[John Sarik] keeps cranking out new ideas for his digital Sudoku project. This time he’s using 7-segment displays for each digit. The game play works the same as the Nixie Tube version, but this makes things quite a bit easier to build. The board above is one of the nine modules that make up the game. They each use three shift registers to drive the nine 7-segment displays. With the help of five resistors all of the multiplexing is addressed via the serial input on those chips.
[Barry] didn’t want to deal with the voltages involved in using a Nixie display so he built this clock to look like it has Nixie tubes. He’s made 7-segment LED displays using some channel material, and mounted them so they look like they’re hovering above the clock base. Once everything was hooked up he added small glass jars over the top of each digit, completing the look.
[Vassilis Papanikolaou] just finished building a gear indicator for a motorcycle. This quite a simple implementation compared to some of the other vehicle information displays we’ve taken a look at. You should be able to build and install your own without breaking the bank. An ATtiny25 microcontroller reads data from a couple of hall effect sensors and the neutral switch, then displays the current gear on a 7-segment display.
There’s a magnet on the shifter and two hall effect sensors at the position for ‘gear up’ and ‘gear down’ shifting. The AVR chip keeps track of these and even stores the last position in EEPROM when you shut the bike off. If the device somehow gets off track, it will automatically recalibrate itself next time you shift into neutral, thanks to the bike’s neutral sensor switch.
A rudimentary understanding of digital logic and simple integrated circuits is critical if you’re ever going to pull off some really gnarly hacks. [Daniel] put together an explanation about the use of 4511 BCD 7-segment drivers. These chips take binary data in and output decimal data to a 7-segment LED display. In short, they can read 0b1001 from input pins and light the numeral ‘9’ on the display. The best part is that you can build this example circuit in the Atanua logic simulator without ordering parts. We love zero-cost learning!
We’ve seen several creative projects from [Sprite_tm] and this one sets a new bar. He got his hands on some paint that changes color with temperature. By covering a circuit board with the paint then heating the circuits he’s created a heat actuated 7-segment display (his post is in Dutch). Three seconds at about 1 amp is enough to turn the black paint white. When the segment has been disconnected for about one minute the paint fades back to black. Now that we’ve seen his concept, leave a comment and tell us how you’d use it.
[Markus] noticed a lack of 7 segment LED displays that could show RGB. Like any hacker, he sought to remedy this. The solution he came up with was to basically remove all the electronics from the plastic body of the display. He then mounted new surface mount RGB LEDs in the correct places. This may be a bit messy, and definitely increased the footprint in this layout, but as you can see from the pictures on his site, the final result is quite nice. What uses can you think of for these?
