Robotics

Informal definition: a machine that senses its environment and changes its behavior based on program

control of the sensory input.

Major components: • a machine (in our case made of Lego blocks) • sensors (in our case touch/contact and light sensors) • behavior (in our case motion caused by motors and wheels) • program control (in our case the language NQC → RCX for the Hitachi H8 CPU)

Two main types of robots: stationary and mobile

• stationary … welders, painters, • mobile … transport vehicles, submarines, vacuum cleaner, R2D2

Our robots:

• Lego Mindstorms Robot System … originally developed by Fred Martin at the MIT Media Lab … a Lego “brick” with a computer inside … see pictures below

• NQC programming language developed by Dave Baum • Bricx IDE … developed by John Hansen

Process: • design a robotic solution for the problem at hand • construct the robot hardware with appropriate sensors (demo) • write a robot program in Bricx (demo) • compile the program from NQC → RCX • download the program from the PC to the RAM of the robot • execute the program on the robot

Firmware: • operating system • interpreter of RCX code • NQC compiles to RCX which is interpreted to H8 machine language

The RCX Computer • H8/3292 microcontroller

o 8 16-bit registers, 57 instructions, 8 addressing modes o 16 MHz clock o 16 KB on-chip ROM and 512 B on-chip RAM o 4 Timers, 8 A/D converters (10 bits) o Serial Communication Interface (SCI) to communicate with IR input

• 32KB external RAM • IR Transmitter/Receiver (Tx)