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 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.

A Plessey GPD340 display showing the word 'Hi'.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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Repairing A Hallicrafters S-120

September 8, 2024 by 2 Comments

[MIKROWAVE1] claims he’s not a radio repair guy, but he agreed to look at a malfunctioning Hallicrafters S-120 shortwave receiver. He lets us watch as he tries to get it in shape in the video below. You’ll see that one of his subscribers had done a great job restoring the radio, but it just didn’t work well.

Everything looked great including the restored parts, so it was a mystery why things wouldn’t work. However, every voltage measured was about 20V too low. Turns out that the series fuse resistor had changed value and was dropping too much voltage.

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The Hidden Crystal Method

September 8, 2024 by 24 Comments

Ever been working on a project and get stuck on one of those last little details?  That’s what happened to [Empire of Scrap].  He’s building an Ohio Scientific (OSI) superboard II replica. He wants it to be accurate down to the dates on the chips. It is quite an impressive build.  The problem is the crystal. OSI used large crystals, even by early 1980s standards. The crystal is in a large can with thick pins, like something you’d expect to find in old radio equipment. The problem is that this crystal package isn’t made anymore. 

The crystal had to be exactly 3.932160 MHz, and while [Empire] has a huge collection of vintage crystals, he didn’t have the right one from the 70s. He did, however, have that value in a modern crystal.  

The solution? Hide the new crystal in the can of an older one. The only problem is that crystals are sealed. The bottom appeared to be some sort of plastic or resin.  Gong after it with a side cutter, [Empire] realized it was glass!  Thankfully, none of it got in his eyes, though his hands may have taken a bit of a beating. 

With the old crystal’s shell hollowed out, [Empire] installed the modern device and potted everything in resin. The transplant worked. Now, all that’s left is to fire up the OSI and start hacking. 

Want to build a replica computer but don’t want to hunt down the parts? Check out [Taylor] and [Amy’s] build of this minipet. Regardless of the size of the case, crystals all work in the same way.

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How Hot Is That Soldering Iron?

September 7, 2024 by 8 Comments

It is common these days to have a soldering iron where you can set the temperature using some sort of digital control. But how accurate is it? Probably pretty accurate, but [TheHWCave] picked up a vintage instrument on eBay that was made to read soldering iron temperature. You can see the video below, which includes an underwhelming teardown.

The device is a J thermocouple and a decidedly vintage analog meter. What’s inside? Nearly nothing. So why did the meter not read correctly? And where is the cold junction compensation?

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Should You Run Servo Horns Or Direct Couplings In Your RC Planes?

September 7, 2024 by 22 Comments

Whenever you buy a servo, it usually comes with a little baggie full of various plastic horns. Most of us pick our favorite and use it in our projects. Some of us hack them up, glue them back together, and do all kinds of weird things with them. And others skip them entirely, going for direct drive instead. In a new video, [Dynamix Systems] explores when going direct drive is the right solution.

The video primarily concerns servos as they’re used in the context of aero modeling. In this regard, the video points out that while stock servo horns are easy to use, they can be cumbersome and clumsy. For example, you often end up with horns and control linkages protruding out into the airstream, adding drag and generally making things a bit inelegant. They can also snag on things and easily damage your servos or controls.

Using direct shaft couplers can be a much tidier solution in some respects. The servo can be coupled directly to the axis of motion, allowing it to be hidden inside a wing or tail surface. It can require a little more finesse in installation and design, but they’re much less likely to snag on things or be damaged. There’s also a drag benefit if you do it right. [Dynamix Systems] notes that you’ll want to source some shaft couplers to do this properly, which you can make yourself or buy online fairly easily.

It’s great to see how tidy direct drive really is. We’ve seen some other nifty servo tricks of late, too. Video after the break.

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An Automatic Cat Feeder Built With A 4060 Binary Counter

September 6, 2024 by 14 Comments

We’ve seen a great many cat feeders over the years. Some rely on the Internet of Things, and some rely on fancy microcontrollers. [Larry Cook], on the other hand, built his using a simple 4060 binary counter chip.

The feeder is built out of old plywood, and the whole thing runs off an old 12-volt DC wall wart and a lead-acid battery to keep it going in a power outage. The dry cat food is stored in hopper above a drum, with the drum  rotated by a 12-volt DC gearmotor. The gearmotor is activated on a schedule—either every 4 hours, or every 5.5 hours, depending on setting. There’s then a four-digit 7-segment display for counting the total number of feedings.

The manner of operation is simple. The 4060 binary counter slowly counts up to 8,196 on a 1.11 Hz or 0.83 Hz clock, for four hour or 5.5 hour operation respectively. When it hits that threshold, it fires the gear motor. The gear motor then rotates the drum for one revolution, dumping a preset amount of food. At the end of a revolution, it triggers a hall sensor which resets the circuit.

The best thing about this design? It’s been in service for ten years. [Larry’s] original video is a big contrast to his latest one, but it shows the same feeder doing the same job, all this time.

We love a good cat feeder, and it’s great to see one built with simple old-school parts, too. Video after the break.

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How Much Resolution Does Film Really Have?

September 6, 2024 by 29 Comments

Have you ever scanned old negatives or print photographs? Then you’ve probably wondered about the resolution of your scanner, versus the resolution of what you’re actually scanning. Or maybe, you’ve looked at digital cameras, and wondered how many megapixels make up that 35mm film shot. Well [ShyStudios] has been pondering these very questions, and they’ve shared some answers.

The truth is that film doesn’t really have a specific equivalent resolution to a digital image, as it’s an analog medium that has no pixels. Instead, color is represented by photoreactive chemicals. Still, there are ways to measure its resolution—normally done in lines/mm, in the simplest sense.

[ShyStudios] provides a full explanation of what this means, as well as more complicated ways of interpreting analog film resolution. Translating this into pixel equivalents is messy, but [ShyStudios] does some calculations to put a 35mm FujiColor 200 print around the 54 megapixel level. Fancier films can go much higher.

Of course, there are limitations to film, and you have to use it properly. But still, it gives properly impressive resolution even compared to modern cameras. As it turns out, we’ve been talking about film a lot lately! Video after the break.

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