LED Matrix Abuse
439 views · Published 23 November 2016 · 4:29 · Indexed 3 October 2026
Channel: Jason Hotchkiss · 2016 · Science & Technology
I made this 8 x 24 LED matrix for a text display in a project - it is multiplexed by three 74hc595 shift registers on the columns and a tipc6b595 shift register on the rows. After noticing the interesting patterns I got from just touching the floating clock and data wires I decided to connect them to some simple oscillators and see what happened. A 74hc14 hex inverter is used to make the oscillators that clock the rows and columns. To get interesting data I use an 8 bit linear feedback shift register (another 74hc595 and an XOR gate IC) to get some "pseudo randomness". The LFSR output is made analog with a r-2r resistor DAC and an op-amp comparator compares it with a reference voltage I can adjust with a pot to change the dot density. The comparator output drives the data line to both the row and column shift regs. All 3 clocks (row and column shift clocks and LFSR clock) are adjustable by separate pots that I am twiddling during the clip. The raw oscillator outputs are mixed with resistors and fed to a little audio amp. I LOVE IT - I wanna make a bigger one now!
