Handheld Game Console Puts Processing Power In The Cartridge

With the proliferation of cheap screens for use with microcontrollers, we’ve seen a matching proliferation in small handheld gaming projects. Pick your favourite chip, grab a screen off the usual suspects, add some buttons and you’re ready to go. [bobricius] has put a unique spin on this, with an unconventional cartridge-based build.

The main body of the handheld is constructed from attractive black and gold PCBs, and features a screen, some controls and an on/off switch. There’s also a microSD socket is on the board, which interfaces with cartridges which carry the microcontroller. Change the cart, and you can change the game.

[bobricius] has developed carts for a variety of common microcontroller platforms, from the Attiny85 to the venerable ATmega328. As the microSD slot is doing little more then sharing pins for the screen and controls, it’s possible to hook up almost any platform to the handheld. There’s even a design for a Raspberry Pi cart, just for fun.

It’s an entertaining take on the microcontroller handheld concept, and we can’t wait to see where it goes next. It reminds us of the Arduboy, which can even do 3D graphics if you really push it. Video after the break.

17 thoughts on “Handheld Game Console Puts Processing Power In The Cartridge

  1. I like the idea. If the package has nice controls and a nice display that is almost universally compatible, I2C or SPI, we have you a NRF, ESP, PIC, Propeller, PI, whatever to control it. A ROM chip isn’t much less than a microcontroller.

    1. NES and SNES had their main CPU and GPU in the console. Only additional chips like MMC and Super FX were added to the carts, they weren’t meant to be used as stand alone chips.

      The only consoles that had CPU in the carts AFAIK were Microvision. The main unit had speaker, controller, battery, and LCD. The game ROM and CPU were in separate cartridge.

    1. My thoughts exactly. The Milton-Bradley Microvision console provided power and I/O, while the cartridge s held a microcontroller- usually a tms 1000 or an intel 8051

  2. This is a really good idea. The issue with some of the 8-bit handhelds that have come out recently (like the Arduboy) is that most of the BOM cost is in everything except the processor–screen, buttons, PCB, etc. So it ends up costing around $50, which is hard to justify unless you really want that retro look. And you have to really want it, given that you can grab a DS Lite for less than $30 on eBay.

    Now, if the handheld is just the expensive part of the BOM, and the cartridges can get direct access to everything, then you have something that could play “serious” handheld games. You can still have the intentionally limited AVR-based game for cheap, or you can throw on an STM32 for something on the GB Advanced level. Hook in a cheap SoC, and now you’re around the DS or 3DS level. The BOM cost of the cartridge would probably be higher than Nintendo’s flash carts these days, but not out of line with historical costs. Compared to Nintendo official licensing costs, it may not even be that much different.

    My only issue here is that it looks very limited at this point. Not a great form factor, screen is pretty small, buttons are limited. But it could be the basis for something interesting.

    1. I would second that. My Kia uses resistor dividers in the steering wheel buttons and they sometimes do the wrong function when I press them when it’s too hot or cold outside. At least once it was something I don’t have a button for, volume up or next song button muted my radio.

    1. Avoid I2C unless necessary. It’s excruciatingly slow for single-CPU game consoles. Use SPI even if it means using a 3-to-8 decoder for the chip select lines.

      Lots of DIY console projects starts with I2C parts then learn this the hard way.

      It might be fine for a Wii (nunchucks) when you got a co-processor in each wiimote that got nothing better to do during the frame than send address bytes and wait for responses but for a screen and other peripherals it gets close to a slideshow.

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