Fuzzy time used to keep the kids in bed

May 10, 2012 By Leave a Comment

Like many parents, [Mike Tsao] is plagued by his kids’ urge to rise like the dead long before he’s ready to wake up. In an effort to preserve sanity, he built this clock to let the young ones know when it’s okay to get out of bed. Fittingly, he calls it the OK-Wake.

You may notice that the clock doesn’t have a display. That’s because his children are still too young to tell time (this is the foundation for needing a custom clock). Instead, that LED acts as the feedback. At night it will be off. Starting ninety minutes before it’s time to wake the LED will begin to pulse red, increasing in frequency as the target time approaches. When it’s okay to get out of bed the LED turns green and exhibits a pleasant “breathing” behaviour.

An ATtiny25 drives the device, along with an RTC chip. The single button is used to set the alarm. Actual time doesn’t really matter at all. Instead, the button just sets the alarm for twelve hours from when it’s pressed.

Filed Under: clock hacks Tagged With: , , ,

Light programming for a clock

May 8, 2012 By Leave a Comment

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So at first glance we were thinking there wasn’t much special about this clock. It’s based on an Arduino and displays the time using a character LCD screen. But then we realized that there’s no battery-backed RTC and no buttons. How the heck do you set the time on this thing? [Mossblaser] is using a light programmer to set the time using a computer screen.

We’ve tried nearly the same data transfer technique before, using a white and black flashing computer screen to push Manchester encoding to a light dependent resistor. We were met with limited success, but you can see that [Mossblaser’s] rig is much more reliable and we think there’s a few reasons behind this. First, he’s only sending five bits per seconds, a very slow speed when it comes to digital transmissions. This helps to make up for slow LCD screen refresh. Also, the LDR is surrounded by material on the back of the case that will help to block out ambient light. And finally, he’s using a smaller part of the screen instead of flashing the whole thing. This may result in more accurate timing. You’ve got to admit, this is pretty slick!

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Filed Under: clock hacks, Microcontrollers Tagged With: , , , ,

Wristwatch measures your perception of time; also tells time

May 8, 2012 By Leave a Comment

This wristwatch is hiding a lot of features in its hardware and its software. It’s called the TicTocTrac and it’s a Senior project for a pair of students at Cornell University. Judging from the sheer volume and quality of the project documentation we wonder if someone has a science writing career ahead of them? Be we digress… It’s a clock and we love it!

First off, this does more than just tell the time. In fact, that’s almost an ancillary function in this case. The wristwatch is more of a metering device to record your own time-based behaviors. Find yourself checking your watch frequently as the lunch break approaches? This watch records that activity and you can later graph the data. This allows you to analyze how you percieve the passage of time. The more often you check the time, the slower you feel time progressing. The documentation does a much better job of describing this than we have time for, so check it out.

On the hardware side of things we’re quite impressed. The housing is 3D printed. It hides two half-circle PCBs below the full-circle PCB face plate. The half-boards leave space for a tiny rechargeable battery, and host a vibrating motor and RTC chip. Instead of using buttons, there’s a piezo sensor which detects when you tap on the top of the watch.

Filed Under: clock hacks Tagged With: , , , , , ,

Six-digit VFD alarm clock

May 7, 2012 By Leave a Comment

[Haris Andrianakis] just finished building this very clean-looking vacuum fluorescent display clock. It shows six digits using IV-11 tubes, and also has a half-dozen RGB LEDs to spice things up (check out the video after the break for an example). An ATmega168 drives the device, controlling the display and serving as a battery-backed real-time clock.

As with any tube-based clock there’s a fair amount of work that goes into driving the display. Each tube has a filament which requires 1.2V, and the segments themselves need 60 volts to light up. The microcontroller is not hard to protect; this is done with a series of transistor-based circuits used for switching. But the need for three voltages (to power microcontroller, filament, and segments) means a more complex PSU design. [Haris] chose to use a MAX6921 to simplify the process.

If you’re considering building something like this, we’d recommend looking for some 12-segment tubes. As we’ve seen before, they can display letters as well as numbers in case you wish to repurpose the device in the future.

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Filed Under: clock hacks Tagged With: , , ,

LED clock lights up a dead Mac Mini

April 30, 2012 By Leave a Comment

[Professor Shadoko’s] Mac Mini died. But since the case designs on Apple products are half the reason to buy them, he decided to reuse the enclosure by turning it into this clock (translated).

As with the binary clock we saw yesterday, this one uses a bunch of LEDs to display the time, but it does it in a way that’s a bit more readable if you know what you’re looking for. The face has been divided up into two columns. On the left is hours, then minutes and seconds in increments of five. To the right is AM/PM, with minutes and seconds in increments of one. If we’re doing this right, the time seen above is 10:23:42 PM on April 28th, 2012. The white LEDs below the date act as a digital pendulum, scrolling left and right as the seconds tick by.

The display uses two MAX7219 LED drivers to control the grid which is build on a big hunk of protoboard. An Arduino ties the whole system together with a Chonodot for accurate time keeping. There’s even an ambient light sensor which adjusts the LED intensity to make this readable in direct sun, or the dark of night. See a demo clip embedded after the break.

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Filed Under: clock hacks, macs hacks Tagged With: , , , ,

A novel binary clock from Hackaday's own

April 29, 2012 By Leave a Comment

Hackaday’s very own [Mike Szczys] just shared an awesome binary clock he’s been working on. Unlike a normal binary clock that is only readable by self-admitted geeks and nerds, [Mike]’s clock is nearly comprehensible by the general population.

There are 12 lines of three LEDs around the face of [Mike]’s clock. These LEDs represent the time in minutes in binary – the inner LED is 1, the middle LED is 2, and the outer LED is 4. Adding up each of the LEDs around the clock face gives the number of minutes passed since the top of the hour.

To display the hour, [Mike] used a red/blue bi-color LED in the center of each line of LEDs. For example, at 1:03 the one ‘o clock hand will have a blue LED in the first position and a purple LED in the second position. A minute later at 1:04, this changes to blue, red, blue.

If that is a little confusing, there’s a wonderful video demonstrating the pattern of LEDs throughout the hour.

For such an interesting clock, the build is fairly simple – just an ATtiny44 with an STP16CP05 LED driver. Time is kept with a battery-backed MCP7940 real-time clock, and power is provided by a simple USB port.

[Mike] had enough boards manufactured for several dozen clocks, but only had enough parts (and patience) to solder up four clocks. You can check out the time-lapse of him going to town with a soldering iron on one of these boards after the break. As with all good builds, the code and schematics are provided on GitHub if you’d like to make your own.

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Filed Under: clock hacks, led hacks Tagged With: , , , ,
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