Introduction: Charlieplex 30 Led Bargraph

About: Dr James Moxham is a general medical practitioner in Blackwood, Australia. His interests include general family medicine, medical politics, microcontrollers and tending a rose garden. He lives on a property wi…

This project is a 30 led bargraph using 6 arduino pins. I'm using the display to indicate levels in tanks but it could be used for anything. Attached are the schematic, Eagle PCB files and a zip of the Gerber file ready to upload to a PCB manufacturer such as Seeed.

Step 1: Schematic

Schematic uses a standard Charlieplex design but with one small tweak - the leds are arranged so you can install just one 10 led bargraph, or two bargraphs for 20 leds, or three for 30 leds.

Step 2: PCB

This is the board design. It uses six resistors, three bargraph displays and a six way header. The writing on the side of the displays faces downwards (though if you did solder in the display the wrong way it would be possible to easily correct this in code).

Step 3: Files and PCB

The arduino code and zip of the PCB design are attached. If you go to Seeed, for instance, and upload the zip to their fusion PCB service, note the board size is their minimum of 5x10cm (the board is actually smaller than this).