W11: Output Devices

For this assignment I use the Hello Fab Kit board I designed and produced for the Electronics Design assignment, in turn based on the work done in the Electronics Production assignment.

Initial explorations

LEDs

One of the first things I tried is running the classic "Blink" Arduino sketch on an external LED.

I also needed to test out neopixel support with the Hello Fab Kit. This served as a proof of concept.

Sure enough it worked alright with a strip I had laying around:

I also tried an single neopixel integrated in the control panel, in this case just randomizing its color.

Step motor

It was also clear I'd need a motor sooner or later for the project, so I gave a step motor a go. It was easy to control, but it ended up lacking torque and speed for my use case.

Output devices for the final project

LEDs

In the following example we can see a single neopixel integrated in the control panel, which serves as reference for the colour of the strip of pixels in the spinning ring.

I also experimented with using the potentiometer to control the brightness of neopixels inside the box, but it turned out to be impractical, as the useful range for long exposure photography is very limited anyway (around 5% brightness).

I ended up using the potentiometer to move a single pixel throughout the strip, which created a way more useful effect in the photographs.

Servo motor

As mentioned previously, the step motor didn't work out for the project. I was lucky to have a servo motor laying around. Notice in the following example how its rest state is actually moving slowly. This had to ba calibrated later on to 95º instead of 90ª.

In the following video we can see the servo motor integrated with a push button control.