First off, let me tell you that if you want that kind of circuitry, you're probably going to be limited to the Eleventh Doctor's model
, or the one the Doctor will end up giving to River Song
. None of the older models are big enough to hold all that, lest you go with extremely expensive, tiny parts and multi-layer PCBs (or ASICs
For both the glass-shattering sound and the laser, you're almost certainly going to need a higher voltage than any common rechargeable AA battery would give you. Unless you want to go with a special type of battery, that means you'll need on on-board boost converter
. That means you can get a higher voltage, at the cost of more current. Supposing you want 8 volts at 350 mA to drive either the speaker or the laser, you're going to be pulling some 2.5 A from the battery, even with a high-efficiency switched-mode boost converter - around an hour of continuous use with a fully charged modern NiMH battery. Not much, but maybe just enough.
Now, the sound generation is a difficult one. I'm going to assume you want the classic whirring sound as well. If that is the case, you pretty much only have one option, and that is to use a microcontroller
. You can store the whirring sound digitally; preferably in an uncompressed, directly usable format (i.e. PCM samples). If your sound sample is encoded as 16 bits, 22050 Hz PCM samples, and is at most a few seconds long, you can easily store it on a simple (read: cheap) SPI
or I²C EEPROM
chip (1 Mbit is good for up to 2.8 seconds at the aforementioned sampling rate and resolution). I'd recommend a separate PCM
IC, because it's nigh impossible to get any appreciable sound quality without one.
The glass-shattering sound is ideally a custom-generated sine wave
. This is easy enough to generate with a microcontroller; use a lookup table with samples of a sine wave, and pick the next value from the table when a timer triggers; then pass that value to the external PCM. A potentiometer
attached to the microcontroller's analogue-to-digital converter determines the frequency. Based on the value of that potentiometer, you can calculate the time you need to delay before picking the next value from the lookup table.
As for the laser, laser diode modules aren't too expensive (I'd recommend DealExtreme
for them). You'll probably need a constant-current driver
; they aren't difficult to build, and usually require only a single transistor, a high-power resistor, and a few diodes.
Finally, it's important to note that you will have to learn how to solder extremely tiny surface mount
parts. There is simply no way you're going to get everything into such a small device with through-hole components, and having the board made by a professional shop would cost a fortune.
P.S. Arduinos aren't nearly small enough to do this nicely, unless you use a custom-built one, which is overkill in terms of its general-purpose capabilities, but still lacks the specific parts needed for this, such as the PCM and higher-voltage power supply.