[Chris Downing] recently finished up a major project that spanned some two years and used nearly every skill he possessed. The result? A smart air hockey table with retro-gaming roots. Does it play DOOM? It sure (kind of) does!
Two of the most striking features are the score board (with LCD screen and sound) and the play surface which is densely-populated with RGB LED lighting and capable of some pretty neat tricks. Together, they combine to deliver a few different modes of play, including a DOOM mode.
The first play mode is straight air hockey with automated score tracking and the usual horns and buzzers celebrating goals. The LED array within the table lights up to create the appearance and patterns of a typical hockey rink.
DOOM hockey mode casts one player as Demons and the other as the Doom Slayer, and the LED array comes to life to create a play surface of flickering flames. Screams indicate goals (either Demon screams or Slayer screams, depending on who scores!)
Since the whole thing is driven by a Raspberry Pi, the table is given a bit of gaming flexibility with Emulation Mode. This mode allows playing emulated retro games on the scoreboard screen, and as a super neat feature, the screen display is mirrored on the tabletop’s LED array. [Chris] asserts that the effect is imperfect, but to us it looks at least as legible as DOOM on 7-segment displays.
This project is a great example of how complex things can get when one combines so many different types of materials and fabrication methods into a single whole. The blog post has a lot of great photos and details, but check out the video (embedded below) for a demonstration of everything in action.
I would be neat to see this but also tracking the puck and displaying a “trail” of the puck like the Glow puck that Fox super imposed back in the day in hockey broadcasts. I have no idea how to do that but I’d like to see it!
We kind of thought about that. The simplest way would have been to use a camera to track the pucks position, but because the score board was only about a foot off the table, we couldn’t get a wide enough view to track it properly.
So a wide-angle lens would fix that. You might try a stick-on lens for cell phones.
However, camera-based tracking would have latency. Some kind of optical sensors on the table itself would reduce that. One possibility is a set of light beams crossing horizontally and vertically over to optical sensors on the other side. Another is an array of IR emitters/detectors that can tell if something is above them on the table.
Continuing to brainstorm, you could potentially also use a 2D lateral effect photodiode in place of a camera above the table. If the LEDs on the table are strobed one at a time, the photodiode will instantly provide a X/Y reading of which one it sees (or not, if blocked by the puck).
Yeah, my main concern with anything light sensitive or optical (aside from a top down camera) is the fact they’ll be sitting right in a sea of flashing LEDs. I worried about this with the puck trap sensors and the LED’s actually flash through the acrylic table top and spacer, right into the traps themselves. Luckily it didn’t cause a problem in that case, but I did have to switch to a totally opaque puck for it to work properly.
Hey guys, it’s Downing, one of the creators of this table. Serious question. If there was to be a table 2.0, aside from the puck tracking which seems to be a favorite, what other cool features do you think would put this over the top?
Maybe a “black out” section. Something where if the puck hits the area lit in red then automatic “goal”