Step 1 : In the beginning....

This controller is a modified version of the 300 channel controller that Hill has designed. Although it's only 16 channels, it will resopond as any 2 of the 40 boxes as in Hill's design. The only restriction is that both boxes have to be on the same bank. You just set some jumpers and presto. This is great if you just want to make a few at a time because they can all read the same printer port.
I needed a smaller unit to use on a special project (see the America Flag pictures in the Photos section). The added benifit of this design is that it's small enough to fit just about anywhere, yet it has all the features of Hill's original design. Also it's great if you're on a tight budget. If you don't need 300 channels, you can build just a few of these to meet your needs and make more later if you need to.

Step 2 : Finding the schematic

Email me if you would like a copy of the current schematic. To see the "alpha" version of the schematic on line, it can be found in the forum. Look under Light control. Scroll to the bottom and click on where it says "Older Messages". You'll have to go way back to April of '02. You're looking for a message entitled "New port controller design". The schematic is too large to put here. Remember... that schematic is my original concept schematic. This controller uses basicaly the same design, just a bunch of wiring changes.

Step 3 : Making the PCB


I chose to have the printed circuit boards made professionally. Because of the size of the board, some of the traces were very small and a double sided design was nessassary. I chose to use a service called ExpressPCB (see expresspcb.com). They have a software package you download, you design your board, and upload your design back to them with your credit card info. Their cheapest option is their MiniBoard service. You can get 3ea 3.8 x 2.5 inch boards for $62. This includes thru hole plating, tin flow plating and 2 day shipping. What I did was to actually design a plug-in type board small enough to fit two on each PCB. I sent them my design, and then just cut the boards in half and presto! 6 boards for the price of 3!! Here's a picture of the board design. If you want to build this board, email me and I will send you the ExpressPCB board file so you can order your own. I also have a 32 port version that you can see if you look in the photos section.

Step 4 : Cut the Boards


As you can see here I have already cut the boards in half. I flipped one over so you can see the trace pattern on the back side.

Step 5 : Prepare to mount....


The board construction is pretty straight forward. Mount headers and sockets first.....

(Notice I'm using sockets with built in decoupling capacitors for the digital ICs)