ENGR2210        5 September 2012

Lab 1 - Pan and Tilt Unit

Due: 17 September 2012

Review

    By this point you should be comfortable with both reading and writing of digital signals, and reading from a simple analog sensor.  This lab will expose you to Servo motors, one of the easier ways to move things with your Arduino, and also employ the serial port to communicate with another computer (your laptop).

Background 

   The tripod in the image above holds a laser rangefinder mounted to a small pan-tilt unit.  The backpack strapped to the tripod contains batteries and a laptop for logging ranges measured by the rangefinder.  The pan, tilt and ranges are recorded to the laptop, and later processed to build 3D maps of the ice surface.

Description

  While I’d love for everybody to build a 3D laser scanner, LIDAR systems start at several thousand dollars and go way, way up from there.  In this lab, you will build a pan-tilt unit, capable of generating a hemispherical map of the brightness at a location.  You will first need to design a circuit for measuring the brightness from a photoresistor, and mechanically construct a simple pan-tilt unit.  You may also want some way to limit the field of view of your photoresistor.  You should transmit the pan, tilt, and brightness to an attached computer and log these numbers so that you can generate a plot such as this:

    The center of this plot is straight up; the angle on this polar plot is the pan angle, and the radius shows the tilt angle from straight up in degrees.

Deliverables

    Please hand in a lab report at the completion of this lab.  Your report should contain, at a minimum:

  1. A tidy schematic showing your final circuit, drawn in Fritzing if you’d like,
  2. A full listing of your commented source code,
  3. A short description of your process,
  4. A photo or two of your completed mechanical system, and
  5. At least one plot similar to the one presented in the description.

  You may choose to write this report as a traditional lab report, or in the form of a tutorial for posting on the web.  Paper, PDF, or a link to an HTML website are the only accepted formats.  Please don’t send .DOCX files.  They kill kittens.