How many Plasma lights can the Picade X HAT drive?

I’m considering a build that could potentially use more than 10 buttons, and the Plasma buttons are definitely pretty! Can the Picade X HAT drive more than 10 Plasma buttons, or is 10 it’s limit?


They are chainable and you can alter the number of ‘pixels’ in code. The limiting factor would be current, I’m not certain how many would be supported before brownout.

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Yeah it would be 3A minus what the Pi and picade use. Maybe 1A to play with? Probably slightly less than that. My best guess anyway.

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I’ve run 16 in series, but no more than that yet. You can mitigate the power problems you might get from trying to run more by just running them at a lower brightness.

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Thanks gadgetoid! I’ll keep that in mind for my build.

Any tips on adjusting the brightness of the plasma LEDS ?’

plasmactl does not seem to support setting the brightness, and hacking the code manually exceeds my python skills ;(

Has anyone managed to set the plasma brightness ?

Maybe look in /etc/systemd/system/plasma.service or /usr/bin/plasma

setting colours to somthing other than 255 reduces the brightness


plasmactl --colour 0 0 1

Sets all led to blue with minimum brightness.

I’m working on adding brightness control to Plasma/PlasmaCTL but it’ll require a fix to the library too. If you can figure out how to get stuff installed from the repo, the work-in-progress is here: Add brightness control for forum post 10985 by Gadgetoid · Pull Request #11 · pimoroni/plasma · GitHub