Week 12

On week 12, I continued my research about details of components.

Microcontroller

PIC 16F877A

The microcontroller forms the heart of the system. Its responsibilities include reading the message from the GSM modem and displaying it on LCD. Reading of message from the SIM card inserted into the modem is done by sending the appropriate AT command to the modem. Here we use MICROCONTROLLER 16F877A.

A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable I/O peripherals. Due to simplicity in design and pocket friendly prices, microcontroller is widely adopted for various fields including automobiles, medical science, defense, domestic applications, industrial use, energy management and lots more domains. Microcontrollers are commonly built using CMOS (Complementary Metal Oxide semiconductor) technology resulting optimum performance with the least consumption of power. As it is designed to perform a specific task, latency of the task is fast and is more reliable.

Pin and Description

  

High-Performance RISC CPU

•  Lead-free; RoHS-compliant
• Operating speed: 20 MHz, 200 ns instruction cycle
• Operating voltage: 4.0-5.5V
• Industrial temperature range (-40° to +85°C)
• 15 Interrupt Sources
• 35 single-word instructions
• All single-cycle instructions except for program branches (two-cycle)

Special Microcontroller Features

• Flash Memory: 14.3 Kbytes (8192 words)
• Data SRAM: 368 bytes
• Data EEPROM: 256 bytes
• Self-reprogrammable under software control
• In-Circuit Serial Programming via two pins (5V)
• Watchdog Timer with on-chip RC oscillator
• Programmable code protection
• Power-saving Sleep mode
• Selectable oscillator options
• In-Circuit Debug via two pins