rupertdaily celebrated his birthday yesterday evening, so I wanted to make a LED clock for him -- I had never gotten around to do so before. Since anodised aluminium and blue LEDs are 'geek chique', it wasn't hard to decide what to make.
I am very pleased with the end result (apart from a few minor details that aren't immediately apparent anyway) -- I think it is the most beautiful physical object I have every created (so far!).
The front. I made good use of the laser targetting on the new drill press -- the lines are ever so slightly wobbly, but it isn't too obvious at first glance.
I used the 5mm low-profile LEDs -- these have a viewing angle of 120 degrees, which is nice when it's a clock. An added bonus is that the light isn't focussed in a single beam as with the high-powered LEDs with the smaller viewing angle, making it less of a spotlight. Just ask shironuchan and babarage how much light those other LEDs give off!
A side view. The clock is made out of a single sheet of aluminium, bent into shape. This means that the electronics are exposed -- a touch that I quite like. With people buying shiny boxes that exhibit all sorts of complex behaviour, technology (and electronics in particular) take on a mystical aura. Not with this clock: if you want to see how it works, you just have to look at the back of the clock.
A close up of the LED-board. The LED clock uses bare wire connections on the front (basically wires from a LED bent and soldered). Normally, with wooden housings, I just stick the LED board stright to the material, but that would obviously not work well with a conductive material like aluminium. So I had to 'insulate' the board from the metal. I used underlayment for wooden floors for this: it's reasonably thick which gives me quite a bit of room to work with.
Unfortunately, this also meant that I could not solder the LEDs as close to the board as possible. So I had to use the underlayment as a stand-of, wriggle the LEDs in place and then solder them. This went not as well as I had wanted: the board has to be placed at an angle, because I could not get the board straight on to the alu when soldering.
A view from the back. You can see that the LED board and the front plate aren't running parallel.
A close-up of the controller board. Again, a PIC 16F628A drives the whole clock. Towards the top are the six transistors that drive the columns of the LED board. Again, underlayment isolates the board from the metal.
A close up of the two buttons to set the time, and the power connector. It took quite a bit of wriggling to get the controller board in place after placing the buttons -- future versions will have more room for the controller board, so that the electronics are more visible.
To top it off, a front view with a few more LEDs lit up.