Sunday, August 24, 2014

Cheapest and Weakest Linear Actuator Prototype

I submitted my Shoji Pixels project (sites will be brocked until this December) to Japan Media Arts Festival . I can’t show the detail for now, but I found my old prototype in my vimeo library. Somebody may like this kind of thing, and I want to share it now again.

Linear Actuator for Depth TV using Arduino, TA7291p and Photo Interrupter

This module was intended for  “a cheapest and weakest linear actuator that extrudes a light-weight rod to 40cm away from the base”. 40cm is fairly long compared to usual industry-intended metalic linear acutators, but what I want to move was just a light-weight rod and my own RGB-LED module.

To do so, I milled a custom rotary encoder and used it with a photo interrupter mechanism (like in old mouse) and feed it back to a microcontroller to control the position of the rod.

In my current module, I am just using an open-loop structure to make the structure very simple, but making all the things from scratch drew me into this thrilling “Maker’s world”.

The following is how the controller looks like. The dataline was constructed with HC595 and after sending the motor-control signal, the input to HC595 is switched to the output of rotary encoder using some multiplexer/demultiplexer IC, and then the information was finally pushed back to the micro-controller through the same HC595 shift registors. This is very old-fashined circuit I think, but at least closed loop control worked very fine.

Control Module for My Cheapest and Weakest Linear Actuator

I don’t know if my work will be accepted, but if it will be accepted, I will maybe submit it to next year’s Ars Electronica.