Take a gander at the Giant LED bar graph which ... while a couple of transistor ICs controlled by 595 shift registers address them on the low side. ... but in this case it’s an Arduino.

Each bar-graph display comprises one red and one blue LED in the same bar (Figure 2). Each LED has its own anode and cathode connections, thereby keeping this circuit simple without the need to add ...

Posted in LED Hacks Tagged 595, bar graph, led, shift register, transistor array Ultrasonic Rangefinder As Scanning Radar October 10, 2011 by Mike Szczys 14 Comments ...

The LED segments of the display require current-limiting resistors when powered from a 5 V logic pin. The value of the resistor is typically between 330 and 470 ohms. And, driver transistors are ...