Thumbs Up for This Custom Atari 5200 Controller

It may be nearly 40 years old, but the Atari 5200 still inspires legions of fans to relive the 8-bit glory days of their youth. There was much to love about the game console, but the joystick-and-keypad controllers were not among its many charms. The joystick didn’t auto-center, the buttons were mushy, and the ergonomics were nonexistent.

Retro-aficionados need not suffer in silence, though, thanks to this replacement controller for the Atari 5200. [Scott Baker] didn’t want to settle for one of the commercial replacements or, horrors, an adapter for the old PC-style joystick, so he rolled his own. Working from the original Atari schematics, [Scott] devised a plan for using a readily available thumbstick controller as the basis for his build. The essential problem was how to adapt the 10k pots on the new joystick to work in an environment expecting 500k pots, which he solved using an analog to digital and back to analog approach. The ADCs on an ATtiny85 convert each joystick pot’s voltage to a digital value between 0 and 255, which is sent to a 100K digital potentiometer. A little fiddling with RC constants brings it back in line with what the console expects. The thumbstick and buttons live on a custom PCB – kudos to [Scott] for designing an ambidextrous board. The video below shows the design and the finished product in action.

[Scott] is on a bit of a 5200 kick these days; he just finished up a Raspberry Pi multi-cartridge for the venerable console. His controller should make retro-gameplay on the console a little easier on the hands.

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Hackaday Prize Entry: Ears On The Back Of Your Head

From context clues, we can tell that [TVMiller] has been in and around NYC for some time now. He has observed a crucial weakness in the common metropolitan. Namely, they deafen themselves with earphones, leaving them senseless in a hostile environment.

To fix this problem, he came up with a simple hack, the metrophone. An ultrasonic sensor is hung from a backpack. The user’s noise making device of choice is plugged into one end, and the transducer into the other. When the metropolitan is approached from the rear by a stalking tiger or taxi cab, the metrophone will reduce the volume and allow the user to hear and respond to their impending doom. Augmentation successful.

The device itself consists of an off-the-shelf ultrasonic sensor, an Arduino, and a digital potentiometer. It all fits in a custom 3D printed enclosure and runs of two rechargeable coin cells. A simple bit of code scales the volume to the current distance being measured by the ultrasonic sensor once a threshold has been met.

In the video after the break, you can observe [TVMiller]’s recommended method for tranquilizing and equipping a metropolitan in its natural habitat without disturbing its patterns or stressing it unduly.

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Digitally Controlled Pot Taper

Those twisty knobs connected to potentiometers aren’t necessarily a strict linear progression from one resistance to another. Potentiometers have a taper. Yes, sometimes it’s a linear taper that’s a straight line from one resistance to another, but you can find log (audio) taper pots, and anti-log taper pots. It’s been this way for a hundred years, and now we have a pot with a digitally controllable taper thanks to a guitar pedal that fits in your shoe.

For the last few years, [John] has been hard at work creating the SoulPedal, a shoe insert that’s the wireless, wearable alternative to expression pedals, wah pedals, and every other guitar effects pedal that uses an ankle. [John] got the idea by replacing the light-sensitive resistor in a wah pedal with a force sensitive resistor in his shoe. It worked, but there were wires. Now the SoulPedal is based on a TI SoC +Radio with all the niceties you would expect.

When designing the ‘base station pedal’, [John] realized he had a digital pot with two channels, and the entire device only uses one of these channels. Instead of letting that little bit of silicon go to waste, [John] wired these two digital pots in parallel, allowing the user to customize the taper of a digital pot. If you’re asking yourself, ‘why’, the answer is, ‘because he could.’

It’s an interesting application for sure, and while this digitally controllable pot can replicate the linear, log, and anti-log tapers, the really interesting thing will be to see what non-standard tapers sound and feel like.