Micro-controllers (PIC) based Application Development

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Team Emertxe
Microcontrollers

Microcontrollers
●
Introduction
●
System Development Concept (Low Level)
●
Understanding Target
● Work Environment and Dev...

Introduction

Introduction
●
What is a Microcontroller
●
General Architectures
●
µP vs µC
● Choosing a Microcontroller

Introduction
What is a Microcontroller?
●
An Integrated Circuit which is capable of being
programmed to preform a specific...

Introduction
General Architectures
●
Shared signals and
memory for code and data
●
Physically separate signals
and storage...

Introduction
µP vs µC - Microprocessors
●
All separate components
●
More flexible
●
More design complexity

Introduction
µP vs µC - Microcontroller
●
All components in single
chip
● Less flexible
●
Less design complexity

Introduction
Choosing a Microcontroller
●
Applications
●
Performance
●
Price
● Availability
●
Availability of Tools
● Spec...

System Development Concepts
(Low Level)

System Development Concept
●
Host and Target
● Host Tools

System Development Concepts
Host and Target
●
Host:
A system which is used to develop the target.
●
Target:
A system which...

System Development Concepts
Host Tools
●
Software
– Cross Compiler : PICC (Lite Version)
– Code Down Loader : usbpicprog
●...

Understanding Target - EmxPICM02

Understanding Target
●
EmxPICM02 Architecture
●
EmxPICM02 Development Board
●
Understanding the Target Controller

Understanding Target
EmxPICM02 Architecture

Understanding Target
EmxPICM02 Development Board
●
PIC16F887
●
GLCD
●
CLCD
●
SSD
●
LEDs
●
Analog Keypad
●
Matrix Keypad
●
...

Understanding Target Controller
PIC16F887

Understanding Target Controller
PIC16F887
●
Architecture
●
Program Memory
●
Data Memory
● Pin Diagram
●
Clocking
● I/O Con...

Understanding Target Controller
PIC16F887 Architecture

Understanding Target Controller
PIC16F887 Program Memory

Understanding Target Controller
PIC16F887 Data Memory

Understanding Target Controller
PIC16F887 Pin Diagram

Understanding Target Controller
PIC16F887 Clocking

Understanding Target Controller
PIC16F887 I/O Config

Work Environment and Development
Guidelines

Work Environment and
Development Guidelines
●
Workspace Creation
●
Code Structure
●
Code Template
● Code Dump Creation

Workspace Creation

Code Structure

$Code Template #ifndef MAIN_H #define MAIN_H #include <htc.h> #endif #include “main.h” void init_config(void) { /* Initiliz...$

Code Dump Creation
●
Compilation using picc would be
$ <path>/picc --chip=16f887 main.c
● Hex code dumping
$ <path>/usbpic...

Lets Roll Out on Interfaces

Lets Roll Out on Interfaces
●
LEDs
●
Digital Keypad
●
Interrupts
●
Timers
●
Clock I/O
●
Analog Inputs
●
SSDs
●
CLCD
●
Matr...

Light Emitting Diodes

LEDs
Introduction
●
Simplest device used in most on the embedded
applications as feedback
●
Works just like diodes
●
Low e...

LEDs
Example
● Which side will
work?

LEDs
Example
ON
● Oops :( wrong
choice. Can you
explain why?

LEDs
Example – Correct Choice :)
● Ooh :) looks like
you know the
funda.

LEDs
Circuit on Board

Digital Keypad

Digital Keypad
●
Introduction
●
Interfacing
●
Input Detection
● Bouncing Effect
●
Circuit on Board

Digital Keypad
Introduction
●
Provides simple and cheap interface
●
Comes in different shapes and sizes
●
Preferable if th...

Digital Keypad
Tactile Switches Interfacing
●
Considering the below design what will be input to the
controller if the swi...

Digital Keypad
Tactile Switches Interfacing
●
Will this solve
the problem
which may arise
in the design
mentioned in
previ...

Digital Keypad
Tactile Switches Interfacing
●
Now will this
solve the
problem which
may arise in the
design
mentioned in
p...

Digital Keypad
Tactile Switches Interfacing
●
What would you call
the this design. Is
there any potential
problem?

Digital Keypad
Tactile Switches Interfacing

Digital Keypad
Triggering Methods

Digital Keypad
Bouncing Effects

Digital Keypad
Circuit on Board

Interrupts

Interrupts
●
Basic Concepts
● Interrupt Source
●
Interrupt Classification
● Interrupt Handling

●
An interrupt is a communication process set up in a
microprocessor or microcontroller in which:
– An internal or externa...

●
Loss of Events
●
Response
● Power Management
Interrupts
Interrupt vs Polling

●
External
●
Timers
● Peripherals
Interrupt
Sources

Interrupt
Classification

Interrupt
Handling

Interrupt
Service Routine (ISR)
●
Similar to a subroutine
●
Attends to the request of an interrupting source
– Clears the ...

Interrupt
Service Routine (ISR)
● What / What Not

Interrupt
Latency
●
Latency is determined by:
– Instruction time (how long is the longest)
– How much of the context must ...

$bit glow_led; void interrupt external_pin(void) { if (INTFLAG) { glow_led = 1; INTFLAG = 0; } } static void init_config(vo...$

Timers

Timers
Introduction
● Resolution  Register Width
● Tick  Up Count or Down Count
● Quantum  System Clock settings
● Scal...

Timers
Example
● Requirement – 5 pulses of 8 µsecs
● Resolution – 8 Bit
● Quantum – 1 µsecs
● General

Timers
Example

Clock I/O
Introduction
● Most peripheral devices depends on Clocking
● Controllers have to generate clock to communicate w...

Clock I/O
Introduction
● The activity on the devices could be on
– Edges
– Levels

Clock I/O
PWM
● Sometimes called as PDM (Pulse Duration Modulation)
● A technique used to vary the active time vs inactive...

Analog Inputs

Analog Inputs
Introduction
●
Very important peripheral in embedded systems for real
time activities
● Multiplexed with nor...

Analog Inputs
SAR

Seven Segment Displays

SSD
Introduction
●
Array of LEDs connected internally
●
Possible configurations are common cathode and common
anode
●
Very...

SSD
Introduction
Segment Data – 10100100 & Control Line - C2
Segment Data – 10010010 & Control Line - C3
Let's assume that...

SSD
Example
Segment Data – 10100100 & Control Line -
C2

SSD
Example
Segment Data – 10010010 & Control Line -
C3

SSD
Example

SSD
Example

SSD
Example

SSD
Example

SSD
Circuit on Board

Character Liquid Crystal Display

CLCD
Introduction
●
Most commonly
used display ASCII
characters
●
Some
customization in
symbols possible
●
Communication
M...

CLCD
Circuit on Board

Matrix Keypad

Matrix Keypad
Introduction
● Used when the more number of user inputs is required and
still want to save the some controll...

Matrix Keypad
Example

Analog Keypad

● Used when the more number of user inputs is required
and still want to save the some controller I/O lines
● Uses a singl...

Analog Inputs
Example

Data Storage

● Mostly used in every Embedded System
● The size and component (memory) of storage depends
upon the requirements
● Modern...

Thank You