Johannes’ Numitron GeekWatch features Numitron tubes housed in a hideous 3D printed case:
Numitron tubes are cut-down version of Nixie tubes, but instead of having a wire-mesh anode with a cold-cathode display, uses a seven-segmented indicator commonly found on digital meters and clocks.
Old School Tube Watch - [Link]
This Instructable describes building of a fun and very simple LED clock using Arduino that displays the time to the nearest half hour using LEDs.
Arduino LED clock - [Link]
Elia wrote an article detailing his binary wrist watch project:
I have just finished my binary wrist watch project (well, the new revision anyway). I was surprised at how small I was able to make it compared to last time.
I chose to go with the “super-yellow” color LEDs as they fit the purple OSHpark PCB very nicely. The biggest challenge was actually making a good looking wrist band for the watch. I originally intended to use a design like this but it turned out that due to lack of enough para cord I had left, I went with a simpler design that I had done once before.
DIY binary wrist watch - [Link]
Here’s a voltmeter clock project based on a multimeter clock design by Alan Parekh:
I have used three voltmeters and mounted them on a wooden plinth with a clear Perspex cover to give the clock an industrial look.
I have modified Alan’s code to run on PICBasic Pro version 3. I have also added the following.
Switched display On and Off (keeping battery backup as per Alan’s design) but also allows me to turn meters Off in full power mode.
Synchronization to my Master Clock every 30 seconds
Synchronized LED & Re-Synch LED
Synchronization On & Off
Transistor meter drivers
Separate hourly Chime Circuit
Pulsed “tick tock” seconds sound.
Voltmeter clock project - [Link]
Kerry Wong writes:
DS3232 is an extremely accurate RTC with a guaranteed accuracy of 2.5 ppm (0 °C to 40 °C), which translates into an error of just 80 seconds over the course of a year under the worst case scenario. I had done a few projects using this chip before (you can read about them here).
While by default DS3232 is already very accurate, we can push its accuracy even higher by adjusting its aging offset register (8bit). This adjustment works by adding or subtracting the corresponding capacitance to or from the oscillator capacitor array. The adjustable range is represented as 2′s complement (-128 to 127) and each LSB change corresponds to roughly 0.1 ppm of change in frequency. So the overall adjustment range can be achieved programmatically is roughly ±13 ppm.
DS3232 clock frequency calibration - [Link]
by Shawon Shahryiar @ embedded-lab.com:
Okay firstly the reason I wrote about the clock system instead of I/O ports or something else in this second post of the XMega series is simply because of the fact that without understanding clock configurations you won’t get what you want from your chip. Since XMega’s clock system is software-level configurable and complex at first, it makes itself the first priority module before anything else.
XMega Clock System - [Link]
Once all the components and headers were soldered in, I attached my Arduino and configured it as an ISP. I then burned the bootloader for an Arduino Uno.
I then connected my FTDI programmer and uploaded the blink sketch.Success!
Wow, that LED is super bright! It’s actually blinding and kind of hard to look at. With that, I swapped out the resistor for a 1K one in order to bring the brightness down.
Knowing that the Atmega worked, it was time to solder in the rest of the components, except for the display. Again, I don’t want to come this far and then waste a $15 LCD.
LCD clock version 2 - [Link]
Markus Gritsch build another bedside table alarm clock, the schematic and source code is available here:
recently some vintage bubble displays popped up at various places , so I felt the urge to build another bedside table alarm clock, this time a really tiny one, roughly the size of an AAA battery.
Bubble display alarm clock - [Link]
VFD Moduar Clock IV-4 6-digit by akafugu.jp:
This new shield design for the VFD Modular Clock is a variant of the original IV-4 shield, but with 6 digits. IV-4 tubes are Russian 16-segment VFD tubes, and can display numerals and the letters A-Z.
We’ve also designed a completely new enclosure for the IV-4 6-digit shield. It uses 2mm semi-transparent blue acrylic, and is designed to give a low-profile rounded appearance.
Creating a 6-digit IV-4 shield without redesigning the base board presented a unique challenge: The HV5812 driver used to drive the VFD tubes has 20 channels. IV-4 tubes are 16 segment displays, 20 – 16 = 4, so in other words the HV5812 driver can only support 4 IV-4 tubes.
New Product – VFD Moduar Clock IV-4 6-digit - [Link]
Marcus Linderoth built a clock using a TI MSP430g2553 microcontroller and a HPDL-1414 display, that is available at Github:
After having ported Contiki to the Launchpad, I was eager on doing something with it. I built this simple clock with a vintage HPDL-1414 “smart four-character 16-segment alphanumeric” display and a msp430g2553.
Clock with retro display - [Link]