lego mindstorms hitachi h8-based rcx brick b.a. juliano, r.s. renner, f. jauregui january 2004...
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LEGO MindstormsHitachi H8-based RCX
brickB.A. Juliano, R.S. Renner, F. Jauregui
January 2004
California State University, ChicoIntelligent Systems Laboratory
Chico, CA 95929-0410http://isl.ecst.csuchico.edu
LEGO Mindstorms
• http://mindstorms.lego.com
Robotics Invention System 2.0
• RIS Kit
Contents of Kit
• RCX™ Microcomputer• CD-ROM Software• Contructopedia™• 3 Guided Challenges• 6 Pro Challenges• USB Infrared Transmitter• 718 pieces, including:• 2 Motors• 2 Touch Sensors• 1 Light Sensor
CompatibilityMinimum Requirements for your PC:
Operating System Windows® 98*
CPU Pentium II 233 MHz
RAM 32 MB
Available Hard Disk Space
115 MB
Mouse Windows® Compatible
SoundSound Blaster 16™ Windows® Compatible Sound
Device
CD-ROM Speed CD 8X
Video Display 800 X 600 SVGA with 4 MB RAM
Colors Colors 16 bit
Modem (optional) 28.8 KBPS
Internet Browser (optional)
Netscape® Navigator or Microsoft™ Internet Explorer
•Not compatible with Windows NT or Windows 2000 operating systems.
RIS 2.0 RCX BrickAn autonomous LEGO microcomputer that can be programmed using a PC. The RCX serves as the brain of LEGO MINDSTORMS inventions.
About the Brick
• LCD (Liquid Crystal Display)• Four buttons• One internal speaker• Three sensor inputs• Three actuator outputs• IR (Infrared) interface
About the Brick
• Hitachi H8 series microcontroller• 8 bit CPU at 16 MHz• 32 KByte RAM• 16 KByte ROM for the BIOS• serial I/O (input/output)• ADC (analog digital converter)• built-in timers
Features
• Instruction set with 57 basic instructions, including:– Multiply and divide instructions– Powerful bit-manipulation
instructions
• High-speed operation– All frequently-used instructions
are executed in two to four states
Software Architecture
• System ROM Layer• Low level control software • Interface to hardware• Second piece of software
– Firmware– Located in RCX ROM
Firmware
• Can bypass system ROM software– Allows complete control of RCX
• Erased when power removed• In RCX RAM• Can use standard Firmware OR
– Can be replaced with others– birickOS
Caution
• When changing batteries you may loose Firmware and all programs– Replace one at a time– Do within one minute
Multi-Tasking
• Threading– Multiple things at one time
• Can create new threads to accomplish Multi-Tasking
Put it All Together
Hitachi H8/3292Microcontroller
Hitachi H8/3292 diagram
Hitachi H8/3292 package
H8/300 CPU• 8-bit data
• 16-bit address space
• 8 X 16 bit registers (r0-r7)– R0 – function return– R7 – stack pointer
• 16 MHz clock
H8/3292 Block Diagram
RCX Memory Layout
Input Devices
• 3 Sensors• 4 Buttons• Battery level monitor• Timers
Light Sensor
•Two components•Light detector•Small light source
•Light turned on to find something close. Amplifies difference between light and dark.
•Great for line following
Light Sensor cont.
• Highly sensitive to ambient light– Sunlight is the worst
• How to solve problem– Take two light sensor readings and
subtract the background light• Sensitive to objects reflective
surface.– Thus, difficult to measure distance.
Light Sensor cont.
• Light measured as– 0% (total darkness) to– 100% (very bright).
Light Sensor cont.
voltagemeasurement
light energy
electrical flow
voltagemeasurement
light energy
photo-transistor
Uses for Light Sensor
• Navigation • Black on white• White on black
• Find light• Avoid light• Sort colors
• black Lego bricks• yellow Lego bricks.
• Input Device • colors or gray levels on paper.
Touch Sensor
force voltagemeasurement
electrical flow
Uses for Touch Sensor
• Detect contact • Wall detection• Internal contact
• Arm contact with internal parts
• Constant contact• Make sure bot does not fall off of a
table
• Input Device• Use as a push button
Others
• You can buy or make you own sensors– Example: Temperature sensor– Search online– Lots of resources
http://www.plazaearth.com/usr/gasperi/lego.htm
Temperature Sensor
Temperature Sensor cont.
Temperature Sensor cont.
Temperature Sensor cont.
Output Devices
• 3 Actuator Ports• 5-segment LCD• Speaker
Bidirectional Device
• Infrared port
LegoOS Network Protocol (LNP)
• Communication between brickOS and host computers
• If packets arrive– Free of corruption
• Collision problems