RGB gamma and other compensations

geekscape / aiko_engine_mp

microPython event based engine supporting network messages (MQTT), times and various hardware drivers

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RGB gamma and other compensations #39

Open garthk opened 3 years ago

garthk commented 3 years ago

@marcmerlin, the gamma adjustment code in #38 helped get the orange right but it strikes me:

The blue is too dim, which I'm guessing is just these pixels not being that great
The green is too bright, which might instead be the human retina
The gamma might not match my pixels because I just grabbed someone else's table
The ESP32 might be strong enough to generate its own tables at boot time off configured gamma and LED strength adjustments
It'd be nuts to keep all that to just one plugin when it could be in aiko.led so everyone could get their colours right first try

Got any links handy I can follow to learn more? I'm happy writing the code up. :)

marcmerlin commented 3 years ago

honestly, I'll leave this to andy. I care about colors when I have 2D matrices, but for a strip around my neck, I really don't care :)

garthk commented 3 years ago

The blue is fine on the long strip with dedicated power, so I think the problem there might have been running it off 3.3V. This might then not be worth any effort unless it helps keep the colours straight despite dimming.

marcmerlin commented 3 years ago

oooh, right, they are being undervolted, so they probably do not give the correct color, good point. This brings us back to https://spectrum.chat/lca2021-swagbadge/hardware/on-the-mythical-5v-rail~0827bdfe-d608-4021-b04c-b0d260ffa833

We really should find a way (if possible) to get Vcc out of that chip

garthk commented 2 years ago

Looping back: I rigged my badge to drive a strip in my Xmas tree. Mixed colours proved so difficult to get reasonable I'm going to rig up an RGB sensor eg. this TCS34725 module knock-off I've got lying around, crunch numbers, and see if I can come up with a convenient compensation system.