Master Clock System Uses All Logic, No Microcontrollers

October 17, 2010 by Mike Szczys 17 Comments

What you see above is a master clock. It is the center of a system that can run an unlimited number of slave clocks, keeping them on-time thanks to its ability to synchronize with an atomic clock. [Brett Oliver] put together the project back in 2005 using digital logic chips, and no programmable microcontrollers. This includes everything from the binary decoders that drive the 7-segment displays, to the radio transceiver board that gathers the atomic clock data, to the various dividers that output 1 second, 2 second, 30 second, 1 minute, 1 hour, and 24 hour signal pulses. It’s a well document and fascinating read if you’re interested in digital logic clocks.

Upgrading The Freetronics Twentyten With A Real-time Clock

October 7, 2010 by Caleb Kraft 10 Comments

[John Boxall] finds himself doing a fair amount of projects that require a realtime clock. He does fast and frequent prototyping, usually using the Freetronics twentyten which is an Arduino alternative that boasts a few features like a nice prototyping area, edge visible LEDs, and Mini USB. What is lacking, however, is a real-time clock. Instead of making another shield type system, he just wanted to permanently add this feature to his board. He shares the whole process is photographed and explained quite well for anyone who would want to follow along.

Spinning POV Clock Done Oh-so-right

October 3, 2010 by Mike Szczys 30 Comments

[Kizo] built an extraordinary persistence of vision clock. The design uses a PC cooling fan to spin the propeller-like PCB. As it goes around, a hall effect sensor synchronizes the illumination of the LEDs to draw the display. Power for the rotating electronics is transferred wirelessly via a transformer on the base and coil on the spinning board. The final version uses an ATmega324 microcontroller running at 20 MHz and has an IR receiver for changing the settings. The 3000 lines of code bring a lot of bells and whistles, including a menu system with a huge amount of settings from tweaking the clock display, to font selection for scrolling messages. Take a look at the demo after the break. The double-sided board looks like it’s pretty difficult to etch at home, but as you can see from the forum post (translated), [Kizo] did a great job on this build from start to finish. Continue reading “Spinning POV Clock Done Oh-so-right” →

Matrix Clock Is A Breadboarding Win

September 22, 2010 by Mike Szczys 23 Comments

Normally when we feature a clock made with a 32×8 LED matrix we’d load up an image of the display for the banner photo. But this time around we were so impressed by [JB’s] breadboard work we had to use this image. We see an ATmega168, three buttons, three LEDs, a piezo buzzer, 32.768 kHz crystal, smoothing capacitor, and a few resistors; everything he needed to keep time and display it on the matrix module. If this is just going to sit on your bookshelf for a while it’s a great alternative to point-to-point soldering on a protoboard. Nice work fitting it all on there [JB].

Analog Style LED Clock

September 13, 2010 by Caleb Kraft 17 Comments

We spied this pretty LED clock this morning and were impressed with how cleanly it was constructed. It was built to mimic an analog clock, so you have the typical hour markings and a minute and hour hand. The minute hand stays in each position for roughly 2 to 3 minutes. The brains behind all those LEDs are a PIC 16f877 with a DS1307 realtime clock. Over all, [WellyBoot] soldered 169 LEDs into place, and did it in a nice clean fashion. We suspect that if we had done it, it would resemble a spaghetti pile. You can see the schematics and build pictures on his site, or watch a video of it in action after the break.

[via HackedGadgets]

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Equinox Clock

September 7, 2010 by Mike Szczys 34 Comments

The Equinox clock is made up of simple parts but a combination of fine design and precision make it a gem of a timepiece. The guts are made up of an Arduino, a DS1307 real time clock, twelve LED drivers, and sixty RGB LEDs. These combine with a capacitive touch interface to tell the time using three lit blocks for the hours, one for the minutes, and a fading block for the seconds. See for yourself after the break.

To our delight, [Bram Knaapen] shared the specifics of the case. The black ring that makes up the body was laser cut and spray painted. He uses small blocks of acrylic that have been sandblasted to diffuse the light. This is also a great example of clean circuitry using interconnects between the different circuit boards.

We always enjoy seeing clocks no matter what level of finish is involved, but great design is something that makes us want to hang a project on the wall rather than stow it in a parts bin.

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Meter Clock Using The TI Launchpad

September 2, 2010 by Mike Szczys 9 Comments

Here’s an analog meter clock using an MSP430G2211 microcontroller. [Doug Paradis] chose this processor because it is the lesser of the two that come with the TI Launchpad. The parts count is fairly low too; a clock crystal, two analog meters, a few buttons, and a voltage regulator.

He’s done a nice job putting this together. We challenge you to give this a try yourself and build on [Doug’s] features. We really liked the calibration subroutine in [Alan’s] multi meter clock. It would be fun to implement that functionality and store the calibration code in the MSP’s flash memory. You can use our ported garage door opener code if you need an example of how to store data in flash.