A Simon game built into an ATtiny84 in a DIP-14 package.

2024 Tiny Games Contest: Spectacular Sub-Surface Simon

September 12, 2024 by Kristina Panos 17 Comments

When you work with tiny things on the regular, they start to seem normal-sized to your hands and eyes. Then, if you work with even smaller packages, stuff like 0603 might as well be through-hole components.

[alnwlsn] is no stranger to the small, having worked almost exclusively with surface mount components for a few years now. Even so, they’ve built up an admirable stock of DIP chips, including the ATtiny84 DIP-14 that their incredible Simon game is built into.

How in the world did [alnwlsn] accomplish this? As you’ll see in the video after the break, the answer lies in milling, but with the motors disconnected and manually turning the knobs.

Soldering didn’t require anything special, just the usual suspects like a fine-tipped iron, an X-acto knife, some tweezers, and a few other things like a hot air gun for soldering fine wires to the leadframe. Oh, and of course, really steady hands, and lots of patience.

The 2024 Tiny Games Contest officially closed on Tuesday, September 10th. We’ll have the results out as soon as possible. Best of luck to all who entered!

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A small PCB with a microcontroller, two 7-segment LED displays, a speaker and some buttons

Hunt The Lunpus Is An ATtiny-Based Minimalist Game Console

July 22, 2022 by Robin Kearey 9 Comments

In a world where game consoles come with ever-higher resolutions and ever-faster frame rates, it’s refreshing to see someone going in the opposite direction: [Doug McInnes]’s latest project is a tiny handheld game console with probably the lowest-resolution graphics possible. Hardware-wise, it’s a small PCB containing an ATtiny84, two seven-segment LED displays, a speaker and a handful of buttons. It’s the software that gives this project its magic, and all of it is available on GitHub, along with schematics and a PCB layout.

The game is called Hunt the Lunpus, and as the name suggests it’s inspired by the 1970s classic Hunt the Wumpus. The player moves through a maze of interconnected rooms, trying to avoid slime pits and marauding bats while searching for the Lunpus, a sleeping monster that will eat the player unless they defeat it first by shooting it with arrows. Four pushbuttons provide directional control, with a fifth serving as an “action” button to start the game and fire those arrows.

Whereas Wumpus was originally a text-based adventure game, Lunpus is fully graphical: the seven-segment displays indicate the cave’s walls, and flash in different ways to alert the player to the various hazards. [Doug] explains the events as they happen in the video embedded below; while it might take a bit of practice to find your way at first, we can already picture ourselves wandering through the caves with our quiver full of arrows, ready to hunt some Lunpus. Who needs 4K graphics, anyway?

If you’re into minimalist game consoles, there’s plenty to choose from: the LEDBOY renders Space Invaders on just a few LEDs, while TWANG needs nothing more than a single LED strip. You can also explore more mazes on this 8×8 LED matrix, or even hunt Wumpuses in a slightly-higher resolution.

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Tiny Talisman Warns Wearer About UV Exposure

November 14, 2021 by Dan Maloney 14 Comments

Given how important our Sun is, our ancestors can be forgiven for seeing it as a god. And even now that we know what it actually is and how it works, it’s not much of a reach to think that the Sun pours forth evil spirits that can visit disease and death on those who bask too long in its rays. So an amulet of protection against the evil UV rays is a totally reasonable project, right?

As is often the case with [mitxela]’s projects, especially the more bedazzled ones, this one is approximately equal parts electronics and fine metalworking. The bulk of the video below focuses on the metalwork, which is pretty fascinating stuff. The case for the amulet was made from brass and sized to fit a CR2032 coin cell. The back of the amulet is threaded to act as a battery cover, and some fancy lathe work was needed there. The case was also electroplated in gold to prevent tarnishing, and lends a nice look when paired up with the black solder mask of the PCB.

On the electronics side, [mitxela] took pains to keep battery drain as low as possible and to make the best use of the available space, choosing an ATtiny84 to support a TTP223 capacitive sensing chip and a VEML6075 UV sensor. The touch sensor allows the wearer to wake the amulet and cycles through UV modes, which [mitxela] learned were not exactly what the sensor datasheet said they were. This required a few software hacks, but in the end, the amulet does a decent job of reporting the UV index and looks fantastic while doing it.

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Tiny Two-Digit Thermometer Has Long Battery Life

May 29, 2019 by Donald Papp 20 Comments

Like most of his work, this tiny two-digit thermometer shows that [David Johnson-Davies] has a knack for projects that make efficient use of hardware. No pin is left unused between the DS18B20 temperature sensor, the surface mount seven-segment LED displays, and the ATtiny84 driving it all. With the temperature flashing every 24 seconds and the unit spending the rest of the time in a deep sleep, a good CR2032 coin cell should power the device for nearly a year. The board itself measures only about an inch square.

You may think that a display that flashes only once every 24 seconds might be difficult to actually read in practice, and you’d be right. [David] found that it was indeed impractical to watch the display, waiting an unknown amount of time to read some briefly-flashed surprise numbers. To solve this problem, the decimal points flash shortly before the temperature appears. This countdown alerts the viewer to an incoming display, at the cost of a virtually negligible increase to the current consumption.

[David]’s project write-up explains how everything functions. He also steps through the different parts of the source code to explain how everything works, including the low power mode. The GitHub repository holds all the source files, and the board can also be ordered direct from OSH Park via their handy shared projects feature.

Low power consumption adds complexity to projects, but the payoffs can easily be worth the time spent implementing them. We covered a detailed look into low power WiFi microcontrollers that is still relevant, and projects like this weather station demonstrate practical low power design work.

Mains Power Supply For ATtiny Project Is Probably A Bad Idea

April 2, 2019 by Dan Maloney 45 Comments

When designing a mains power supply for a small load DC circuit, there are plenty of considerations. Small size, efficiency, and cost of materials all spring to mind. Potential lethality seems like it would be a bad thing to design in, but that didn’t stop [Great Scott!] from exploring capacitive drop power supplies. You know, for science.

The backstory here is that [Great Scott!] is working on a super-secret ATtiny project that needs to be powered off mains. Switching power supplies are practically de rigueur for such applications, but compared to the intended microcontroller circuit they are actually quite large, and they’ve just been so done before. So in order to learn a thing or two, [Scott!] designed a capacitive dropper supply, where the reactance of the cap acts like a dropping resistor to limit the current. His first try was just a capacitor in series with an LED; this didn’t end well for the LED.

To understand why, he reverse-engineered a few low-current mains devices and found that practical capacitive droppers need a few more components, chiefly a series resistance to prevent inrush current from getting out of hand, but also a bridge rectifier and a zener to clamp things down. Wiring up all that resulted in a working capacitive dropper supply, but a the cost of as much real estate as a small switcher, and with the extra bonus of being potentially lethal if the power supply is plugged in the wrong way. Side note: we thought German line cords were polarized to prevent this, but apparently not? (Ed Note: Nope!)

As always, even when [Great Scott!]’s projects don’t exactly work out, like a suboptimal 3D-printed BLDC or why not to bother building your own DC-AC inverter, we enjoy the learning that results.

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Rubber Duck Debugging The Digital Way

June 10, 2018 by Dan Maloney 16 Comments

Anyone who slings code for a living knows the feeling all too well: your code is running fine and dandy one minute, and the next minute is throwing exceptions. You’d swear on a stack of O’Reilly books that you didn’t change anything, but your program stubbornly refuses to agree. Stumped, you turn to the only one who understands you and pour your heart out to a little yellow rubber duck.

When it comes to debugging tools, this digital replacement for the duck on your desk might be even more helpful. Rubber duck decoding, where actually explaining aloud to an inanimate object how you think the code should run, really works. It’s basically a way to get you to see the mistake you made by explaining it to yourself; the duck or whatever – personally, I use a stuffed pig– is just along for the ride. [platisd] took the idea a step further and made his debugging buddy, which he dubs the “Dialectic Ball,” in the form of a Magic 8-Ball fortune teller. A 3D-printed shell has an ATtiny84, an accelerometer, and an LCD screen. To use it, you state your problem, shake it, and read the random suggestion that pops up. The list has some obvious suggestions, like adding diagnostic print statements or refactoring. Some tips are more personal, like talking to your local guru or getting a cup of coffee to get things going again. The list can be customized for your way of thinking. If nothing else, it’ll be a conversation piece on your desk.

If you’re more interested in prognostication than debugging, we have no shortage of Magic 8-Ball builds to choose from. Here’s one in a heart, one that fits in a business card, and even one that drops F-bombs.

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Big Mouth Billy Bass Channels Miley Cyrus

April 14, 2018 by Rich Hawkes 12 Comments

Here’s a Big Mouth Billy Bass with extra lip thanks to Alexa. If you’re not already familiar, Big Mouth Billy Bass is the shockingly popular singing animatronic fish designed to look like a trophy fish mounted to hang on your wall. In its stock condition, Billy uses a motion sensor to break into song whenever someone walks by. It’s limited to a few songs, unless you like to hack things — in which case it’s a bunch of usable parts wrapped in a humorous fish! Hackaday’s own [Bob Baddeley] combined the fish with an Amazon Echo Dot, connecting the two with an ATtiny84, and having Billy speak for Alexa.

[Bob] had a few problems to solve, including making Billy’s mouth move when there was audio playing, detecting when the Echo was on, moving the motors and playing the audio. After a bit of research and a lot of tweaking, a Fast Fourier Transform algorithm designed for the ATtiny was used was used to get the mouth moving. The mouth didn’t move a lot because of the design of the fish, and [Bob] modified it a bit, but there was only so much he could do.

It’s all well and good for the fish to lie there and sing, but [Bob] wanted Billy to move when Alexa was listening, and in order the detect this, the best bet was to watch for the Dot’s light to turn on. He tried a couple of things but decided that the simplest method was probably the best and ended up just taping a photo-resistor over the LED. Now Billy turns to look at you when you ask Alexa a question.

With a few modifications to the Dot’s enclosure, everything now fits inside the original mounting plaque and, after some holes were drilled so the Dot could hear, working. Billy has gone from just a few songs to an enormous entire library of songs to sing!

We’ve seen Alexa combined with Big Mouth Billy Bass before, but just demos and never an excellent guide like [Bob’s]. The nice thing about this guide is that once you’ve hacked the hardware, it’s a breeze to add new functionality using Alexa skills.

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