USB Volume Control

If you buy expensive computer speakers, they often have a volume knob you can mount somewhere on your desk so you aren’t dependent on the onboard volume control. [Kris S] decided to build his own version of the remote volume control. Not surprisingly, it uses an Arduino-compatible Digispark board and a rotary controller. The Digispark (that [Kris S] bought for $2) is compatible with the Adafruit Trinket. This is key because the Trinket libraries are what make it easy to send media keys over the USB (using the HID interface) to control the volume.

Really, though, the best part of the build is the good looking knob made out of a pill bottle (see the video below). The micro Digispark is small enough to fit in the lid of the pill bottle, and some wax and pellets add some heft to the volume control. Continue reading “USB Volume Control”

Controlling Mains Power Rube Goldberg Style

[g3gg0] has some nice radio equipment including an AOR AR-5000 receiver and a HiQ SDR. They are so nice that it appears they lack an on/off switch. [g3gg0] grew tired of unplugging the things, and decided to nerdify his desk with a switch that would turn his setup on and off for him. He decided to accomplish this task by emulating the Scroll, Number and Caps Lock LEDs on his keyboard via a Digispark board. He uses the LEDs to issue commands to the Digispark allowing him to control a 5V relay, which sits between it and the AC.

Starting off with some USB keyboard emulation code on the Digispark, he tweaked it so he could use the Scroll Lock LED as sort of a Chip Select. Once this is pressed, he can use the Caps Lock and the Number Lock LED to issue commands to the Digispark.

It’s programmed to only stay on for a total of 5 hours in case he forgets to turn it off. Let us know what you think about this interesting approach.

The Digistump Oak; An ESP8266 On Kickstarter

When it was first released, the ESP8266 was a marvel; a complete WiFi solution for any project that cost about $5. A few weeks later, and people were hard at work putting code on the tiny little microcontroller in the ESP8266 and it was clear that this module would be the future of WiFi-enabled Things for the Internet.

Now it’s a Kickstarter Project. It’s called the Digistump Oak, and it’s exactly what anyone following the ESP8266 development scene would expect: WiFi, a few GPIOs, and cheap – just $13 for a shipped, fully functional dev board.

The guy behind the Oak, [Erik Kettenburg], has seen a lot of success with his crowdfunded dev boards. He created the Digispark, a tiny, USB-enabled development board that’s hardly larger than a USB plug itself. The Digispark Pro followed, getting even more extremely small AVR dev boards out in the wild.

The Digistump Oak moves away from the AVR platform and puts everything on an ESP8266. Actually, this isn’t exactly the ESP8266 you can buy from hundreds of unnamed Chinese retailers; while it still uses the ESP8266 chip, there’s a larger SPI Flash, and the Oak is FCC certified.

Yes, if you’re thinking about building a product with the ESP8266, you’ll want to watch [Erik]’s campaign closely. He’s doing the legwork to repackage the ESP into something the FCC can certify. Until someone else does it, it’s a license to print money.

The FCC-certified ESP8266 derived module, cleverly called the Acorn, will be available in large quantities, packaged in JEDEC trays sometime after the campaign is finished. It’s an interesting board, and we’re sure more than one teardown of the Acorn will hit YouTube when these things start shipping.

A Hacker-Friendly Blinky USB Stick

The availability of Smart RGB LED’s, either as individual units, as strips or even as panels, have made blinky light projects with all kinds of color control and transition effects easy to implement using even the simplest of controllers. Libraries that allow control of these smart LEDs (or Smart Pixels as they are sometimes called)  make software development relatively easy.

[overflo] at the Metalab hackerspace in Vienna, Austria recently completed development of usblinky – a hacker friendly blinky USB stick. It can control up to 150 WS2812B smart LED’s when powered via an external power supply, or up to 20 LED’s when powered via a computer USB port. The micro-controller is an ATTiny85 running the Micronucleus bootloader which implements software USB using vUSB. The hardware is based on the DigiSpark platform. The usblinky software sources are available on their Github repo. The section on pitfalls and lessons learned makes for interesting reading.

Metalab plans to run workshops around this little device to get kids into programming, as it is easy enough and gives quick visual feedback to get you started. To round off the whole project, [overflo] used OpenSCAD to design a customizable, 3D printable “parametric orb” which can house the LED strip and make a nice enclosure or psychedelic night light. Check out the mesmerizing video of the usblinky Orb after the break.

Thanks to [papst] for sending in this tip.

Continue reading “A Hacker-Friendly Blinky USB Stick”

Digispark Pro, The Bigger Smaller Dev Board


There has recently been a huge influx of extremely small dev board based on the ATtiny85. This small 8-pin microcontroller is able to run most Arduino sketches,  and the small size and low price of these dev boards means they have been extremely popular. The Digispark was among the first of these small boards, and now the creator is releasing a newer, bigger version dubbed the Digispark Pro.

The new board isn’t based on the ‘tiny85, but rather the ATtiny167. This larger, 20-pin chip adds 10 more I/O pins, and a real hardware SPI interface, but the best features come with the Digispark Pro package. There’s real USB programming, device emulation, and serial over USB this time, and the ability to use the Arduino serial monitor, something not found in the original Digispark.

There are also a few more shields this time around, with WiFi and Bluetooth shields available as additional rewards. Without the shields, the Digi Pro is cheap, and only $2 more per board than the original Digispark.


Body of a Trinket, Soul of a Digispark


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.

Halloween Doorknocker Decoration Hack


If you’re new to hacking, Halloween is a great excuse to get started, and [Chuck] has put together an inexpensive animated Halloween decoration that you can show off on your front door. After scoring a $5 plastic Halloween doorknocker from Wal-Mart, [Chuck] gathered together a small pile of components and then set about breathing some life (death?) into its scary but motionless face.

Though he opted to use a Digispark, you should be able to use any Arduino that is small enough to stuff inside the plastic head. [Chuck] cut some holes in the eyeballs and glued in two RGB LEDs, then cobbled together a quick-and-dirty mount in the mouth area to hold a small servo. The lights and the servo are wired to the Digispark, which turns the lights on and instructs the servo to slam the ring against the door. It’s is battery powered and currently has only two settings: on or off. This should be good enough to scare the kids for this year, but [Chuck] has plans to add a much-needed motion sensor and sound via a Bluetooth connection. 

As simple as this build is, it could be just the thing to get you in the holiday spirit, or to introduce the young hacker in your home to the world of electronics and coding. Check out the short video of the doorknocker after the break, then swing by [Chuck’s] website for detailed build instructions and his Github for the source code. If you’re having trouble finding this doorknocker at Wal-Mart, [Chuck] recommends a similar one on Amazon. Don’t stop now! Make some Flickering Pumpkins too, or if you want a challenge, hack together your very own Pepper’s Ghost illusion.

Continue reading “Halloween Doorknocker Decoration Hack”