Introduction: Charlieplex 30 Led Bargraph
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).