Kodak DC20 Digital Camera Controller

Construction

DC20 Controller
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The controller was built on a PC board from Radio Shack. Radio Shack sells several sizes/configurations of pre-drilled, pre-etched circuit boards that are well suited for this sort of project. The copper traces make connections similar to those found on a bread board. The board I used is Radio Shack Cat. No. 276-150. A custom PC board can be printed and etched if you have the facilities for doing so, but for one-off projects, these general purpose boards make life a lot simpler.

Using a general purpose board like this means you will need to wire some connections with jumpers. I tried to arrange the components to minimize the number of jumpers, but I wasn't able to eliminate them all.

The eight DIP switches are connected to ground by soldering a length of uninsulated hook-up wire to the back side of the board. It's not pretty but it works. If you use this technique, make sure you test each connection for continuity.

A low-profile DIP socket was used for the IC. This allows the chip to be removed from the board for re-programming if the need should arise. Also, since the board is hand-soldered, the socket prevents doing heat damage to the chip.

The ceramic resonator should be located as close to the chip as possible. The two oscillator pins on the chip are adjacent to each other, but unfortunately the two leads on the resonator that need to be connected to them are not. Therefore, it is necessary to connect one lead of the resonator to the chip by way of a hook-up jumper.

The voltage regulator used here is rated at 1 Amp and has an appropriately sized heat sink. This is total over-kill. A low power version of the regulator (part number 78L05) is more than adequate. It is much smaller, yet still sufficient to power this circuit. I used the 1 Amp regulator since I had one in my parts drawer. I decided to bend the leads at a 90° angle and lay the part flat on the circuit board to prevent it from being bent around during handling.

A 9 Volt battery clip is connected to the voltage regulator, and hangs off the right edge of the board. A stereo mini headphone plug is connected to the 22KΩ resistor and jumper in the upper left corner of the board.