Many devices use multi-digit seven-segment LED indicators with dynamic indication. Usually they are connected to the ports of the microcontroller or to specialized driver ICs, such as the MAX7219.

This circuit is a bit of a departure from the rest of the content in this chapter, inasmuch as the appliance I describe here is not part of the E-2 project. The reason I have included this section is ...

Designed for front- or real-panel mounting, Wilbrect LEDCO’s just released bipolar LEDs work directly off a 120- or 240-V ac line as an LED power indictor or as a drop-in replacement for neon ...