Microcontrollers in LED Displays

In the old days, designers relied on incandescent light bulbs for complex display applications. Some older programmable displays incorporated the light bulbs into a pixel based display system. To yield a pattern on the display, each bulb must be connected to a central controller. One central controller would require an output pin for each pixel within the display. This means a display with one thousand pixels requires one thousand output pins form a single chip, or fewer pins with a system of supporting multiplexers. A microcontroller network still requires one pin per pixel, but only one output pin per microcontroller. This alternative relies on a single microcontroller per pixel, within the display. Each controller communicates with other controllers within the display, sending critical information about display rendering over a data bus. Advances in modern controllers allow for more computing power within a single chip. Modern microcontrollers, such as the PIC10F200 by Microchip, work perfect for LED display applications that rely on such network configruations. The reduced size and cost now make a microcontroller network a possibility. Yet another advantage of the network includes reduced wiring. Rather than thousands of wires leading back to the main controller, the system requires as few as four conductors; power, ground, data and clock. A master controller may be designated to relay data to each slave microcontroller, allowing for the media to be properly displayed.