How To Communicate With An Alien Artifact or . . .

Step 3 The Controller Board

For the controller circuitry you will need :-

• PicAxe 08M microcontroller and 8 pin DIL socket.
• 3 x NPN high gain transistors. I used BCX38C darlingtons. (Others will work but check pinouts.)
• 4 x 47K 1/8W or 1/4 resistors (yellow, violet, orange).
• 1 x 10K resistor (brown, black, orange).
• 1 x 22K resistor (red, red, orange).
• 1 x 0.1 microfarad 16V capacitor.
• 2 x miniature reed switches.
• Flat 3 x AAA battery holder.
• Sub-miniature piezo sounder. I reclaimed this one from an old PC motherboard. It gave a better sound than the larger bought ones, possibly because of its lower impedance.
• SIL header if you're programming the chip in-circuit.

This is a very simple circuit but made slightly more difficult because it has to fit into a small space.
The photos show component placement and track break locations. Be especially careful of positioning the wire links which join the various power strips. Place the battery connector and the two boards in place in the tin so you can judge what length to make the connecting leads. The three driver connections to the LED array board can be in any sequence.
^{(The first photo was taken from a slight angle and the tracks and IC pins don't appear to line up. I'll re-do this when I have a chance.)}

I've used reed switches as I liked the idea of not having any push-buttons on the case; Activating something using a magnetic field is much more tecchy! One of the reeds switches the power and the other is an input to the chip which is polled to alter the program flow. I'll definitely be using the magnetic switching idea on other projects.

Once everything is connected up, apply insulating tape to the inside of the tin, just to prevent those nasty little short circuits which can turn your electronic wonder into a piece of junk. Locate the boards and tack down with a few dollops of hot glue. This has the advantage of being secure, but you can lever it off if you really need to take the boards out.

Comments

[devilmaycry]

The project is totally cool but It would be realy helpful if you breifely explain how to make the controller because the picture s do not explain that much so .Thanks

[AndyGadget]

 
I beg to differ.  It's probably not the ideal project for an absolute raw beginner, but the first picture in step 3 clearly shows the topside component and link positions, the second picture shows the copper side cut tracks, and the PDF at the end of the step gives the circuit diagram.  Those three items make the project a simple build.