Slides –> MIDI

This week I focused on getting the slides to behave as I want on screen i.e. move smoothly, no glitches or jumpes, no delays.

Problems:

  1. The linear slides were acting like logarithmic slides (this took me almost the whole day to solve, the problem was the breadboard)

    How it should behave…
    Screen Shot 2563-04-03 at 10.00.15

    How it was behaving…
    Screen Shot 2563-04-03 at 10.01.53

    Once I realized the issue, I had a funeral for the breadboard
    IMG_9773.jpg

  2. It was so glitchy! All the values kept jumping

    EXPERIMENT 1: To solve this I tried the Kalman filter. However, the side effect of the filter is a ‘lag’ as the value jumps from one to the next because the filter tries to smoothen the values.
    (Change 100 to 127 to fit MIDI scale)Screen Shot 2563-04-07 at 18.18.55.png

    EXPERIMENT 2: Track the magnitude of change in the sensor value. If the change is greater than 2, count it as change, otherwise don’t. Since the steps of the digital slides were quite few (less than 127), this worked fine and the results of the movements were smooth.

    Screen Shot 2563-04-07 at 18.19.29.png

    EXPERIMENT 3: Although the movement transition between physical slide to digital slide is now smooth, sometimes when still, the slides are still glitching. This had to be a wiring effect so I built fitted box prototype of the slides to sit on.

    IMG_9785.jpg

    IMG_0116.JPG

    IMG_9783.jpg

So I got the desired movements in the end:

Next week: focus on the programming

Links to get started on:

IMG_9588.JPG

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s