The Ardunio Project

One of the projects I completed here in Taiwan was project using an ardunio processor to control a linear actuator. Basically I use the mouse on my computer to drive a motor, but more than that, I use a coupled LED and photocell  to map the position of a frame changed by the motor onto the coordinates of the mouse. Here's a diagram:

Using the ardunio to turn on the motor and reverse it's direction would be just a switch but the pair of an LED and a photocell provides a feedback mechanism to measure how close the LED is to the photocells. These measurements tell the program where the motor has moved the frame.

Here's the board:

The major components are:

The ardunio board with it's microprocessor

The H-bridge chip connected to the ardunio board that controls the direction of the motor.

The brush motor controlled by a PVM signal from the ardunio board

The feedback mechanism of two tubes with an LED movable at one end and an immovable photocell at the other end. The photocell signal is an input to an analog port on the ardunio board.

I can control the motor from the serial monitor on the ardunio board, but instead I wrote a GUI in the processing language to run on the PC that takes the inputs from the mouse to determine how the motor moves the frame position. It's a simple GUI,

Here's the set up for the movie, with the board next to the GUI, my hand on the mouse is off camera.

And here's the project in motion, I'm moving the mouse and clicking on a position for the motor to move the frame to.

This one worked out so well I thought I might investigate patenting it, but I thought: "Why ruin a fun project?"  Like Robert Cray said(and Seymour Cray would agree) "If you want to make my day, tell me a boat full of lawyers just sunk."

I reached the limit with what I could do here in Taiwan because the frame is now made from tongue depressors and Popsicle sticks. The holes are drilled with hand tools. In Seattle I will switch to plexiglass and a drill press. The web material on photocells say that the photocell is too inaccurate for applications. It works OK for me and I have a few tricks left to investigate.

Usually ardunio projects use an expensive stepper motor to effect position placement. I think my method could also work. The pieces I got off the web, putting them all together in this way was my idea. I give permission(if anyone cares) to anyone who wants to use it. Need help? Give me an email.

Eventually I would like to use two motors to move to any xy position. I'm thinking of using it for a microscope stage.