction badly. Equally the batteries may simply not last as long as I'd like.

So I've built in a connector for an external 12V PSU and a 'safe mode' switch. Flick it one way and everything is powered up via the Arduino and driven by the controls/sensors. Flick it the other way and it just supplies power to the plasma globe and under desk lighting using the dumb controller the LED strips came with.

This is already working so if I can't make the progress I would like over the next few weeks we'll have a prop that does something.


Friday, 13 September 2013

Time machine teaser #3

I plan to have a load of dials along the back of the machine, which will be built using servos and a bit of fakery.

Servos are easy to control and cheap as chips. Building a set of dials around them might take a while but will make it more unusual looking than a set of obviously modern moving coil meters.

I've got one vintage ammeter but they're pricey and obviously a 'set' is harder to come by.

Here I've quickly mocked up one dial so I can see how it looks. The 'hand' will most likely have a fine wire pointer on the final version and I'll make more effort with the face.

Tuesday, 10 September 2013

Pot handles

Having used a bunch of door handles as some of the time machine controls I need a way to read them.

So the obvious answer is mate the square shaft that you ordinarily use with a potentiometer.

I cut the shafts in half and did a bit of very rough and ready drilling so they go straight on the splines of the pot. This was a slightly loose fit so I used a little glue.

Now with these done and mounted I've wired up all the inputs on the top of the desk, apart from the touch switches. Which are very much optional.

Tomorrow I'll connect this all up to the prototyping shield. Ideally I'd like to solder it, but right now I'm going to leave the leads long and just poke them in the headers. It'll be a little flaky but at least allow me to try things out.

At the moment I have about twenty inputs to work with, there are a few more to come including a foot treadle, the handle we bought in Paris and if I can find somewhere to mount them some ultrasonic distance sounders.

Outputs are a little more sparse at the moment, right now the only thing ready to connect up is the vintage ammeter which you can see in the middle of the top.


Friday, 6 September 2013

Time machine teaser #2

Having done a couple more coats of the varnish I'm pretty happy that the finish on the top now looks as intended. So I've screwed the various bits I've got back onto it.

It's not all brass.

Thursday, 5 September 2013

Time machine teaser #1

For a LARP we're doing later this year I'm making a 'time machine' of the Victorian inventor variety. There will be brass, lots of brass.

The base for this is a £10 Laiva desk from IKEA, which we've screwed lots of brass stuff to and made various holes in. Now the layout is pretty much finalised I'm going to paint it up a bit so it's mahogany coloured. Here it is with the first couple of coats on.

Very soon I will start connecting all the stuff up to an Arduino I've bought for this job. There will be many buttons and knobs connected then various flashing lights and moving bits so it 'does stuff' in response. If things work out it should make the TARDIS noise and have a homage to the Flux Capacitor in the top right.

Ideally I should have used a nice piece of Victorian furniture for this, but I don't want to ruin something. Also if I mess up a Laiva I can just go and buy another one.

Tuesday, 3 September 2013

Hurrah for China

Yesterday I ordered an RFID reader/writer. I don't know what I'm going to do with it but it feels like the sort of thing I could have fun with.

It's implemented as a serial device that you send commands to so pretty generic and can be connected with all manner of things including a PC if you feel like it.

This was after wading through the eBay shop of a Chinese supplier with lots of little interesting bits and pieces. There is a lot of really cheap <£5 tat on eBay from these sellers but if you go up in price a bit it looks like there is some really nice kit available.

I was away at a Laser-Tag LARP over the weekend and I loaned them Spookytron for the event. It got used to make a 'haunted house' at the site and worked really well for this. Mik had a few suggestions for improvements which I'll feed into another version of it, but this won't happen for a while.

Right now I've a time machine to build.