Enclosed is the Team 254 2011 FRC Codebase. This code is released
under the BSD 2-Clause License. A copy of this license is included
in the COPYING file.

The relevant Chief Delphi thread is located at http://www.chiefdelphi.com/forums/showthread.php?p=1085065
Please post a comment there if you have any questions or find this code helpful.

Most of the functions and classes are documented or otherwise
simple and self-explanatory. The logic inside, however, has often
become quite convoluted (especially as the season progressed and
new features were incorporated). This is our major concern with
the system but we will be working on better documentation in the
future.

CONTENTS:
AUTHORS lists the main contributors to this codebase

COPYING contains a copy of the BSD License

main.cpp includes our SimpleRobot-derived class, including logic for
autonomous mode and interfacing with the control board in disbaled
and teleoperated modes

matlab/ contains the code for our full state feedback control system.
matrix.c and matrix.h are a C matrix library developed by Parker Schuh;
it was chosen because we needed a library quickly and it was on hand.
In a future version we would write our own C++-style library (with
nice objects and methods and operators) for better code readability.

scripts/ contains a short script to automate the uploading of our
constants CSV to the robot. The copying script was written by Eric
Bakan, the Ruby watcher was developed by Parker Schuh.

RobotConfig.csv contains all the constants used by the system - PID
values, preset heights, autonomous mode distances and angles, etc.

Source/ contains the core source code used on the robot. Functionality
is described below

FUNCTIONALITY:
main.cpp creates a SimpleRobot
The robot then creates a CSVReader for reading the CSV file,
a RobotState for storing what the robot is supposed to be doing,
for getting the sensor values, setting the outputs, and helper
functions for writing auto modes quickly without knowing the details,
a ControlBoard for reading the joysticks and talking to the
control loops, and a ControlLoops which forks a notifier and
runs all the control loops at m_robot->dt.  Anything which modifies
the RobotState must have the robot state lock, or corruption might occur.

The Reset functions are called on the robot state and control loops
when the bot is initialized, and goes from disabled to enabled.
The CSV file is re-read then as well.

CommonIncludes.hpp includes many utility functions (converting units,
etc.)

AccelFilterBase, ContinuousAccelFilter, and
DiscreteAccelFilter are all acceleration profile generators used
in autonomous drive control. The discrete profiler was generated
first because it was simpler but the continuous profile is far
superior.

The CSVReader is used to read constants from a file for use in the
program. This enables a team to not have to redeploy code to change
constants when tuning - simply modify a file on the robot and reset
the CSVReader (often when enabling/disabling the robot)

ControlBoard reads values from the control board, handles much of
its logic (semi-autonomous actions, running filters on joystick inputs,
etc. In its update loop ControlBoard updates RobotState with all its
values - control loop targets, statuses of toggle switches, etc.

ControlLoops/ contains control loops for each of the major robot systems.
The arm and elevator run on PID loops with target positions/angles,
minibot and rollers are quasi-FSMs and merely control logic, and
the drive control is the most complex, handling both teleoperated
driver control and autonomous full state feedback control.

ControlLoops creates a new thread to update each of the control loops
every 10ms.

RobotState is the core of the system - it is the data structure that
is passed around between the main robot, the control board, and the
control loops. Since the system is multithreaded, it is of utmost
importance to make sure each system acquires the robot's mutex before
it performs operations. In addition to holding data, RobotState also
provides some useful threadsafe and non-threadsafe functions to
interface with its data members. There is limited distinction between
threadsafe and non-threadsafe functions at the moment, but this is
a point of improvement for us next year.

Together this forms a system where main.cpp controls whether the program
will run autonomously or accept user input. If it needs to run autonomously,
a new autonomous thread is spawned. Otherwise if there is user input,
the system tells ControlBoard to update the RobotState based on the current
inputs. At the same time, ControlLoops is in its independent thread updating
the robot's outputs, whether in autonomous or teleop mode.

If you have any questions, contact Eric Bakan at [email protected]