This seven segment art display makes use of a 81 seven segment red common cathode LED displays. The LEDs are arranged onto 100x100mm boards that each contain an Arduino Nano and 9 seven segment displays, daisy chained through three-pin headers located on the sides of the boards. The pins (power, ground, and serial) provide the signals necessary for propagating a program across each of the connected boards.
The first board – with two Arduino Nanos – sends instructions for which digits to light and drives the display, sending the instructions over to the next board on the chain.
In a multiplexed arrangement, a single Arduino Nano is able to drive up to 12 seven segment displays, but only 9 needed to be driven for the program, keeping D13’s built in LED and the serial pins free. Since no resistors are featured on the boards, current limiting is done through software. This was inspired by the Bubble LED displays on the Sinclair Scientific Calculator, and was done in order to achieve a greater brightness by controlling the current through the duty cycle.
The time between digits lighting up is 2ms, giving them some time to cool down. The animations in the demos featured falling and incrementing digits, as well as a random number generator using a linear feedback shift register.
When I first saw the screenshot, I thought it was going to be some variation of Conway’s game of life, but done on a giant array of 7 segment displays. Still entertaining, from the art perspective.
And I thought it was going to be pi to 80 decimal places.
First few seconds of video, I’m thinking “Sudoku Tetris”.
Now my brain hurts.
Finally! A way to show the US National Debt!
B^)
The numbers are dropping. That’d be the wrong visual.
B^)
Next challenge: 14 or 16 segment LED for full alphabet Matrix style!
Previous hackaday articles on having tons of seven-segment displays: 2012 2013 2017