Sunday, March 27, 2011

Weekend in Paris...

I wish.

This was another well spent weekend, inside, soldering. Lots of soldering, mostly LEDs.
I never built a LED matrix myself from discrete LEDs. (I actually started one for the "Word clock" on, but never finished it.) I always took "for granted" (not literally; I paid for them) the 8x8 LED matrices or the LED displays from Sure Electronics. But this weekend I truly understood why the German-made (?) QlockTWO is as expensive as it is. Not only because of the design but also because of the amount of labor involved.

To cut through the chase, I started assembling the ClockTHREE. It's got 160 RGB LEDs organized in a matrix of 16x10. For those not familiar, ClockTHREE is an initiative by Justin and Anool to develop a better (multicolor, programmable) and open-source version of the above-mentioned QlockTWO.

This is how it looks so far (not finished yet, still waiting for a few components to arrive).

A few first impressions on the hardware:
  • This is not your average project. Even though it may look like the "LOL shield" from a distance :), it is more than just soldering LEDs. Each RGB LED requires a bit of preparation (with the special wedge tool), then careful insertion and double checking with the multimeter. It is absolutely necessary to read the assembly instructions before starting soldering the LEDs.
  • The PCB, one of the biggest I have seen offered in a kit, looks very professional. It's nice to see the component values (for example, "10K" for resistor) in the silkscreen. The layout is very well balanced, with parts placed around the LED matrix display area, buttons and connectors accessible at the bottom.
  • There are a couple of surface-mounted ICs (the shift registers), which would require non-novice soldering skills. Note (from Justin): the actual kit will come with the SMDs pre-soldered on breakouts, which will allow for easy removal in case of testing/debugging.
  • The rtcBOB, compatible with the ChronoDot, could be used in other projects as well, since it is removable (and connected through headers).
As shown in the photo, the board is missing the last two rows of LEDs. They will be populated with single color 10mm white (or blue) LEDs.