This neat little circuit provides 8 LEDs directly driven from the PIC along with a single mode control switch. The firmware elsewhere on this page drives the LEDs with a 5 bit PWM signal providing each of the 8 LED channels with four levels of intensity; off, dim, mid, bright. A number of sequences are programmed into the firmware to provide some interesting visual effects and chase sequences, including the classic effect seen on the car in the Knight Rider TV series.
The design is deliberately simple with each LED being directly driven from a PIC I/O pin. This and the inclusion of an in-circuit programming header (ICSP) make the circuit ideal for teaching/learning introductory PIC assembly language programming.