I plan to work out how to precisely control the very cheapest (60-ishUSD) laser galvos.
Previously, I used a set of these galvos in a clock project. The clock's face, despite being defined with straight lines, ended up with curves. I like the curves on the clock, but I reckon that I could get much more out of these galvos.
The aim here is to be able to control a cheap laser galvo to produce laser shows effects such as drawing complex figures. To do this, I plan to characterize one set of galvos, to understand what affects the position of the laser beam and thus how to control the inputs to produce the desired output.
I plan to do this by commanding both the mirrors and the laser and capturing the resulting picture with a camera. Let's say we scan the x-axis mirror from left to right, starting from t=0. This will move the dot across the projection screen from left to right. We can then find the x-axis position at time t=1 and time t=2 by turning the laser on between t=1 and t=2 (red section in diagram below) and using a camera to capture the resulting drawn line.
I'm pretty sure I can capture this accurately with an RPi camera