Concept 3 – Micro controller Hardware
Micro controllers range from 8 pin to 80 pin devices.
The pins generally present are:
2 pins for the power supply, generally 5V. Can it work without a power supply?
2 pins for the crystal. It is a clock telling the micro to carry out an instruction or part of an
instruction with every pulse it generates.
1 pin for RESET. Tells the micro to start carrying out the instructions from the start.
A reset always occurs when a micro is switched ON.
2 pins for communication. Generally called Rx and Tx, one for Receiving and another for
transmitting.
1 or more pins for input. Generally switches.
1 or more pins for output. LCD displays, LED etc.
1 or more pins for interrupts or event counters, for immediate action or for counting
number of pulses.
Concept 3