UNDER DEVELOPMENT More info - Controller
More info - Relay boards
More info - Sequencing software More info - Countdown clock
More info - Wiring / Power
More info - Mounting
More info - Videos
The countdown clock started life as an idea over coffee one morning in January, when I asked "What can I do for this year?" I'd already established that I was going to build a computer controller, and one of my work colleagues suggested that I make a countdown clock, to count down the number of days (sleeps) to Christmas. I thought that was a great idea, and ideas rolled around my head while I was building the controller, until I starting serious work on planning it in August.
I bought 8 boxes of Christmas lights with 150 lights each. The plan was to use 75 lights per segment, have 75 lights for the words "Sleeps to go" and then use another 75 lights to write the words "Tune to FM 107.7" - this is the frequency I'd be broadcasting the music on. My wife later convinced me not the clutter it up with the "Tune to FM 107.7" so I still have a spare relay, and just under 75 spare lights.
I bought a piece of MDF 90cm x 180cm, and marked out the grid for the holes for the lights. Each segment is has 75 lights, each digit has 7 segments - that's 1,050 holes (excluding the words!).
I started drilling, and managed to blunt 2 drill bits (and was well on the way to blunting the third) by the time I finished. I framed it up with 50x12mm pine, and then painted it front and back with gloss black paint, and redrilled most of the holes once the paint had dried.
The began the task of splitting the light strings into halves (5 x strings of 15 lights), and inserting and glueing them into the holes... that was a mamoth task, and when you start to ask the question "was this really such a good idea?"
Above: My daughter Rachael helps out - inserting and hot-glueing lights in place.
Below - Finished!!! All wired up (rear view), and front view. (Click to enlarge)
Last was the controller. The power supplies for the lights are wired to a relay board, and I added manual over-ride switches, so that I could manually set the clock (on the off chance that the relays and controller software didn't work to plan.
The power supplies / controller connet to the board with 4 x 7-pin DINs, which control the two seven segment digits. The words "Sleeps to go!" are controlled by a separate lead.
When testing with the controller, I came up with a quick sequence, but didn't have time to fully program up anything for this year's display (so I manually set the number displayed each day).
Plan for next year is to have the program automatically calculate the number of sleeps to go, and controll it without any manual intervention.
