Making large numeric displays

This reminds me of something I did some years back. I am somewhat myopic (4.5 diopters or so). I wanted a clock I could read from across the room, without my glasses, for my bedroom (so I could read the time upon waking up without having to find my glasses). Initially I would just roll over and haul the bedside clock up next to my face - but then when I met by now-ex and found myself no longer sleeping alone, there was sometimes someone between me and the clock. The largest stock clock I could find had digits only 1.8" high, I think it was. I picked up one of those and found that, as I'd hoped, the display was on a separate board, with wires forming a kind of coarse ribbon cable between that and the main clock board. I cut the wires and probed the display part with power and a resistor suitable for LEDs, to determine the pinout. Then I cut a piece of 1/8" plywood to the size I wanted the clock face to have (something like 8" by 24" - I'd have to go measure to be sure). Then I laid out (digitally) and printed out (piecemeal, on multiple sheets, with registration marks) a clock display 88:88 made up of five LEDs per segment. Using those sheets as a guide, I drilled out the plywood to take round LEDs at the right places. Pushed the LEDs through, soldered them up appropriately, and all that was left was to build the rest of the case and wire up connectors (I used DB25s) to the display and the clock board. I now have a nice wooden clock on my wall, with the electronics board from the original tucked in one corner driving nice big 7-stroke digits. I tried to interpose additional electronics between the clock and the LEDs, because the LED brightness was so variable I could only assume I was near the limit of the clock's drive capability (driving five LEDs instead of the two or so it was designed for - 7.5V drop instead of about 3V). I never managed to make it work; it appears that power-line AC direct from the power transformer is used to drive the two common poles (I forget whether they were wired common cathode or common anode), and that made it difficult to get the switching to behave - I don't totally understand the problems; I punted to driving the LEDs directly and accepting the brightness variations rather than putting the time and effort necessary into figuring out what was causing it. This is different from what you're doing in some rather significant ways, such as being pure 7-stroke instead of the more rounded digits you're looking for, but perhaps the experience can help. I would actually prefer to sand it (or sandblast, or whatever) to a matte finish instead of a smooth finish, for better light diffusion - the same reason they frost light bulbs, basically. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B