Lumiknob—Bring Your Embedded Projects to Life with Rotary LE

Bringing Lumiknob to Life

What is Lumiknob?

Lumiknob is a simple but powerful module that connects the analog world to digital displays. By turning a single potentiometer, you can control a series of up to 32 LEDs, thanks to the popular MAX7219 driver chip. With Lumiknob, creating intuitive rotary controls with bright, real-time visual feedback is easy—no complex programming or hardware hacking required.

Why Did We Build Lumiknob?

As hardware creators and designers developing new technology, we noticed a gap between analog input (like potentiometers) and dynamic digital output (such as LED arrays). While there are plenty of ways to read analog signals or control LEDs separately, we wanted a plug-and-play module that brings both elements together seamlessly. Our aim was to make it easier for makers, engineers, and product developers to visualize analog signals, experiment with user interface ideas, and build interactive hardware projects—all with a single, streamlined solution.utput (like LED arrays). While there are plenty of ways to use potentiometers or light up LEDs, we wanted a plug-and-play module that combines both, making it easier for makers, students, and engineers to visualize analog signals, experiment with user interfaces, and build interactive projects.

Lumiknob was designed to:

Accelerate prototyping for rotary or slider-based UI concepAccelerate prototyping for rotary or slider-based UI concepts

How Does Lumiknob Work?

Lumiknob integrates a standard potentiometer with the MAX7219, a well-known LED driver that communicates over SPI. Here’s how it works:

• Turn the Knob: As you rotate the potentiometer, your microcontroller reads its analog value.
• LED Sequencing: This value is used to control which of the 32 LEDs are illuminated, how fast they animate, or what pattern is displayed.
• SPI Communication: The microcontroller sends commands to the MAX7219 over SPI, instantly updating the LED array.

This setup only requires a few connections:

• The potentiometer connects to an analog input pin.

• The MAX7219 connects to the SPI pins (MOSI, SCK, CS) of your microcontroller.

See Lumiknob in Action!