So I have the Arduino controlling both the shutter for the Canon camera I’m planning on using as well as a string of LEDs. This will provide both lighting for the slide backlight as well as for the side-lighting for the mounts.

All I have to do is hit ‘c’ on the computer (as it stands right now) and it’ll sequence the lights on and take a picture.

This will have to be extended a bit to control the backlight and the mount lights separately, likely with another command to handle that.

The big thing with this experiment is verifying that I can control the W2812B lights using a 3.3V Arduino despite the fact that the LEDs are running at 5V. The answer is: yes. To complete the circuit I connected up the grounds to each other.

So the Arduino is powered from my laptop, and the LED lights are getting their mildly perturbed pixies (only 5V) from the power supply on the bench. And it all works as expected.