Project Background:
My homie, DJ Diversify, asked me to check out an LSDJMC2 he was planning to buy on Ebay. The one he was looking at was built with a pre-perforated PCB, and had a rat’s nest of wires soldered onto it. It was enclosed by a hand painted case with mis-aligned buttons. The current bid was like $180. I told him it was garbage, and that I would build a better one.
Project Details:
I took Firestarter’s schematic of the LSDJMC2 and entered it into PADS Power Logic (schematic capture program). I made a prototype of the circuit on a solder-less student board just to make sure it worked. Everything worked as he said it would.
After spending some time on the schematic, I dug around the web a bit looking for an enclosure. I found the blue and red cases. I bought of few of each color to check them out. They were like $10 each, and shipping was another $10. The cases ended up being clear enough to see through, so I decided to put all of the front panel text on the PCB.
Now that I had the enclosure, I nerded out the dimensions of the PCB and how it was going to be mounted in the enclosure. The PCB was designed with panel mount push buttons so that they could be used to mount the circuit board to the front panel of the enclosure. This design eliminated the need for a front panel overlay, and also eliminated the need for PCB standoff’s and mounting screws. I’m lazy, so I didn’t want to spend a bunch of time building these things. With this design, all I would need to do is drill holes for the push buttons, the connectors, and the Gameboy link cables. After getting the dimensions worked out, I laid out the PCB using PADS PowerPCB. I had 30 PCBs manufactured (white with black silk screen), which I think cost just over $500 at the time. I did all of the soldering by hand to keep the cost down. I used sockets for critical components (like the micro-controller).
I needed to drill holes in the enclosure for the push buttons. I made a drill template using AutoCAD. This was easy cause dxf files can be exported from PADS to be used in AutoCAD. I was too lazy to make a metal template for a drilling guide, so I just printed the drill locations onto paper. I taped the paper template to the front panel of the enclosure. I marked the center points of the drill locations on the front panel plastic by taking a sharp center tap and mashing it into the paper template at the drill locations. This left a nice indention in the plastic. The paper template was then removed and the holes were drilled using the indention marks.
Firestarter was kind enough to give out his micro-controller (PIC) code for the LSDJMC2. I don’t write much Assembly, so his hex format code was plenty for me. I already had a PIC programmer, so no cost was added there. I think you can get the hockey puck IDE programmer for like $200 on Digikey if you need it. Finding the PIC chips is probably a bit harder. I bought and programmed 30 PIC’s.
I jammed the programmed PICs into the already soldered sockets on the PCBs. After that, installing the PCBs into the enclosure was as easy as tightening a few nuts for the panel mount push buttons.
These were going to be used for live performance and in the studio, so I ended up using wall power instead of a battery solution. I got a bunch of 7 volt power supplies from Halted in Santa Clara, CA. They were like $5 each, which is super cheap. I cut the end off of the supplies and added a new connector. The size of the new connector is very common, so it fits a readily available panel mount DC connector.
They turned out looking really clean and they are rock solid for live performance.