An incredibly small gaming console with cartridges, each bearing an ATtiny10.

2024 Tiny Games Contest: An Epic Minimalist Entertainment System, Indeed

September 8, 2024 by Kristina Panos 2 Comments

One way to keep things tiny is to make a system with cartridges where the brain lives on each cartridge instead of the platform itself. [Michael]’s Epic Minimalist Entertainment System (EMES) is one of those, and boy, is it tiny. EMES makes use of the ATtiny10, and they don’t get much AT-tinier than that.

This nearly microscopic console uses an equally Lilliputian display — a Plessey GPD340 vintage LED display, in fact. (Check out [Michael]’s reverse engineering project if you want to play around with these.) There are four ultra-small buttons for control and a buzzer for sound.

Now, the ATtiny10 is an 8Mhz microcontroller with 1KB of flash and 32 bytes of RAM. It has an 8-bit ADC and a somewhat surprisingly high four GPIO pins. But of course, that’s not enough. Not with the display, the four buttons, and the buzzer, so [Michael] had to come up with a way to multiplex everything to four GPIOs.

PB0 is shared between the buttons and the display’s serial data input. PB1 cleverly outputs the same PWM for both the brightness control and the buzzer. When the buzzer is needed, [Michael]’s code switches to a lower frequency and adjusts the duty cycle of the display to keep it readable. PB2 and 3 are serial clock inputs for the two display halves. Be sure to check it out the heated PONG action in the video after the break!

There’s still a little bit of time to enter the 2024 Tiny Games Contest! You have until Tuesday, September 10th, so head on over to Hackaday.IO and get started!

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Old Dot-Matrix Displays Give Up Their Serial Secrets

June 4, 2024 by Dan Maloney 11 Comments

If there’s one thing we like better around here than old, obscure displays, it’s old, obscure displays with no documentation that need a healthy dose of reverse engineering before they can be put to use. These Plessey dot-matrix displays are a perfect example of that.

We’re not sure where [Michael] scored these displays, but they look fantastic. Each 8-pin DIP has two 5×7-matrix, high-visibility LED displays. They bear date codes from the late 80s under the part number, GPD340, but sadly, precious little data about them could be dredged up from the Interwebz. With 70 pixels and only six pins after accounting for power and ground, [Michael] figured there would be a serial protocol involved, but which pins?

He decided to brute-force the process of locating them, using a Pico to sequentially drive every combination while monitoring the current used with a current sensor. This paid off after only a few minutes, revealing that each character of the display has its own clock and data pins. The protocol is simple: pull the clock and data pins high then send 35 bits, which the display sorts out and lights the corresponding pixels. The video below shows a 12-character scrolling display in action.

Plessey made a lot of displays for military hardware, and these chunky little modules certainly have a martial air about them. Given that and the date code, these might have come from a Cold War-era bit of military hardware, like this Howitzer data display which sports another Plessey-made display.

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