LCD NES ZAPPER

demonofaj · Post by **demonofaj** » Fri Jul 29, 2005 7:35 pm

usbcds had the idea of putting the NES phaser into a pen. However Daguuy informed us that it wouldn't work. I have an idea though. Since the phaser reacts on a DOT of light. Maybe there could be something the light from the LCD could reflect on, providing the dot. Such as a screen portector. You guys think it could work.

soundwave · Post by **soundwave** » Fri Jul 29, 2005 8:18 pm

the gun doesnt work on LCDs.

usbcd36 · Post by **usbcd36** » Fri Jul 29, 2005 9:49 pm

By looking through the lens that is in the Zapper, I have found that it focuses to ONE dot of light anywhere. There has to be a way to mess with some circuitry in the gun to make it work. Even if it requires a complete redesign of the board, I shall try. I will need information on how the Zapper operates though. Maybe through this, I can mod the gun to work on an LCD.

vb_master · Post by **vb_master** » Sat Jul 30, 2005 7:09 am

Wikipedia wrote:When the trigger was pulled, the game blanked out the screen with a black background for one frame, then, for one additional frame, drew a solid white rectangle around the sprite you were supposed to be shooting at. The photodiode at the back of the Zapper would detect these changes in intensity and send a signal to the NES to indicate whether it was over a lit pixel or not. A drop followed by a spike in intensity signaled a hit. Multiple sprites were supported by flashing a solid white rectangle around each potential sprite, one per frame.

Wikipedia NES Zapper Page

Foxx373 · Post by **Foxx373** » Sat Jul 30, 2005 8:30 am

If i had a zapper, i could do some testing to see if this is possible. I dont see why it isnt. Like VB_Master said, the zappers Photodiode is just looking for light or dark, it should still work on an LCD. The only problem you might have is rebuilding the Zapper into a pen. The Zapper has a convex lens in it which will focus either light or dark onto a specific focal point at which the photodiode is placed. Why wouldnt this work on an LCD screen? Besides the fact that the focal point in the zapper was designed for at least a 15 inch tv from at least 4 feet away? If you redesign the focal point for a 5 inch LCD from a foot or so, it should still work. Well, it will work as long as the LCD has a good enough refresh rate...

demonofaj · Post by **demonofaj** » Sat Jul 30, 2005 11:32 am

It really seems plausible though.

usbcd36 · Post by **usbcd36** » Sat Jul 30, 2005 1:56 pm

The board for the Zapper could be built into the controller plug (to make the pen small) or even rebuilt. It is a fairly simple circuit involving a few resistors and capacitors, shouldn't be hard to remake on a long, thin PCB that will fit into a large pen-like instrument. The lens can be cut down too, it only has to focus in the center.

vb_master · Post by **vb_master** » Sun Jul 31, 2005 6:22 am

Perhaps this will reveal an answer.

Foxx373 · Post by **Foxx373** » Sun Jul 31, 2005 8:57 am

The Wikipedia entry really doesnt give any resoloution to this. Allthough it was quite intresting to read! I have the original schematic to the zapper. Its slightly more complex that a few resistors adn capactiors. It has an IR Preamplifirer (Sharp IR370TA) and a transistor (NPN C458) as well. But is still not too complex to build.

The convex lens can easyly be obtained from an old CD Rom drive, or Disc-Man CD player. I would try and get a better lens though. The smaller the lens, the less range you will have on the gun. You could use these to help calculate focal point and magnification size:

Focal Lenth in mm = 250 / (Magnification - 1)
Magnification = (250 / Focal Length) +

If someone can find a datasheet on the IR370T i can cross refrence it with a replacement chip. I see that there are some SOIC IR Preamps availabe. Im sure with one of those wou would be able to make a Pen-Zapper...

tom61 · Post by **tom61** » Mon Aug 01, 2005 3:19 pm

The gun is so extremely simple, it'd probably work just having the photo diode against the screen where you wanted to fire (i.e. the tip of the pin), without any additional optics.

BTW, you might want to change the title, as the GunCon and NES Zapper work quite a bit differently. A normal GunCon won't work on LCDs or 100Hz+ TVs (common in Europe).

kidw/32+systems · Post by **kidw/32+systems** » Tue Aug 02, 2005 9:15 am

the only thing i have to say is you would have to make it a pen b/c if your out in public w/ your NESp and you want to play duck hunt some old lady might think of some thing different (that would be funny to watch) and you get in a giant mess and every thing is messed up
eve if the pen is huge it would be a good idea

Cyberblade · Post by **Cyberblade** » Fri Aug 05, 2005 5:55 am

It won't work. It senses a change in intensity from the TV, the TV uses a light gun to display it's image, meaning such intensity can be detected, but an LCD doesn't. And LCD changes the colours of the individual pixels, not the light, so it's not possible for the light gun to work. No matter how much you modify it.

tom61 · Post by **tom61** » Sat Aug 06, 2005 9:31 pm

Cyberblade wrote:It won't work. It senses a change in intensity from the TV, the TV uses a light gun to display it's image, meaning such intensity can be detected, but an LCD doesn't. And LCD changes the colours of the individual pixels, not the light, so it's not possible for the light gun to work. No matter how much you modify it.

POINT THE ZAPPER AT A LIGHTBULB while playing, and see what happens. IT SENSES LIGHT, nothing more, nothing less. With other lightguns, you'd be right, but not the zapper.

Metroid fan · Post by **Metroid fan** » Sat Aug 06, 2005 10:55 pm

But even so whats the point then you could just aim it at the screen and shoot and no matter where you shot you would get a hit right?

tom61 · Post by **tom61** » Mon Aug 08, 2005 10:49 am

No, the NES blanks the display for a split second when you fire, then it draws a square where the target is, if there's more than one target, it draws each square one at a time.