ATtiny Hacks

275 Articles

Light Switch For The Lazy

December 10, 2017 by 39 Comments

[Will Donaldson] has whipped up a quick hack for anyone thinking of dipping their toe into home automation — or otherwise detest flicking off the bedroom light before navigating their way to their bed: a remote control light switch!

This remote switch uses a sg90 servo, an Arduino Uno, and pairs of ATtiny85s with HC-05 Bluetooth modules assembled on protoboards. The 3D printed mount screws easily on top of a standard light switch cover while still allowing the switch to be flipped the old-fashioned way. It’s also perfect as a temporary solution — [Donaldson] is presently renting his apartment — or for those unwilling to mess with the mains power of their abode.

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Upgrading A USB Soldering Iron!

December 4, 2017 by 14 Comments

Seeing the popularity of the TS-100 soldering iron, GitHub user [ole00] found himself desirous of a few of its features, but was put off by its lack of a power supply. What is a hacker to do? Find a cheaper option, and hack it into awesomeness.

[ole00] stumbled across the inexpensive ZD-20U and — despite a handful (sorry!) of issues — saw potential: it’s compact, lightweight, and powered via a USB power cable. Wanting to use as much of the ZD-20U’s original board as possible, the modifications were restricted to a few trace cuts and component swaps. The major change was swapping out the 555 timer IC controlling the iron with am ATtiny13a MCU to give it a bit more control.

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Continuity Tester Uses The ATtiny85’s Comparator

November 25, 2017 by 11 Comments

There’s an inside joke among cyclists – the number of bikes you need is “n+1”, where “n” is your current number of bikes. The same probably also applies to the number of tools and equipment a hacker needs on their workbench. Enough is never enough. Although [David Johnson-Davies] has a couple of multimeters lying around, he still felt the urge to build a stand-alone continuity tester and has posted details for a super-simple ATtiny85 based Continuity Tester on his blog. For a device this simple, he set himself some tall design goals. Using the ATtiny85 and a few SMD discretes, he built a handy tester that met all of his requirements and then some.

The ATtiny85’s Analog Comparator function is perfectly suited for such a tester. One input of the comparator is biased such that there is a 51 ohm resistor between the input and ground. The output of the comparator toggles when the resistance between the other input and ground is either higher or lower than 51 ohms. Enabling internal pullup resistors in the ATtiny85 not only takes care of proper biasing of the comparator pins, but also helps reduce current consumption when the ATtiny85 is put to sleep. The test current is limited to 100 μA, making the tester suitable for use in sensitive electronics. And enabling the sleep function after 60 seconds of inactivity reduces standby current to just about 1 μA, so there is no need for a power switch. [David] reckons the CR927 button cell ought to last pretty long.

For those interested in building this handy tester, [David] has shared the Eagle CAD files as well as the ATtiny85 code on his Github repository or you could just order out some boards from OSHpark.

DIY Pyrography Power Supply

November 2, 2017 by 25 Comments

Ever wanted to try your hand at wood burning? If you already threw away your first soldering iron—you know the one: plugged straight in to the wall, no temperature control, came with a thick piece of tin foil to rest it on—don’t despair. Pyrography pens don’t cost that much. The variable power supply they plug into, though: that’s another story. Those cost more than they probably should.

[td0g] took the plunge into pyrography a while back, and wanted to build his own controller from an old ATX power supply. Why not? It should be more than capable of doing the job. Even the most heavy-duty pyrography pens only draw 10A, and the 3.3V line showed to be rated for 30A. All [td0g] had to do was add a PWM with a MOSFET and a ‘Tiny85.

The project nearly became Fail of the Week fodder after [td0g] saw huge voltage spikes across the MOSFET. A 47kΩ resistor took care of those, and a heat sink salvaged from the junk bin will prolong the transistor’s life. [td0g] added a push button that cycles through five heat settings, and an LED to show the status. After that, all he had to do was add a male RCA input to connect the pens he already has.

Okay, so you wouldn’t be caught dead dropping money on some fancy power supply for this new hobby. Don’t want to buy pens, either? Roll your own from a plasma arc lighter.

Bluetooth Bedroom Clock!

November 1, 2017 by 12 Comments

When [decino]’s old bedroom clock finally bit the dust, he built himself a new one from scratch for fun and functionality.

Initially, he wanted to solder Adafruit NeoPixel lights onto four prototype boards, using a mini-USB for power and a DS1307 to keep the time. However, after soldering the board for the first digit and realizing that carrying on with the other three would be a huge pain, he switched to etching the boards instead — a far more efficient solution. In keeping with this time-saving mindset, he added a Bluetooth module that would allow him to update the clock from his phone whenever the DS1307 started dropping minutes or whenever daylight savings time is in effect.

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Test your speed

Modern Strongman Games Test Your Speed Instead

September 30, 2017 by No comments

Step right up! What would a Makerfaire be without some carnival games? And being a Makerfaire, they could of course be modernized versions. In [avishorp]’s case, he made a series of games that test your speed and look very much like the old strongman game, aka high striker or strength tester.

In the strongman game, you smash a lever with all your might using a hammer. A puck on the other end of the lever then shoots up a tower, hopefully high enough to hit a bell, winning you a prize. In [avishorp]’s games the puck, tower and bell are all replaced with an LED strip. In the swipe game, the faster you swipe your hand sideways over two optical proximity sensors, the higher the LEDs light up. In the drum game, the speed with which you drum on a rubber disk with embedded accelerometer, the higher the LEDs light up. The chase and response games both involve buttons that you have to rapidly hit, to similar effect.

For the brains, each game is controlled by an Adafruit Trinket board. [Avishorp] chose to use the PlatformIO IDE instead of the Arduino IDE to write them, preferring its modern editor, but he didn’t like that it doesn’t print and that it doesn’t tell you the final file size. The latter issue caused him to overwrite the bootloader, something that he understandably considered a major inconvenience.

Check out his page for more details, Fritzing diagrams, links to code, and all game videos. Meanwhile we’ve included clips of the drum and swipe games below.

And if it’s more carnival games you’re looking for, how about this adult-sized Sit ‘n Spin made using a rear differential and axle assembly out of an old car or truck. Or maybe you prefer something less likely to make you woozy, in which case you can try fishing with the Bass Master 3000.

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