7.1 Final Objectives

One of the final objectives of this project is a piece of code that works for practically all differentially steered robots using stepper motors. To make your program easier to debug without robots, it must product suitable output to standard output (stdout) so that you can use another program to analyze the output.

The following describes the output of your program:

• Any text on a line after a pound (#) symbol is ignored, use this for commenting (and debugging).
• An event is recorded on one line. A motor performing a step is an event. Two events at the same exact time takes two lines.
• Time is measured in ticks. Use an unsigned long integer (32-bit) to count ticks.
• Each line begins with a tick count, expressed as a decimal unsigned number. Use a space character to separate fields.
• Use the letter ``L'' (uppercase) to indicate a step of the left motor.
• Use the letter ``R'' (uppercase) to indicate a step of the right motor.
• Although your program doesn't need to know the physical characteristics of the robot, it may be helpful to know this if you want to visualize the path of the robot. Assume the following physical characteristics:
  • the base frequency is 5kHz (5000 times per second)
  • one stepper motor step moves 1mm linearly for the attached wheel
  • each wheel is 20mm from the center of the robot
• For example,

  14334 L
  

  means that the left motor performs a step in time slice 14334.

The following describes the input of your program:

• Each line of input is one setting, there can be multiple settings per time slice.
• Everything after the pound symbol (#) on a line should be ignored.
• Fields are separated by spaces.
• The following names are used for specifying parameters:
  • lin is a prefix for linear parameters
  • ang is a prefix for angular parameters
  • vel sets the desired top velocity (in number of steps per second), this is a magnitude, so it should be an unsigned integer.
  • acc sets the maximum acceleration (in number os steps per second squared), this is a magnitude, so it should be an unsigned integer.
  • D sets the remaining number of steps. This can be positive or negative.
• A parameter is set by the parameter name, followed immediately by a possibly signed decimal integer for the value
• For example,

  5621 lin.D 234
  

  means that at time slice 5621, reset linear displacement to 234.