Pupil and maker Reid Sox-Harris has constructed a Easy Add-On for badge homeowners who like a little bit of color-mixing — however his Metamer SAO goes fairly a way past pink, inexperienced, and blue, to ship what he describes as “RRAYLLGTTBB+UV+WWCWBWDW” mixing.
“A[n] SAO with all of the LEDs to elucidate how metamerism works,” Sox-Harris explains of his creation. “As an alternative of straightforward RGB coloration mixing, this factor can mix-n-match 16 distinctive spectra to make that good coloration you have been on the lookout for. [It has] 12 distinctive wavelengths of LED + 4 temperatures of white [and] features a actually cool 496nm LED which is a coloration coming from an LED you have in all probability by no means seen earlier than.”
In case you’re bored with RGB coloration mixing, this badge add-on delivers “RRAYLLGTTBB+UV+WWCWBWDW”. (📷: Reid Sox-Harris)
The idea behind the badge is, as Sox-Harris says, metamerism — matching colors of various spectral energy distributions primarily based on their notion, creating metameric matches that are not a real match however look shut sufficient to the human eye. “I do a good bit of theatrical lighting, the place coloration is a big a part of any design,” Sox-Harris explains of his pondering behind the venture.
“Extra LEDs provides a smoother gamut, higher consultant of what a tungsten supply with filters would possibly output. For instance, ETC’s new top-of-the-line LED fixtures makes use of 8 LEDs together with an thrilling new deep pink for higher pores and skin tones. It is with that in thoughts that I designed this board: I wished to display all of the alternative ways LEDs might work collectively to create mild, and the way our eyes play methods on us on a regular basis!”
The result’s a badge add-on that has 16 particular person LEDs, each considered one of which covers a distinct wavelength — starting from 456nm ultraviolet via to 640nm deep pink, plus 4 totally different temperatures of white from 3,000 Kelvin heat white as much as 11,000 Kelvin daylight. They’re all related to a Texas Devices LP5018 LED driver, which is managed by way of the badge’s I2C bus. The thought: the flexibility to combine colours to seek out your personal metameric matches, although in the meanwhile Sox-Harris admits it is restricted to “turning on and searching fairly.”
The present model of the SAO requires enter from a badge, however a V2 contains an on-board microcontroller. (📷: Reid Sox-Harris)
After proving the idea with an preliminary design, Sox-Harris is now engaged on a second revision — which introduces a standalone mode, pushed by a low-cost Puya PY32 as per Jay Carlson’s suggestion. “[It] will probably be programmed to initialize the LED driver on power-up in order that the SAO will really show one thing, even on a default badge with out customized firmware,” Sox-Harris explains. “Plus, down the road I can maybe offload animations and such to this MCU as an alternative of doing it on the badge itself.”
Extra info on the venture’s origins is obtainable on Sox-Harris’ web site, with schematics, fabrication information, and supply code on GitHub underneath the permissive MIT license. Extra particulars on the second-generation model may be discovered on Hackaday.io.
