California State University, Chico Intelligent Systems Laboratory Chico, CA 95929-0410 http://isl.ecst.csuchico.edu LEGO Mindstorms Hitachi H8-based RCX brick B.A. Juliano, R.S. Renner, F. Jauregui
January 2004 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
Compatibility Minimum 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
Sound Sound 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 Brick An 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 H8/3292 Microcontroller 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. light energy voltage
measurement photo-transistor light energy voltage measurement
electrical flow 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 electrical flow force voltage measurement 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
