UDATE: I've scaled back the project a little. It doesn't make sense to have an embedded NES system without a screen, so I'm leaving out the system and audio circuits, just doing an arcade style controller. Changed title to reflect this. Scroll down to my last post for updates.
UPDATE 5/14/2012: My controller is finished!
View more photos here:
I had to use a 555 timer in monostable (one shot) operation to prevent malfunction of games which poll the controller multiple times. It produces a single 5ms pulse to the counter chip which eliminates the multiple latch pulses in games like Super Mario Brothers 3. Toggling any button on and off with every latch pulse will freeze SMB 3 instantly! I learned that the hard way. I also eliminated the 7400 chips by using a couple of reverse-biased diodes to combine the turbo AA/BB with the A/B buttons to prevent shorting the counter output to ground when both buttons are pressed. I am also using a simple NPN transistor to act as a NOT gate to invert the latch signal prior to the 555. It also has a 4-speed rotary selector switch (3.75Hz, 7.5Hz, 15Hz on-on-off-off, and the absolute maximum achievable turbo rate of 30Hz on-off-on-off) and a slow toggle switch which connects to the START pin.
All in all, there are a total of three IC chips mounted on the solder-board:
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I would like to build a self-contained NES system shaped like a giant NES controller, with built-in top-loading clone NES system. It's an idea I've been entertaining for quite some time now. I've thought about doing SNES, but the button layout would likely be too complicated.
The entire unit will be self-contained except for the telivision/monitor which will be connected via an external coomposite hookup. Probably will be built out of Plywood, and feature real arcade controls with an output NES port for player 2 / Zapper use. I plan on cutting a cartridge slot into the top side for the cartridge, and bolting the clone system underneath the slot so that you just push the cart in through the top. I may line the hole with leather so that it doesn't abrase the carts. It will also have a built in amp and speaker with a full range driver.
Yobo or Hyperkin or Retrobit square top-loading NES clone (Say what you want about the quality of cloned hardware, but they are adequet for general purpose gaming, better compatability than most emulators, and I'm not butcherng a rare collectable top-loading NES, with inferior RF output I might add, for this project)
Plywood (I may also need to have them cut for me at the hardware store since I lack access to a table saw, and my circular saw is likely too inaccurate)
Sandpaper, Spraypaint, and adhesive vynyl sheets for controller overlay pattern.
Glue, screws, Power tools, Soldering Iron, etc. Basic stuff.
Perforated steel plate or screen to cover speaker hole.
Joystick (I'm assuming I need an 8-way joystick if I expect to use diagonals)
8 Arcade buttons, two red (A/B), four black (Start/Select/Turbo),
and two white buttons on the sides for pinball emulation (wired in paralell to Joystick Left and A buton)
Breadboard from Radio Shack
Power switches and a reset button.
4021N IC for the "brains" of the NES controller (no donors will be harmed)
At least 10 1K resistors for grounding the arcade circuits.
A 555 timer with an adjustable pot and an appropriate R/C ratio for turbo button control
LED indicators for power and turbo finction
Some simple logic gates for combining the output of the 555 timer with the turbo/A/B buttons. 74xx series logic chips should suffice.
RCA connectors for audio/video output from the back of the unit. I'll probably use a male/male adapterglued into the wall of the console. The clone system will have a short 1-foot RCA type cable connecting the composite video. RCA-3mm Stereo audio adapter for the Amp input.
A old 200-watt Shuttle PC power supply (the molex connector will supply 5V for the Clone and 12V for the Amp). Probably overkill for this project, but it's free. The Pwr-On pin on the motherboard power connector will be connected to the main power switch for turning on the system.
An old Cambridge Soundworks 5.1 surround system I have colecting dust. The analog pots on the sound system are all full of dust and have severe crackle issues, so it can no longer be used as a sound system. I will wire a new 10K pot to the outsite of the console for volume control, and run hookup wire which will solder to the old amp board. The sole output will be the center channel used as a mono sound source to drive a single full-range speaker. The other channels will remain unused. The sound output should be balanced provided both the left and right sound channel inputs are tied together. While the system originally ran on 15V, the supplied 12V should be adequet for audio playback at low volume levels.
Two full-range speaker drivers I salvaged a while back from an abandoned hi-def rear-projection TV which was discarded on curbside. I'll probably just use one of them as a mono sound source, or wire them in paralell for fuller sound.
Controller port #2 from the clone console for Player 2 / Zapper support.
The schematic for the NES controllers are well documented. I can build the analog turbo control from a carefully selected ratio of resistor/capacitor values in conjunction with a potentiometer. I'm looking for a range of about 2-20 Hz variable speed botton mashing, covering a much wider range than the NES Advantage. My college major is Electrical Engineering, so I know a lot about circuits.
My biggest potential isues, are what are the best arcade parts to use and where to get them for a reasonable price. Also what thickness plywood should I use? How big should I make the controller and still have everything fit inside? What is a good spacing for the A/B buttons? Also, the Arcade controlls are designed to be mounted on 3/4 inch plywood, wheras the switches and pots they sell at Radioshack are designed to be mounted on much thinner 1/16 inch thick project enclosures. Do i need to leave the back end open for ventalation, or install a low-RPM cooling fan? I don't expect the cabinet to pull a lot of wattage, but the components probably shouldn't be sealed off. I also may need to access the guts from time to time. A hinged bottom should do the trick.
Tips, advice appreciated.