CS 102B Robot Design Thursday, 92804

1
CS 102B Robot DesignThursday, 9/28/04

• Todays Class
• Introduction to NQC
• NQC Lab
• Reading
• Ferrari, Chap. 6
• Assignments
• Work on Sumobot project
• Complete lab work assigned today.
• NO CLASS ON THURSDAY
• NO OFFICE HOURS UNTIL MONDAY 10/4/04

2
Limits of RCX Code

• Example 1 Program robot to distinguish dark from
  light that works in a variety of room conditions.
• Example 2 Program robot to wander randomly,
  recording 50 light readings for later analysis
• These tasks cannot be done with RCX Code.

3
Alternative Languages

• ROBOLAB (see Chap. 16 in Erwin text)
• A graphical programming language (like RCX code)
  commercial product
• Extensions of general (text-based) prgoramming
  languages
• Visual BASIC (Erwin Chap. 15)
• leJOS extension of Java
• NQC extension of C
• leJOS and NQC are open-source, freely available
  on intrnet.

4
NQC

• NQC is short for Not Quite C
• Written by Dave Baum
• Text-based language
• Based on C programming language, but specialized
  for robots, and simpler than full C
• Syntax is similar to C and Java
• Helpful for transition into CS 106 and other
  programming courses

5
GUIs for NQC

• GUI means graphic user interface
• An environment providing windows, menus, button,
  etc. to make writing and using programs easier
• RcxCC RCX Command Center and
• Bricx CC (updated version)
• A GUI for using NQC in Windows environment
• Written by Mark Overmars (Netherlands)
• Up-to-date version available on our course web
  site (dont use older version from disk with
  Erwin text)
• MacNQC
• A GUI for using NQC in Mac environment
• Available on disk with Erwin Text

6
RcxCC/BricxCC

• Our next project will use RcxCC, which is
  installed on lab machines
• You can install it on your own machine from the
  text disk.
• Once installed, a folder is created containing
• An executable file to run RcxCC
• A folder with three Word documents with
  information on how to use NQC and RxcCC

7
A Simple example of NQC code
task main() SetSensor(SENSOR_1,
SENSOR_LIGHT) On(OUT_A OUT_C) while(true)
if (SENSOR_1 lt 43) SetDirection(OUT_A
OUT_C, OUT_FWD) else
SetDirection(OUT_A OUT_C, OUT_REV)

8
Comparing NQC with RCX Code

• Every NQC program contains a block task main()
• Output ports are called OUT_A, OUT_B, OUT_C
• Control output with statements OnFwd(), OnRev(),
  Off(), etc.
• Input ports are called SENSOR_1 (or 2 or 3)

• Every RCX program starts with a program block
• On/Off blocks refer to output ports A, B, C
• Sensor blocks assign input ports to sensors, and
  associate actions with sensor readings

9
Yellow Book Documentation

• Contains 3 documents
• Part 1 is a short text on how to write robot
  control programs using NQC
• Part 2 is a reference guide on how to use the
  RcxCC GUI interface
• Part 3 is a reference guide for NQC
• Inside and back covers contain a brief,
  alphabetized NQC reference