THE RCX PROCESSOR STARTING POINT
TODAY'S FEATURES
All of the RCX activities and computer code written for the
Cyber Laboratory will be in Not Quite C (NQC). For Software installation
procedures visit: http://www.kipr.org/botball/tournament/bb2000/install_instruc.html
LOADING A PROGRAM
The RCX processor communicates with your desktop computer
via infrared transmission. A gray serial port cable connects to
comm port 1 on the back side of your computer. The port cable
attaches to the LEGO infrared transmission tower (Figure 1). Once
this equipment is attached, turn on your RCX processor. Your RCX
must be on at all times when downloading a program. Arrange the
RCX and IR tower so that they are facing one another. To download
and run NQC, your RCX must have an operating system known as Firmware.
Firmware is similar to Windows 95 in that it supports software.
The Firmware for the RCX brick is the operating system for the
RCX and Firmware is needed to to allow any higher level programming
to be done. The firmware we use is LEGO's and is used both for
NQC and for the LEGO software. Some people have written their
own Firmware and use it to support other programming environments
(Like RCX FORTH). NOTE: If you are having trouble loading or running
an NQC program, the first thing you should do is check your FIRMWARE.
Figure 1. Infrared
tower communicating with the RCX processor
If your RCX display screen resembles Figure 2 with 00.00 to
the left of the human icon, your Firmware is loaded and your can
open up NQC and download a program. If your RCX screen looks like
Figure 3, you need to download the Firmware file. Here's how it's
done:
DOWN LOAD FIRMWARE, DOWNLOAD FIRMWARE,
DOWNLOAD FIRMWARE
1. Turn on your RCX. Open NQC and under Tools (PC) or Program
(Mac) select Download Firmware. If you have to locate the file,
it is called: FIRM0309.LGO
2. Download the Firmware. This process will take approximately
2 or 3 minutes. Do not disturb the processor while loading.
3. After the Firmware has been loaded, wait a couple seconds
after you hear the beeps before you pick it up.
4. Turn the processor off and on again. Your screen should
look like Figure 2.
Figure 2. An RCX
processor with Firmware loaded (notice the 00.00 on the screen)
Now you are ready to download your NQC computer programs.
If this is your first experience with NQC, go to the Cyber
Lab computer programming page, kick around some of the programs,
load and run. Below are directions on how to connect the motors
and sensors.
Figure 3. An RCX
processor without Firmware (notice no 00.00 on the screen)
Motors and motor connectors attach
to RCX ports A, B, and C (Figure 4). Notice that the motor connectors
contain metal within and on the outside knobs of a 2x2 brick.
You can change the polarity of the wires by rearranging the connections
on the RCX ports. For example, if your computer program directs
the RCX to spin your robot's motors forward but, they actually
spin in reverse or in opposite directions, you simply need to
adjust the wire orientation.
Figure
4. RCX ports A, B, and C are for motors only
Sensors attach to RCX ports 1,
2, or 3 (Figure 5). Your computer program will determine where
you place your sensors. The LEGO light sensor has its own connector
wire. Touch sensors require a motor connection wire.
Figure
5. RCX ports 1, 2, and 3 are for sensors only
The RCX and NQC combination is probably the easiest way to learn about programming
an autonomous robot. Once you feel familiar with the RCX processor and NQC language,
you'll be ready to attack Interactive C (IC) and the Handy Board. Here is a
4 hour design and test activity (Test and Design Autonomous
Robots) that will help you learn the basics of NQC and provide you with
a few fun applications designed to familiarize you with this fascinating technology.
Good luck!
Please send any questions or comments to curriculum@kipr.org
Downloading
Firmware