Tag Archives: multiplexing

Charming 8x8x8 RGB LED cube

Check out this another 8x8x8 RGB LED cube controlled by Arduino. The 512 RGB LEDs are driven by 25 74HC595 shift registers using multiplexing.

8x8x8 RGB LED cube

8x8x8 RGB LED cube

For those unfamiliar with LED cubes, they are simply a 3-dimensional array of LEDs that make for interesting displays. My project here is not the first RGB LED cube, nor is it the best, but I am documenting my process because while designing this cube I appreciated every resource on 8x8x8 RGB LED cubes I could find. My goals for this project were to create an 8x8x8 multicolor (RGB) LED cube cleanly. That is, with all the electronics contained neatly. Additionally, I wanted to use Arduino code to make it more accessible to others and for ease in upgrading. More on this later though.

The hardest challenge was in making the LED frame straight and square. As with most things, quality depends on how much time you put into it. If I were to redo this project that would be the step I spend the most time trying to get right. Overall the project was rewarding in the end and I would say don’t be intimidated by the amount of work needed for design and assembly.


Three tact switches, three LEDs, three I/O lines

Francois AUGER & Philippe Fretaud has posted this Design Idea on EDN that shows how to drive three LEDs and scan three tact switches with only three I/O pins of microcontroller. They have demonstrated the technique using the Atmel microcontroller (Arduino), and the technique could be useful for any low pin count devices where you can run out of I/O resources easily.

3 switches and 3 LEDs to 3 I/O pins

3 switches and 3 LEDs to 3 I/O pins

Lab 11: Multiplexing seven segment LED displays

In Lab 6, we discussed about interfacing a seven segment LED display to a PIC microcontroller. The seven segments were driven individually through separate I/O pins of the microcontroller. If we do just like that then for 4 seven segment LED displays, 28 I/O pins will be required, which is quite a bit of resources and is not affordable by mid-range PIC microcontrollers. That’s why a multiplexing technique is used for driving multiple seven segment displays. This tutorial shows how to multiplex 4 common anode type seven segment LED displays with a PIC16F628A microcontroller.

Multiplexing 4 common anode seven segment LED displays

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