Kim has been a fan of Doctor Who for as long as I can remember, but she helped get me into it a few years ago and now we’re to the point where we watched the last 3 seasons episode-by-episode as soon as they aired (thanks, p2p filesharing!). Well, for her birthday this year, I built her a TARDIS! Not like the last one, either.
This TARDIS is made from clear acrylic of various sizes and cuts and painted with “Phthalocyanine Blue” acrylic paint (which gives a decent approximation of a wood texture up close). There was lots of hand routing, drilling, cutting, and fast-paced handiwork involved! I mean, I originally put most of it together over the course of the 5 days preceding her birthday back at the beginning of June 2011, and then I had a few more days of apologetic finishing to do the following week. We ended up taking it to A-Kon 22 and carried it around the con, where we got lots of compliments; it was a lot of fun! This past week, I rebuilt the electronics to hide everything at the top and make some modifications to the way it all functioned.
On the details side, it was a lot of work. I even had to force myself to get into Arduino programming. Well, kinda “forced”. I’ve done some work with PIC microcontrollers in the past, but I had been in this sort of “analog phase” (well, obsession) for the past few years so I had an annoying anti-new-stuff attitude going on that I feel a need to apologize for. I saw the Arduino platform as too simple for me and I still do think that a lot of it has been wayyy over-simplified; people who don’t even know how to solder are able to put together complex controlling systems that others have programmed. I also saw it as kinda pricey until you realize what you are doing (I started out with a ~$19 Arduino Pro Mini and a ~$15 FTDI Basic Breakout Board), but now I know that all I really need for any project is a ~$4 ATMEGA 328P IC and some other cheap components to build a project around.
I built the sound system system with LadyAda’s Wave Shield design and code; it was pretty much throwing some components together and getting it all to work pretty much right away. I needed something quick, and I surprised myself by having a working perfboard soldered together the day after I received the components I ordered from Sparkfun and Mouser.
There is a reed switch and a magnet on the right side door that triggers an internal 1W RGB light (100% red, 50% green; kind of a gold-orange in person) and door opening/closing sounds appropriately. The lantern light is a 3W warm white LED, and the interior light is a second 1W RGB LED; when sounds are playing, an LM324 (best op-amp for single-supply low-voltage circuits) is setup with an active low-pass filter and envelope follower and 2n3904 driver for the interior light (it basically stays on the entire time something is playing) and an active high-pass and 4x parallel 2n3904 driver to handle the 900mA for the lantern LED! I have to wait until I have some more spending money to order some wide-angle white LEDs for the “police box” signs, but I have some blue LEDs that are working nicely for now.
There are 12 buttons hidden on the bottom twelve panels of the sides and back; each one triggers a different sound stored on an internal SD card. There is an external 16V input for charging the 5x 2400mAh NI-MH batteries powering the whole thing, a switch for turning the “police box” sign lights on and off, and another switch for turning on the sound and lights system. With both switches off, no power is consumed and the TARDIS can sit for months without needing to be charged thanks to the Powerex Imedion batteries which are charged with a simple LM317 constant current source that trickle charges at 90mA.
The door is lockable via a turnable screw head through the door and another screw bolt soldered to the other end that rotates parallel to the back of the door, locking into a piece of metal that prevents the doors form opening when “locked”. It works nicely, and Kim likes how a screwdriver is needed to open the door.
Kim loves her new TARDIS, and I had a lot of fun building it for her! I love you, Kimberly! :D