A must-have peripheral for games consoles of the 1980s and 1990s was the light gun. A lens and photo cell mounted in a gun-like plastic case, the console could calculate where on the screen it was pointing when its trigger was pressed by flashing the screen white and sensing the timing at which the on-screen flying spot triggered the photo cell.
Unfortunately light gun games hail from the era of CRT TVs, they do not work with modern LCDs as my colleague [Will Sweatman] eloquently illustrated late last year. Whereas a CRT displayed the dot on its screen in perfect synchronization with the console output, an LCD captures a whole frame, processes it and displays it in one go. All timing is lost, and the console can no longer sense position.
[Charlie] has attacked this problem with some more recent technology and a bit of lateral thinking, and has successfully brought light gun games back to life. He senses where the gun is pointing using a Wiimote with its sensor bar on top of the TV through a Raspberry Pi, and feeds the positional information to an Arduino. He then takes the video signal from the console and strips out its sync pulses which also go to the Arduino. Knowing both position and timing, the Arduino can then flash a white LED stuck to the end of the light gun barrel at the exact moment that part of the CRT would have been lit up, and as far as the game is concerned it has received the input it is expecting.
He explains the timing problem and his solution in the video below the break. He then shows us gameplay on a wide variety of consoles from the era using the device. More information and his code can be found on his GitHub repository.
Continue reading “Tricking Duck Hunt To See A Modern LCD TV As CRT”
Still, the housing has seen some careful design and attention to detail in its construction. He started with a 3D CAD model from which he created a set of 2D templates to print on paper and from which to cut the wood. As many of his dimensions as possible were taken from common wood stock to save machining time, and the structure was assembled using wood glue before being sanded and filled. Finally, the intricate parts such as the Pokémon logo were 3D printed, and spray painted. The result is a pretty good real-world replica of the Pokémon Center that you’d recognise if you were a player of the original games, and he reports it was a hit with gamers in his local park.
