It's kind of amusing that most desktop PCs have external I²C connectors which can be used to access (read/write) arbitrary I²C devices.
By which I mean the DDC pins on the DVI, HDMI, or VGA connectors.
Linux conveniently exposes the DDC pins to userspace using the generic I²C device interface, and they work with normal I²C utilities.
fuchsiaaaaaaaaaaaaaaaaa
@kepstin wonder if you could write a neopixel / APA102 driver using that to drive your DIY gamer leds
@f0x looks like that's a "no" on both - neither are I²C devices. NeoPixels use a single-wire connection protocol, and the APA102 is SPI.
@f0x hmm. If the device is compatible with an open-drain 5V connection, then theoretically you probably could hook up the single-wire interface to the I²C clock pin, and then manually time the clock in software.
FWIW, On many embedded controllers, the "I²C" pins can actually be reconfigured as generic GPIO pins to drive other protocols.