Couch to 5K with 1K to spare

In a market full of Fitbits, Misfits, and Fuelbands, it’s easy to get carried away with sophisticated personal fitness tracking technology.  That’s why [André] took a totally different approach with his super simple run tracking device, the C25K machine.

C25K stands for “Couch to 5k” which is a slimmed down exercise schedule designed to gradually bring people who have otherwise no exercise routine up to a level of fitness where they can run a 5k in just 9 weeks.  To keep participants from wearing themselves out too early, the routine specifies a sequence of running and walking periods to be completed in series on specific days.  Though simpler than most fitness plans, it’s still a lot to keep track of especially when you’re sweating so hard you can barely see your stopwatch.

André found a solution using a bare-bones circuit based on the ATTiny2313.  After loading the C25k calendar into its firmware (which takes up less than half of its 2K of flash), he needs only to toggle the dipswitch to select the appropriate day of the program, and the little device (scarcely larger than a key fob) will beep to let him know to switch from running to walking or back again.

Definitely a great project for any hobbyist looking for a geeky way to get in shape.

Lots of seven segment displays with a single ATtiny

7seg

These days they’ve been replaced with character LCD displays or even brightly colored graphical displays, but if you’re trying to display data on one of your projects, there’s nothing like the classic red glow of a red seven segment display. [five volts] got his hands on a few ancient segmented displays, but controlling even one took up more microcontroller pins than he was ready to spare. The solution to this problem was to use a shift register and control multiple segment displays with an 8 pin microcontroller.

[volts] is using an ATtiny13 to control six seven segment displays. Each display is mounted on a hand-etched board, with a shift register and a handful of resistors soldered to the back. By having the microcontroller shift bits down the line, [volts] created an extremely easy to interface 6-digit segment display, and the entire device can be expanded even more.

The board files and schematics are available on [volt]‘s project page. A great project if you’re just starting out to etch your own boards.

Business card draws [ch00f]‘s logo

card

[ch00f] is at it again, expanding the horizons of the art of PCB business cards. This one draws his logo on any computer over a USB port.

The physical design of the card is heavily inspired by [Frank Zhao]‘s card; both use an ATtiny85 and the V-USB package to handle the USB protocol and communications. Instead of typing words into a text editor like [Frank]‘s, [ch00f]‘s card draws the ch00ftech logo in MS Paint or other image editor.

There was a problem with simply emulating the mouse to draw a logo on the screen, though; because different computers have different mouse settings for acceleration, the ch00ftech logo was nearly always distorted. [ch00f] fixed that by emulating an absolute input device, basically turning his business card into a single-function pen tablet.

The logo was traced by hand and put into a few arrays in the firmware. Surprisingly, the logo didn’t take up much space – only 4k of the tiny85’s flash is used. There’s a lot more space for a more complicated drawing, but for now the simple ch00ftech logo (video after the break) will do.

[Read more...]

ShuttAVR can snap a pic or serve as an intervalometer

shuttAVR-intervalometer-hack

This project started as a simple microcontroller replacement on this IR camera remote control PCB. But the soldering job went rather badly for [Balthamos] so he changed things up and designed his own simple AVR remote shutter release and intervalometer.

The DIP chip seen with most of its legs bent backwards is the ATtiny25 which makes the system work. It’s patched into the traces for the battery connections, button (on the other side of the board) and the IR LED he’s pinching with his left hand. Point it at a Cannon camera and push the button to snap a photo. But as you can see in the clip after the break it also serves as an intervalometer; letting him take several pictures with a user-defined pause between each. That mode is selected by first pressing and holding the button. Once released the chip waits for a second button press to register the delay. The new circuit still fits in the original case after just a bit of alteration to it.

[Read more...]

LED marquee uses discrete through-hole lights

through-hole-led-marquee

[Michael] built his own LED marquee using individual diodes. Despite his choice to forego the 8×8 or 5×7 modules we often see in these projects, his decision to spin a dedicated PCB saved him a lot of trouble during assembly. Sure, he still had to solder 180 leads on the 9×18 grid of lights, but at least he didn’t have to deal with wiring up the complex display layout.

The chip driving the display is an ATtiny24. You can see that it’s an SMD package and spans one row of the through hole LED footprint. There are way too few pins to drive a multiplexed display of this size. Instead of adding a separate driver IC he decided to design the display to use Charlieplexing. We didn’t see a schematic for the project, but judging from the board images all of the I/O pins are used by either the display itself, or the serial connection provided by that right angle pin header.

LED ice cubes prevent alcohol induced blackouts

cube

On November 23rd last year, [Dhairya] attended a little shindig at MIT. Three drinks into the night, he blacked out and woke up in the hospital the next day. It was an alcohol-induced blackout, and like all parties at MIT, there’s an ingenious solution to [Dhairya]‘s problem.

[Dhairya] came up with an alcohol-aware ice cube made of a coin cell battery, an ATtiny microcontroller, and an IR transceiver are molded into an edible gelatin ice cube. The microcontroller counts the number of sips per drink, and after one glass of adult beverage changes the color of the flashing LED from green to yellow. After two drinks the LED changes from yellow to red, signaling [Dhairya] to slow down.

If [Dhairya] feels the night is too young and keeps on drinking, the IR transmitter signals to his cell phone to send a text to a friend telling them to go take [Dhairya] home.

Less than three weeks after waking up in the hospital, [Dhairya] tested out his glowing ice cubes at another party. Everything performed wonderfully, even if he admits his creation is a little crude. A neat piece of work, and we can’t wait to see an update to this project.

[Read more...]

ATTannenbaum

attiny

It’s that special time of year again where the smell of baking cookies fill the house and shopping mall parking lots are filled with idiots and very angry people. [Kevin] thought it would be a good idea to build an LED Christmas tree and ended up building a great looking tree that’s also very simple.

In the video, the imgur album, and the github, [Kevin] shows us the simplest way to make a color-changing LED Christmas tree. The circuit uses LEDs to drop the voltage and to provide a nice glow around the base of the tree. After that, it’s just an ATtiny13 and some LEDs in a very nice freeform circuit.

Of course, if LED Christmas trees aren’t your thing, [hb94] over on reddit created an LED menorah. Pretty nifty he used an 8-position DIP switch for the circuit. Let’s just hope someone gave him a soldering iron for the last night of Hanukkah.

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