Aurora 48 is capable of individually controlling 48 Full color LEDs using a 40 pin microcontroller. The principle of operation is based on my other “Aurora’s. (see Aurora 9×18)
The circuit is relatively simple and straightforward. If you’ve seen other LED matrix type circuit, this should look familiar.
In a nutshell, the 48 RGB LEDs are divided in two groups, connected in a 6:1 multiplex fashion, taking R, G, and B as bus lines, and common pin of each LED as column lines. There are two pairs of R/G/B buses. Since there are only 3 PWM outputs available on the controller used, I used a binary decoder IC to multiplex the PWM signal, to drive 6 bus lines. 3 pins are used to select one of the 6 buses, and 24 pins are used to control LEDs’ common pins.
The controller activates one bus at a time, outputs a pulse to the LED that should be lit. The actual duration that a particular LED turns on is controlled by the PWM pulse that goes into the binary decoder, 74HC238.
Read More: Aurora 48 – 48 RGB LED Sequencer