One of my first successes with Cypress semiconductor was the work I did with a digital sign maker in Texas. The types of signs they designed and built are the roadside dot matrix signs.
The PSoC module
Cypress had a product called PSoC ( Programmable System on a Chip). The PSoC was a small micro controller with configurable I/O which in this case was used for ultra bright LED driving and a serial interface for module to controller communication. The module drove a small matrix of LEDs. These modules would be connected together to form one large display panel.
The sign comprising PSoC modules
This is the back view of a completed display module. The PSoC modules are connected via serial interfaces to a PC card, that handles the graphics and communications requirements of the sign. The signs could be permanently mounted or portable mounted on a trailer (as seen below)
The completed Item
The completed item shown is one of the first trailer mounted signs.