Building and Wiring the LED Sign - Electronic Project Sep 25, 2012The following wiring diagram shows the wiring for the letter "P" which is made of 29 LEDs. 7 sets of four LEDs each and one set of one LED is used to make up the 29 LEDs of the letter "P". Below this wiring diagram for the letter "P" is a diagram that shows the value of resistors needed for 4 LEDs, 3 LEDs and 1 LED. Wiring LEDs Correctly: Series & Parallel Circuits Explained! Hopefully those looking for practical information on electrical circuits and wiring LED components found this guide first. It’s likely though, you’ve already read the Wikipedia page about Series and parallel circuits here, maybe a few other Google search results on the subject and are still unclear or wanting more specific information as it pertains to LEDs.