Game Tin: Handheld Games With No Batteries

Anyone who grew up with a Game Boy knows how well they sucked through AA batteries. [Nick]’s Game Tin console solves this problem by running of an ultracapacitor charged by solar power.

The console is based on a EFM32 microcontroller: an ARM device designed for low power applications. The 128×128 pixel monochrome memory display provides low-fi graphics while maintaining low power consumption.

There’s two solar cells and a BQ25570 energy harvesting IC to charge the ultracap. This chip takes care of maximum power point tracking to get the most out of the solar cells. If it’s dark out, the device can be charged in about 30 seconds by connecting USB power.

The 10 F Maxwell ultracapacitor can run a game on the device for 1.5 hours without sunlight, and the device runs indefinitely in the sun. Thanks to the memory display, applications that have lower refresh rates will have much lower power consumption.

The Game Tin is open source, and is being developed using KiCad. You can grab all the EDA files from Bitbucket. [Nick] is also gauging interest in the Game Tin, and hopes to release it as a kit.

54 thoughts on “Game Tin: Handheld Games With No Batteries

        1. It depends on the range of games i guess. Current comercial portable game systems with large developers using their platform can charge hundreds of dollars and the hardware can hardly be that expensive. Maybe if you could access the Android store games or some steam games or something this would be a really desirable system. Indefinite play in the sunshine? Parents will love it!

  1. The original GameBoy had pretty good battery life at around 25-30 hours. No backlight helped with that though.

    The Game Gear however would destroy a set of 6 AAs in about 2 hours.

    1. An unmodified Sega Nomad did the same. That fluorescent display back light sucked up the battery life like no other. I’ve done the display mod for mine, but I have yet to do a true time test on a fresh set of batteries for it. I mainly did it for the improved display.

  2. Correct me if I am wrong

    C = q / U    [F] = [C] / [V]    capacitance
    q = I * t    [C] = [A] * [s]    charge
    q = 4 C
    I = 4/5400 = 740µA
    1 Ah = 3600 C
    q = 1.11 mAh
    

    That’s not too much compared to CR2032 or even smaller button cells. Is it possible that the whole circuit needs only 740µA?

      1. >Future posts will look at power consumed by the switch pull up resistors, more accurate loss calculations, and optimizations to reduce power consumption.

        BTW you can save power for the switch pull-up resistors. I assume that you are using some internal programmable pullups/pulldowns at the ARM GPIO. You only need to use pull up just before your polling the pins, but for the rest of the time change the pull-up into pull downs (or simply drive it low).

        Alternatively, if you are using the pin change interrupts, you could precharge the parasitic capacitance and let the pin float. (The capacitance would pull up the pins for 10-20 ms and the first falling edge/level can trigger an interrupt. YMMV for capacitance and leakages)

        I used that trick to detect SD Card presence, when the card pull up is 3x higher than my GPIO pulldown resistance. Should have read the specs, but it is a quick & dirty hack that works for me and the extremely dry weather here. https://hackaday.io/project/1347/log/9878-microsd–fatfs-in-dma

  3. The price is not that scary, sounds about right for what you get… true… at its launch the U.S. retail price of Game Boy Color was $79.95 however an orignal uncirculated (and thus rare) Gamboy in mint unused condition is currently being offered for $899 +P&P http://www.ebay.co.uk/itm/like/151439687723?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108&ff19=0 – it all rather depends who your marked is. I like where this Game Tin is going, ultra low power devices always brighten up my day, but sadly I would never use it, so I cant justify buying it.

    1. As ever with Ebay, the offer price is what some cheeky deluded dreamer thinks it’s worth. What it’s ACTUALLY worth is the end sale price. $20 if he’s lucky. Original Game Boys are dirt common, and consoles don’t inspire the love that old computers do. Except maybe the really rare ones. And the Gameboy’s box was just a bit of cardboard with a flimsy tiny manual, nothing to cherish.

      The market for old games changes a lot year by year anyway. Early 1980s stuff was desirable for a long time, when the kids of that age had grown into an age where they could spare the money, and were feeling nostalgic. Now a lot of that generation seem to have got bored of collecting. The best time to sell a Vectrex was a few years ago, things don’t just appreciate forever.

      1. You sir, dont know collectors…. A mont unopened GB fat un box really sells for 1000€… And rétro consoles get much more attention than retro computers… The market is larger, more accesdible . as for prices, check Neo-Geo or rare games, systems,révisons, and you’ll see…

  4. Is this display tech available in larger sizes and resolutions? I’d love a never charge ebook reader.

    A lot could be done to make this viable for mass production, like single pcb and flat build. Also much larger panels.

    This is a fantastic proof of concept. Also amazing that it fit in such a small tin. But I would have a lot of trouble holding and playing one.

    Even if you want to see it realized differently you have to give credit for his vision inspiring you.

    I’m just assuming that the supercap has theoretically infinite recharge cycles? If so it would be nice to see them used in more devices instead of lithium.

    1. There are larger sizes and resolutions in various low power technologies. You’ve identifed a big reason for doing this project which was to demonstrate what is possible now and give inspiration for what will be possible in the future as the technology improves. The capacitor being used is rated for 500,000 cycles. Thank you for your idea, and I’d be happy to hear others.

      1. There are people working on a calculator, using the EFM32 chip. Not released yet, but details of the wp43 are in the forums at hpmuseum.com
        Finding the right size screen, with low power requirements, is a pain. No wonder so many projects take short cuts: throw in wifi / bluetooth, and send data to a phone or tablet.

      2. It is very nice inspiration. Makes me wonder a lot of things
        What it’s like to have a device (beyond watch capabilities) that never ever needs charging or tending to.
        How much battery life we’d get out of retro consoles made with new hardware.
        How much battery life my phone would get using a front-lit LCD and a monochrome mode.

    2. Ebook readers use almost no power except when they’re actively doing stuff. Maybe just adding a solar panel to the back of an existing reader would do the trick. About the same size as the reader itself might work well. Plus all the battery and charging stuff is already in there.

    1. Outdoors in good sunlight it would take about 5 minutes to charge the completely discharged capacitor to 0.7V after which the boost converter could start and the electronics could be powered. Ideally you’d have some existing charge so you could use solar to sustain operation rather than starting completely discharged.

  5. Maybe someone can enlighten me why the capacitor is better than a plain rechargeable here?

    If you are charging limited by the USB power, why couldn’t a battery charge in the same way? The advantage that a battery will offer more energy in the same space.

    The whole project is awesome, but i think it would be better off with a plain old rechargeable.

    1. Charging time and possibly longevity.

      Ultra capacitors can be charged at many times the rate as batteries. Batteries are typically 1/10C though some quick lithium charges can do 1-5C. Over USB a supercap would be limited by the amperage of your USB port.
      Batteries have a couple thousand charge cycles in their life span if you treat them nice, ultra caps have tens of thousands of cycles.

      1. Actually you will get more than thousands of charges if you only charge/discharge a fraction of the full capacity. My point was that over the life of the device, a battery would probably be enough, more capacity will mean less charge cycles than a supercapacitor. More capacity means more life from a single charge.
        There is a big reason why no portable device uses supercapacitors, even abstracting the cost: they are less dense, for now. Nobody will want a phone that lasts 1/10 of a day, even if it would charge in 30 seconds for that lifetime. You would like a device that lasts as long as possible so that you don’t have to charge it 10 times per day.

      2. but the selling point of this is the solar battery. It is the limiting factor to the charging current, not the battery. IMHO, a CIR2032 (rechargeable LI-ion) coin cell is a far better choice. A battery has a nice flat discharge curve, so the toy can operate without a fancy power supply. You now have a low cost ultra low power/lighter/smaller model, one without the energy harvester chip, solar cells.
        Make a add-on power pack with the solar cell etc.

      1. Why not just use a LiPoly pack? The energy density is a lot higher, and it’s easy to configure the BQ25570 to charge it. I’m afraid you’re going to find that charging the battery/cap isn’t as easy as you think. I know this to be true, since for 2 years I’ve been building a product with the same solar panel and BQ25504.

  6. I’m still having some trouble understanding the engineering choice of a supercapacitor vs. a small LiPo. The product requirements: high energy density, low cost, low self-discharge rate all come down in favor of LiPo. The supercapacitor’s real benefits, power density and charge rate, are largely unnecessary here, and its self-discharge (leakage current, really) of 40uA means that with a full charge it’ll be dead in a week and below the usable 0.7V voltage in just over 5 days, neglecting other parasitic system consumption. The lifetime is nice, but the fact of the matter is that with a LiPo you’re unlikely to hit 1000 cycles even with daily use. Given that the effective capacity of the supercap is 9 mWH, even a 50 mAH LiPo would provide more than an order of magnitude more storage, be capable of being charged at the same rate (still far more than the solar cells can put out), and if you’re really worried about lifetime, just run it consistently between 60% and 80% SOC, which is still a longer play time than with the supercap.

    1. There were a few reasons for choosing an ultracapacitor. One of the reasons is the eco-concious vibe I was going for. The ultracapacitor has a long life supporting a long product lifecycle. The ultracapacitor also doesn’t have chemicals that are as hard on the environment as chemicals in batteries. The project is meant to be a little forward looking. I agree that a battery has some advantages as you mentioned, but ultimately I wanted to see what I could do with an ultracapacitor.

      1. When you are charging it at well below 1C rate, which would be the case here, the life cycle of LiPoly is very long. It’s just something to think about: the e-waste of the Lithium battery isn’t really much worse than that of an ultra-cap.

          1. So to continue with the 50mAH cell scenario, assume the maximum charge rate is 1C. That means you’re charging the cell at 50mA (give or take), or roughly 185mW. Now let’s say you want to transfer 9mWH of charge, the full amount that the supercap can take. In the supercap’s case you’re charging at 2.5W. The charge takes 13 seconds. In the LiPo case you’re charging at 185mW. The charge takes 3 minutes. Neither one is particularly onerous in my book. I do appreciate that you want to see what you can do with an ultracapacitor. That is, after all, why we’re all here…to learn and develop our interests.

  7. Hi Nick, I tried contacting you via the game tin website but the form was not working and requested a username/password. I work for Silicon Labs and have been following your project – very interesting and I’m excited to see you using EFM32. Would you mind sharing your contact info?

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