Instructor:Mohsen Sarakbi

PIC Microcontroller Review

Communication PIC-Microcontroller LabCourse by JAOM Center, Feb. 2013

Definitions of Control Systems

A control system is a collection of components workingtogether under the direction of some machine intelligence.

In most cases, electronic circuits provide the intelligence, andelectromechanical components such as sensors and motorsprovide the interface to the physical world.

Parts of Control System

Parts of Control System

Every control system has (at least) a controller and an actuator (alsocalled a final control element).

The Controller is the intelligence of the system and is usuallyelectronic.

The input to the controller is called the Set point, which is a signalrepresenting the desired system output.

The Actuator is an electromechanical device that takes the signal fromthe controller and converts it into some kind of physical action.Examples of typical actuators would be an electric motor, an electricallycontrolled valve, or a heating element.

The last block is labeled Process and has an output labeled Controlledvariable. The process block represents the physical process beingaffected by the actuator, and the controlled variable is the measurableresult of that process.

Control System Classifications Open-Loop Control Systems:The controller never actually

knows if the actuator did what it was supposed to.

Closed-Loop Control Systems: The output of the process(controlled variable) is constantly monitored by a sensor.

Microcontrollers

The microcontroller is simply a computer on a chip.

A microcontroller differs from microprocessor; it usuallyincludes a central processor (CPU), input and output ports,memory for program and data storage, an internal clock, andone or more peripheral devices such as timers, counters,analog-to-digital converters (ADC) and serialcommunication facilities.

Microcontrollers

PIC Microcontrollers

PIC is the name for the Microchip microcontroller (MCU)family, consisting of a microprocessor, I/O ports, timers andother internal, integrated hardware. The main advantages arelow external part count, a wide range of chip sizes greatavailability of compilers and source code and easyprogramming.

In our course we’ll use the Microchip products (PIC16F877A)microcontroller.

PIC16F877A Features

o High-performance RISC CPUo 8 Kbytes of FLASH Program Memoryo 368 bytes of Data Memory (RAM)o 256 bytes of EEPROM Data Memoryo 33 I/O pins: (5 ports: A(6), B(8), C(8), D(8) and E(3))o 4-20 MHz operating speedo Wide operating voltage range: 2.0V to 5.5V.o Max. 25 mA current from an output pin.

PIC16F877A Features

MikroBasic

Create a Project

Programming …

PIC Lab

ON/OFF LED IF Statements & Loops (WHILE & FOR) Procedures LCD USART TX/RX Analog input (Temp on LCD)

Combined Scenario ..