DCF77 Powered Clock Is A Work of Art

December 6, 2013 by Mathieu Stephan 21 Comments

[Brett] just completed his DCF77 Master Bracket Clock, intended to be a backup to an old logic controlled clock he made. For our readers that don’t know, DCF77 is a German longwave time signal whose transmitter is located near Frankfurt (Germany). Every minute, the current date and time are sent on the 77.5kHz carrier signal.

The result, which you can see above, is made using an Ikea lantern, a skeleton clock, an ATmega328 (for Arduino compatibility), a voice recording playback IC (ISD1730), a cheap 20×4 LCD display, a DCF77 receiver module, and many LEDs. We’re pretty sure that it must have taken [Brett] quite a while to get such a nice looking clock. In case the clock loses power from the power supply, 3 AA cells provide battery backup. On the firmware side, making the platform Arduino-compatible allowed [Brett] to use its libraries so the coding was quickly done. Embedded after a break is a video of the final result.

Continue reading “DCF77 Powered Clock Is A Work of Art” →

Heathkit Clock Updated With A PIC32 And GPS

November 1, 2013 by Adam Fabio 46 Comments

One of [Bob’s] most treasured possessions is a Heathkit alarm clock he put together as a kid. Over the years he’s noticed a few problems with his clock. There isn’t a battery backup, so it resets when the power goes out. Setting the time and alarm is also a forward only affair – so stepping the clock back an hour for daylight savings time means holding down the buttons while the clock scrolls through 23 hours. [Bob] decided to modify his clock with a few modern parts. While the easiest method may have been to gut the clock, that wouldn’t preserve all those classic Heathkit parts. What [Bob] did in essence is to add a PIC32 co-processor to the system.

Like many clocks in the 70’s and 80’s, the Heathkit alarm clock was based upon the National Semiconductor MM5316 Digital Alarm Clock chip. The MM5316 operates at 8 – 22 volts, so it couldn’t directly interface with the 3.3V (5V tolerant) PIC32 I/O pins. On PIC’s the input side, [Bob] used a couple of analog multiplexer chips. The PIC can scan the individual elements of the clock’s display. On the PIC’s output side, he used a couple of analog switches to control the ‘Fast’, ‘Slow’, and ‘Display Alarm/Time’ buttons.

Continue reading “Heathkit Clock Updated With A PIC32 And GPS” →

The Greenest Wall-Powered Clock

October 13, 2013 by Brian Benchoff 51 Comments

Some of the most inefficient appliances in the home are AC mains-powered clocks. You can’t exactly turn them off and they use a whole lot of energy considering how often they’re looked at. [t3andy] came up with a great low power AC Mains clock that is only on 3% of the time. As a neat bonus, it also looks really, really cool.

[t3andy] is using a Teensy 3 as the brains of this clock, and the serial interface on the board provides a relatively easy means of setting the time without having to use buttons or tact switches. The clock face consists of 13 neopixels, with two red pixels showing the hour and a single green pixel showing the minutes. The time is measured with a DS3232 I2C real time clock with a battery backup.

The design is remarkably efficient since the LEDs are off 97% of the time, only being lit at the top of the minute. There are provisions for IR control and a PIR sensor to display the time whenever it’s needed, but that would obviously mean a hit to the energy efficiency.

A Cable Box Becomes A Network Time Display

August 7, 2013 by Brian Benchoff 26 Comments

In 2011 [Erkki]’s DVB box gave up the ghost. It had been a fixture of his media center for quite a while, decoding cable and recording shows faithfully for years. A flaky power supply will bring down the mightiest machine, though. and the Topfield box eventually found itself in disuse. One thing [Erkki] liked about this cable box is its wonderful green LED clock – even after the box had been declared dead, he still used it as a clock. Not wanting to keep a faulty machine on life support, [Erkki] decided to strip the guts and replace them with a networked Arduino that receives time over a network

[Erkki] originally used an Arduino and an ENC28J60 Ethernet module to receive time from an NTP server and spit it out onto the LCD display. A full Arduino for this kind of job, especially one that’s a more or less complete project, is a bit overkill so [Erkki] designed a PCB to put his ‘duino to better use.

One interesting bit about this build is that [Erkki] found it completely broken one day. Figuring this was a problem with the microcontroller, he first fried the ATMega with 9 volts – the reasons escape us, however – and started work on programming a new chip. After looking at different ports on his NTP server with a microcontroller, [Erkki] realized he had reset his network switch recently, meaning the previous microcontroller was working perfectly.

In the future, [Erkki] hopes to add some new features to this 8×4 seven-segment display sitting in a large box; something like reading off the temperature, checking IRC and his physical mailbox, and notifying him when someone is at the front door.

Twenty Two Servos And An Awesome Clock

July 3, 2013 by Brian Benchoff 27 Comments

We can never get enough interesting clock builds, and [ebrithil]’s servo clock (Deutsche, Google translation) is up there with the best of them. There’s twenty-two servos in this clock, moving time forward with the mechanistic precision only an Arduino project can.

The digits in [ebrithil]’s clock are constructed like seven-segment displays, only instead of lighting up LEDs, servos turn small bits of paper that are light on one side and dark on the other. Turing the servo 180 degrees changes each segment from one shade to the other, making for an electromechanical seven-segment display.

The servos are controlled by an Arduino Mega connected to a DS1302 real-time clock. One problem [ebrithil] had with this project is having the segments rotate slightly every time someone turned on a light attached to the same circuit. He solved this problem by running the circuit off a perpetually charging cell phone battery, allowing him to take this clock on the go without losing time.

Continue reading “Twenty Two Servos And An Awesome Clock” →

Designing And Building A Wooden Mechanical Clock

March 19, 2013 by Jeremy Cook 16 Comments

Electronics are undoubtedly the basis for our modern society. Leaving out transistor-based devices, and a mechanical clock would be one of the most intricate devices man has come up with. As a Mechanical Engineer, I thought it would be a fun challenge to design and build my own gear-driven clock.

Because clocks have obviously been invented, I wouldn’t be starting from scratch, and I don’t think I could have figured out an escapement on my own. I explain my initial clock escapement and gear reduction design thoughts in this post, and originally getting the escapement to work was my biggest fear.

As seen in the first video after the break, the escapement gear is still a big problem, but not really for the reason I expected. The shaft that the gear sits on seems to be bent, so it allows the escapement to “go free” for part of it’s cycle, losing any sense of accurate timekeeping. Be sure to also check out the second video, especially around 1:50 when I show what happens when an escapement gear goes much faster than a normal clock. Continue reading “Designing And Building A Wooden Mechanical Clock” →

NES Annoyance Timer Makes No Friends At Your Work

March 5, 2013 by Mike Szczys 16 Comments

Still trying to solidify that reputation as the office Grinch? This project will let everyone know you’re a complete jerk in no time. It’s called the 8-bit Annoying Person Remover. It detects when someone enters your office at which point it starts to play the Super Mario Bros. theme song while the display counts down 400 seconds. Just like in the game the music gets faster at the end and when it stops they know it’s time to get the heck out.

The hardware inside isn’t too complicated. An Arduino and a Wave shield do most of the work. The song played is stored on an SD card and can easily be changed. There’s a speaker mounted under the top heat vent of the enclosure. The device defaults to displaying the time of day, but monitors a motion sensor on one side to detect when someone comes through the door. This also works when someone leaves, cutting off the music and resetting the display. Don’t miss a video of it in action after the break.

It’s as if this was made specifically for the Comic Book Guy

Continue reading “NES Annoyance Timer Makes No Friends At Your Work” →