Body of a Trinket, Soul of a Digispark

TrinketDigispark

Adafruit’s Trinket and digiStump’s Digispark board are rather close cousins. Both use an ATtiny85 microcontroller, both have USB functionality, and both play nice with the Arduino IDE. [Ray] is a fan of both boards, but he likes the Trinket hardware a bit better. He also prefers the Digispark libraries and ecosystem. As such, he did the only logical thing: he turned his Trinket into a Digispark. Step 1 was to get rid of that pesky reset button. Trinket uses Pin 1/PB5 for reset, while Digispark retains it as an I/O pin. [Ray] removed and gutted the reset button, but elected to leave its metal shell on the board.

The next step was where things can get a bit dicey: flashing the Trinket with the Digispark firmware and fuses. [Ray] is quick to note that once flashed to Digispark firmware, the Trinket can’t restore itself back to stock. A high voltage programmer (aka device programmer) will be needed. The flashing process itself is quite a bit easier than a standard Trinket firmware flash. [Ray] uses the firmware upload tool from the Micronucleus project. Micronucleus has a 60 second polling period, which any Trinket veteran will tell you is a wonderful thing. No more pressing the button and hoping you start the download before everything times out! Once the Trinket is running Digispark firmware, it’s now open to a whole new set of libraries and software.

Cloning the Trinket for a USB Volume Knob

LEDs

A while back, [Rupert] wrote a blog post on using V-USB with the very small, 8-pin ATtiny85. Since then, the space of dev boards for 8-pin micros with USB has exploded, the most recent being Adafruit’s Trinket. [Rupert] liked what he saw with the Trinket bootloader and decided to clone the circuit into a useful package. Thus was born an awesome looking USB volume knob complete with a heavy aluminum knob, rotary encoder, and RGB LED strip.

[Rupert] got his V-USB/ATtiny85/rotary encoder circuit working, and at the expense of a ‘mute’ control, also added an awesome looking RGB LED ring powered by Adafruit’s Neopixels. The PCB [Rupert] fabbed is pretty well suited for being manufactured one-sided. If you’ve ever wanted an awesome volume knob for your computer, all the files are available form [Rupert]’s blog.

Just as an aside, [Rupert] has been working on getting the Trinket bootloader working on the ATtiny84, a very similar microcontroller to the ’85, but with eight analog pins. It’s a neat device that I’ve made a small V-USB breakout board for, but like [Rupert], I’m stuck on porting the bootloader. If anyone has the Trinket/Gemma firmware running on an ATtiny84, send that in. We’ll put it up.

A spinning beachball of doom that you can carry in your pocket

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Need a way to tell the world that you’re mentally ‘out to lunch’? Or what about a subtle hint to others that your current thought process is more important than whatever they are saying? [Caleb Kraft] — who earlier this year bid farewell to Hackaday for a position with EETimes — is heading to the World Maker Faire in New York this weekend, and he decided to build just that device. If you’re heading to Maker Faire too, keep an eye out for his eye-catching Spinning Beachball of Doom. He was inspired by iCufflinks from Adafruit, and ended up with a great little device that is small enough to be worn, or just thrown around for fun.

A couple of weeks ago, we linked you to the Adafruit announcement of their new Trinket product line. [Caleb] wasted no time in finding a use for the tiny microcontroller board. He paired it with the Neopixel LED ring, and had it working with just a tiny tweak to the test code. He then used DesignSpark Mechanical to design a 3D-printed case… the most complicated part of the project. It’s too bad his original plan to power the whole thing with button cells didn’t work out, because it could have been a neat (albeit expensive) upgrade to LED throwies. That said, [Caleb] mentions that a small LiPo battery would be a good alternative.

This is a fun little project that most anyone could throw together in an afternoon. Don’t be surprised if we start seeing these show up more and more.

To see what it looks like in action, check out the video after the break.

Continue reading “A spinning beachball of doom that you can carry in your pocket”

A really, really tiny microcontroller board

Here’s something very cool from the wonderful world of Adafruit: The Trinket, an Arduino compatible microcontroller platform that’s not only small enough to fit in your pocket, it’s small enough to lose in your pocket.

Like the similarly specced Digispark, the Trinket features an ATTiny85 microcontroller with 5 IO pins. Unlike the Digispark, the Trinket is a bit more substantial, featuring 3.3 and 5 Volt regulators along with a real USB port and mounting holes. As this is based on the ‘tiny85, it’s possible to connect this up to I2C and SPI sensors and peripherals

One thing to note about the Trinket is the fact that it’s so cheap. Either version of the Trinket goes for about $8, inexpensive enough to simply leave in a project when you’re done with it. Given the cool stuff we’ve already seen created with the Digispark, including a homebrew stepper motor and an Internet meme and lame pun assessment tool, we can’t wait to see what’s made with the Trinket,