Serial to USB SMT Dual Layer Design:
Attempting to breadboard the circuit was a difficult process, only having 3 of the USB chips I decided to give it only one try. I would need the other two for the board.
I managed to get all but one of the connections onto wires so I could breadboard the chip, but one missing pin will cause the circuit to not work. Below is a picture of the attempt:
Look at that spider!
The PCB:
After all that work trying to get wires onto the pins, I decided to go with the PCB board approach. Paul Boese already completed a board layout which he claims works, so I decided to change some
small details and make the board off of his design. Surface mount technology can be a difficult task, but it can also be simple, you need to have a steady hand and a narrow iron tip, lightly soldering the pins
while you press the IC to the board helps the pins mold nicely to their corresponding pads. The problem with suface mount technology is that at my college we use mostly discrete non SMT components and DIP style IC's.
This makes it easy for the breadboarding process, but difficult for making smaller boards. I had to wait on several online companies like Mouser and Digi-key to recieve all my parts, some of them which had
to be backordered. Components that were still on their way had to be replaced with larger non SMT ones from the lab. This makes an uglier board, but due to my time constraints it was necessary.
Making a dual layer board consisted of masking a two sided copper plated board and using chemicals to wear away at the unmasked portions of the surface. It needed to be aligned correctly so that pads connecting the bottom
to the top would be close enough to drill a whole and fill it with a conductor (small wire and solder). After completing the board, unfortuanately I noticed inconsistancies with the schematic, I remedied all of the problems I
could find with wire jumper solutions. Below you can see the dual layered SMT board that has been modified to look like a rat's nest.
On the left side we see the Dreamcast serial cable and on the right we see the activation LED and the USB female type B connector. The difficulty of wiring the jumpers was close to the previous attempt to make a breadboarded circuit.