The subject of our latest kit review is the “Epoch Clock” from Maniacal Labs, a new organisation started by three young lads with some interesting ideas. Regular readers will know we love a clock – so when the opportunity came to review this one, we couldn’t say no.
At this point you may be thinking “what is Epoch time anyway?”. Good question! It is the number of seconds elapsed since the first of January, 1970 (UTC) – and used by Unix-based computers as the start of their time universe. (For more on the theory of Epoch time, check out Wikipedia). For example – 1379226077 Epoch time is Sun, 15 Sep 2013 06:21:17 GMT. That’s a lot of seconds. If you’re curious, you can do more calculations with the EpochTime website.
Moving forward, this clock kit will show Epoch time in full 32-bit binary glory, using a DS1307 real-time clock IC (with backup battery) and is controlled with an ATmega328P-PU – so you can modify the code easily with the Arduino IDE or WinAVR (etc).
The creators have spent a lot of time on not only the packaging and out-of-box-experience, but also the documentation and setup guide – so as long as you’re fine with simple through-hole soldering the kit will not present any challenges. The kit arrives in a sturdy box:
… with well packaged components. Everything is included for the finished product, as well as IC sockets, the RTC backup battery and a USB cable so you can power the clock from a USB hub:
The PCB is a good thickness, and has a clear silk-screen and solder mask:
Construction is simple, just follow the step-by-step instructions. Starting with the USB socket for power:
… then the resistors:
… the LEDs:
… all 32 of them. Note that the LEDs don’t sit flush with the PCB, so a little effort is required to keep them aligned:
Then the rest of the components just fit as expected. I’ve also added the included header pins for an FTDI programming cable and ICSP to keep my options open:
Then simply fit the battery, insert the ICs and you’re done:
Using the clock
The microcontroller is pre-programmed, so you can use the clock straight away. You will however need to set the time first. To make this incredibly easy, there is a special web page that displays the current time and Epoch time, which steps you through the process of setting the time using the buttons.
Or with some code available on the kit github page and a programming cable, you can automatically sync it to the clock. Once setup, the battery will keep the current time in the RTC nicely. The clock is powered by 5V, which is easily supplied with the included USB cable, or you can always hack in your own feed.
So what does Epoch time in 32-bit binary look like? Here’s a short video of the clock in action:
Reading the time requires converting the binary number displayed with the LEDs back to a decimal number – which is of course the Epoch count of seconds since 1/1/1970. Math teachers will love this thing.
But wait, there’s more!
If you get tired of the blinking, there’s a test function which is enabled by holding down both buttons for a second, which turns the Epoch Clock into a nifty Larson Scanner:
To create your own sketches or examine the design files in more detail, it’s all on the clock github page. From a hardware perspective you have an ATmega328P-PU development board with a DS1307 battery-backed real-time clock – with 32 LEDs. So you could also create your own kind of clock or other multi-LED blinking project without too much effort. Review the EpochClockSchematic (.pdf) to examine this in more detail.
I really enjoyed this kit – it was easy to assemble, I learned something new and frankly the blinking LEDs can be quite soothing. The clock would make a great for a conversation-starter in the office, or would make an ideal gift for any Sheldon Cooper-types you might be associated with. Or have competitions to see who can convert the display to normal time. After shots.
Nevertheless it’s a fun and imaginative piece of kit, fully Open Hardware-compliant – and if you’ve made it this far – get some and have fun. Full-sized images are on flickr. Interested in Arduino? Check out my new book “Arduino Workshop” from No Starch Press.
In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other – and we can all learn something.
[Note – The kit reviewed was a promotional consideration from Maniacal Labs]
[original story: Tronixstuff]