Sometimes you need to display a number nice and large, making it easily readable at a good distance. [Lewis] has just the thing for that: a big expandable 7-segment display.
The build is modular, allowing it to be extended from 2 to 10 digits and beyond. The digits themselves are made of 3D-printed parts assembled onto acrylic. These can then be ganged up in a wooden frame for displaying larger numbers with more digits. Individual elements are lit by addressable LEDs, and the project can be built using an Arduino Nano or an ESP8266 for control. The latter opens up possibilities for controlling the screen over WiFi, which could prove useful.
[Lewis] has built his own version for a local swim club, where it will be used as a laptimer. Other applications could be as a scoreboard in various sports, or to confuse your neighbours by displaying random numbers in your front yard.
We’ve seen a similar build from [Ivan Miranda] that served well as a workshop clock, too. Video after the break.
I see a back-ground and I want to paint it bla-aack (with apologies to the Stones)
The Animals performed the song at the Monterey Pop Festival.
I agree. The white background seems to make for a low contrast to the illuminated segments, with the unlit ones too contrasty.
Yet the unlit segments on the displays shown in the corny examples are lower contrast, presumably just made-up graphics rather than photos of the actual completed displays?
I used dark gray for Sizable7 (https://sizable7.nickstick.nl). Experimented with several colors and materials. The one I choose gave the best contrast I think.
Or to Vanessa Carlton, who does brilliant cover! (better than the original IMVHO 😁)
Black or dark grey.
I got into an argument with my senior years ago on a church organ installation where the speakers had to be covered in white grill cloth, the whole place was white. He painted the wood face of the speakers white in the shop and then at the church he put the cloth on and black circles show up through the pristine whiteness. Guess what he did next. It involved white paint. You can’t paint a shadow! Circles still showed up.
When I found out, ooh. I told him if it’s all dark besides the cones are set back, there is minimal contrast. I had to show him. Paint it black and when covered in white scrim it looks white enough and has no pattern showing through. Same principal here.
Get diffusing plastic from any cracked flat panel TV, or use the whole TV gutted and make a big clock etc. Portable with the low stand they have.
This is a great help. My plans are to have a sign on our residential street where many race up to 2 x the 25 mph speed limit to show the cars their speed.