Battery-free Game Boy runs forever | Hacker News Reader

Battery-free Game Boy runs forever

techxplore.com

24 pointslelf16 comments

> Most importantly, it impersonates the Game Boy processor. Although this solution requires a lot of computational power, and therefore energy, it allows any popular retro game to be played straight from its original cartridge.

It's not clear whether they're emulating the Game Boy in software and this is just running on an ARM or something, or if this is an FPGA-based hardware recreation (or even custom silicon, since schools can have the resources), or if they actually harvested the hardware from an old Game Boy. Aside from the custom silicon, none of these would be maximally energy efficient (the real GB would've been done on ancient processes), so it's exciting to think about what a battery-less gaming system could be if the market demanded it.

it is a low power arm chip emulating the eZ80 in the gameboy no audio is emulated (or played).

it is the hardest to emulate right, and audio playback needs a lot of power

You could get pretty close by doing a static recompilation of Gameboy Z80 software (ala https://andrewkelley.me/post/jamulator.html) to target an ESP32-based system.

Oddly enough there was a Gameboy game in Japan with a sensor on the cart that required sunlight to play. The intent was to get kids to be outside more. Guess they didn't think about a standard desk lamp.

Boktai (which did get released outside Japan): https://en.wikipedia.org/wiki/Boktai:_The_Sun_Is_in_Your_Han...

Standard desk lamps wouldn't work for Boktai, but a UV light always maxed out the meter. Kids are way less likely to have one of those lying around.

What kind of UV lamp? Sounds like it could potentially be dangerous to cheat.

Well, seeing as it was attached to a keychain...

What kind of sunscreen are you using right now, by the way? Sounds like it could potentially be dangerous to go outside.

Someone could buy a UV-B Lamp off ebay and do some serious damage.

To do their in-game enemies mostly.

Why did they put the solar panels on the front? I personally prevent sunlight from reaching the screen due to the annoying reflection, putting it on the top and back seems a better option.

I found it ingenious that they used the console's own buttons as an additional source of power (I don't know of any console that does the same)

Probably because it can barely power itself as it is - it sounds like it needs to stop for a second every 10 seconds so it can harvest power.

If this is true then the save of the installed cartridge is in danger. Gameboy cartridges are saved in volatile SRAM that run off of watch batteries when unplugged from the console. When plugged into the console the SRAM is supplied power by the console. If you had a watch battery die while plugged into this perpetual gameboy you would never be able to save the game. You’d have to leave the cartridge plugged into the gameboy to keep the state.

The lag is due to it dumping state before it switches power sources, then reloads.

Reminds me of Playdate [https://play.date/], a handheld game device, that had a crank on the side. Unfortunately, I don't think you could charge the batteries by winding the crank.

"Forever" so long as solar and kinetic inputs are effective.

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