Old Home The Chronulator SMD
The SMD version of the Chronulator.
The story.
Once upon a time a hardware/software guy named Jared Boone decided that we could read the
time in a different way. And that way was analog. But not the same old analog. His method involved
using “old fashioned” d'Arsenoval meters as clock displays. He originaly designed the
circuit to use a TI MSP430 µController but he redesigned it in 2008 to use an Atmel ATmega
AVR part. Both designs were/are open source. His company, ShareBrained Technology, provides
various kits and built-up versions 
of the circuit, and some appropriate
meters. The manual he wrote to aid his customers through the assembly steps is an excellent example
of how such manuals should be written, and the software, which is based on the Arduino
system, is cleanly written.
His customers have made some amazing clocks. Check out a few of them
on the Chronulator's main page ,
the Chronulator's gallery and on flikr .
I decided that the design was of sufficient interest to “SMD-ize.” I did so and
produced a couple of prototypes and have since got serious enough
about it to go into limited production.
There are only a few circuitry differences between this SMD version and the
ShareBrained DIP version, and none of them prevent the original software from working. See the schematic page 
for coverage of the differences.
Hackability.
Because the design is open, both hardware and software, the board is extremely hackable. The Arduino software has a very fast learning curve and the board's design brings out all the pins so they can be used for whatever interfaces you might want. Some potential examples are:
- use the Arduino IR remote control receiver library to make your clock settable using a remote!
- add various LEDs either as backlights or indicators
- combine the above ideas (with an IR LED) and use the clock to be the source of timed remote signals: perhaps use it to turn off audio and video sources to simulate occupancy when you are on vacation?
- Add a third meter to show seconds. This would require some substantial changes to the code and would likely increase the current drain enough that it would no longer be feasible to run from AA cells.
A very easily modified aspect of the system is that you can put whatever text and/or graphics you want onto the meter faces (a Klingon clock, anybody?—is there a Klingon alphabet anyway?).
Availabiliy.
I had supplied manufactured boards to Sharebrained so that they could be sold to their customers. Unfortunately they don't sell any version of any Chronulator right now. The main Chronulator page there says version 3.0 is in the works, but that has been the case for a while now.
As well, I supplied manufactured boards and meters to a local British Columbia web store,
BC-Robotics. Go to this page to have a
look at the store, but they too, are no longer listing them.
All three versions of the AVR Chronulator. The 4 in the middle are from the first ChronulatorSMD
production batch. Even though they have no programming headers they are loaded with the firmware
and have been checked.
The prototype, bottom right, is just a bit smaller. Of note is the double AA cell holder which
I prefer since a ChronulaterSMD can be hot-glued directly to it, making a very compact package.
Some further info.
- As required by the original license, the schematic, is
an open document, though I have gone further and made the Eagle files available too. (The
original board size was too long for the free version of Eagle to handle so these were not
initially made available, though they are now.)
- There are several other pages that document the Chronulator SMD (these can be found on
the expanded section of the menu, above):
- For owners of the board, the set up page , along with the
layout page , and the parts list serve as the main manual;
- A page about the software , and a bit more about the
serial commands, which are a part of the software;
- The design files page is a simple page with one zip file
link and one downloadable C file;
- And a general discussion about current sources in general and the Chronulator circuit in particular.
- For owners of the board, the set up page