Instructions Circuit Diagram

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Servo-motors
We provide the YETI with two special motors, housed in small
compartments and containing a few cog wheels and some control
electronics. The output axle is provided with a single cog wheel.
Electronic engineers call these devices servos. The internal cog wheels
make up a gear-system. In fact the gear slows down the number of
revolutions and compared to the motor axle the output cog wheel will
be turning rather slowly. In fact the output axle will not complete a full
rotation, but instead will cover an angle range up to around 220
degrees. The slow speed however implies a considerable torque or
force to the output axle.
Microcontrollers and programming
A microcontroller accepts a set of 120 basic instructions and a great
amount of combinations of these instructions. A series of instructions
is named a program. In order to process a program, the computer will
have to load the program into its internal memory. The microcontroller
fetches the instruction from the memory and processes the operation.
Having completed the instruction the processor will fetch the next
instruction and processes this one equally, repeating the process in a
continues loop.
Flash-memory
In a standard PC you will have to ‘start’ a program, e.g. a game, before
you are able to play the game. ‘Starting’ a program implies copying the
program from your hard disc into the processor’s memory. Switching
off your PC will remove the program from the processor’s memory and
restarting the PC requires a ‘restart’ for the game-program to play the
game.
A microcontroller however is provided with a special memory device,
called ‘Flash’-memory, in which the program is stored permanently.
Switching off the supply power for the microcontroller will not remove
the program from the ‘Flash’-memory and to remove or modify a
program, you will even have to switch on your microcontroller’s power
supply.
In fact a microcontroller uses ‘Flash’-memory as a permanent proces-
sor memory, storing the program at any time until you decide to delete
the program.