SparkFun's Qwiic Visible Spectrum Emitter Aims to Cover Everything Bar Infrared and Ultraviolet
Built around TI's LP55231 LED controller, this nine-LED board offers a lot more than just red, green, and blue.
SparkFun has launched a new SparkX board design, and this one's for anyone who finds RGB LEDs too limiting in terms of color reproduction: the SparkX Qwiic Visible Spectrum Emitter.
"The Qwiic Visible Spectrum Emitter combines nine discrete LEDs spanning the visible spectrum from 455 to 720nm," explains SparkFun's Chris McCarty of the new board design. "Each LED emits light with a narrow peak wavelength, with one exception made for the phosphor-based green LED in the middle of the spectrum. We compromised on green so that all of the LEDs would be in the same luminous intensity ballpark without breaking the bank."
While it's possible to mix various colors from red, green, and blue with a single RGB LED, the Visible Spectrum Emitter — as it name implies — aims to cover the entire visible spectrum, stopping only at infrared and ultraviolet. Drawing on Ben Krasnow's MultiSpecLED design, though using lower-power LEDs, the board is built around the Texas Instruments LP55231 LED controller — accessible through handy solder-free Qwiic ports, as well as unpopulated 0.1" (2.54mm) pin headers.
"A USB-C port on the board allows you to connect a high-current 5V power supply for the LEDs and the exposed copper on the back is sized to accommodate our self-adhesive copper heatsink for applications where you might need active cooling," McCarty adds. "The LEDs can be run to about 80 per cent PWM cycle without the need for an auxiliary heatsink or active cooling, but any higher than that and the board will warm up FAST."
Those looking to build around the Qwiic Visible Spectrum Emitter, though, need to be aware that it's not a mainstream SparkFun product but a SparkX "experimental product" — as denoted by its black, rather than red, PCB. That means less technical support, though SparkFun has published example code as part of its LP55231 Arduino library, and that when initial stocks are sold out there's no guarantee of a second production run.
The Qwiic Visible Spectrum Emitter is now available on the SparkFun store for $39.95, while stocks last.