Instrukcja obsługi Microchip PIC24FJ128GL408

Microchip Niesklasyfikowane PIC24FJ128GL408

Przeczytaj poniżej 📖 instrukcję obsługi w języku polskim dla Microchip PIC24FJ128GL408 (42 stron) w kategorii Niesklasyfikowane. Ta instrukcja była pomocna dla 5 osób i została oceniona przez 2 użytkowników na średnio 4.5 gwiazdek

Pobierz PDF

Strona 1/42

AN1071

INTRODUCTION

Infrared communication is a low-cost method of

providing wireless, point-to-point communication

between two devices. The Infrared Data Association,

often referred to as IrDA, was formed in 1994 to

develop standard methods for communicating over

short-range infrared transmissions. These standards

have continued to evolve and gain in popularity. Now, a

wide variety of devices implement the IrDA standard

specification, including computers, printers, PDAs, cell

phones, watches and other instruments.

Microchip’s 16-bit and 32-bit microcontrollers are a

perfect fit for applications wanting to support IrDA

standard communication. These low-cost

microcontrollers, with their built-in IrDA standard

support, provide an inexpensive solution with plenty of

computing power.

IrDA® STANDARD

Overview

The IrDA standard specification is a half-duplex

communication protocol with Serial Infrared (SIR)

transmission speeds similar to those supported by an

RS-232 port (9600 bps, 19.2 kbps, 38.4 kbps,

57.6 kbps and 115.2 kbps). Microchip currently

supports only the SIR transmission speeds.

The half-duplex nature of the communications is due to

the fact that the receiver is blinded by the light of its own

transmitter. The infrared transceiver transmits pulses in

a cone with a half-angle between 15 and 30 degrees

(Figure 1). The pulses must be visible from a distance

of one meter, but must not be so bright that the receiver

is overwhelmed at close distances. In practice, optimal

positioning for a receiver is usually a distance of 5 cm

to 60 cm from the transmitter, in the center of the

transmission cone.

Protocols

The initial specifications developed by the Infrared

Data Association provided a mechanism for converting

existing serial interfaces to infrared interfaces. These

protocols closely mimic standard serial interfaces. As

the infrared communication mechanism gained

popularity, more protocols were created to tailor the

communication format for different types of end

applications.

The infrared communication support is designed as a

Stack. Figure 2 shows the basic structure of the Stack.

FIGURE 1: OPTICAL PORT ANGLES

Author: Kim Otten

Microchip Technology Inc.

15-30 Degrees Half-Angle ≥ 15 Degrees Half-Angle

ReceiverTransmitter

IrDA® Standard Stack for Microchip 16-bit and

32-bit Microcontrollers

AN1071

FIGURE 2: IrDA® STANDARD

PROTOCOL STACK LAYERS

The Stack layers perform the following functions:

• Driver – Provides an interface between the Stack

and the microcontroller.

• Framer – Prepares the IrLAP frame for transmis-

sion over the physical serial medium by wrapping

it within a frame wrapper and encoding control

characters in the data payload (with byte and bit

stuffing) to make them transparent to the frame

receiver. The framer receiver converts the

encoded, transparent bytes back to their original

values before validating and storing the frame in

the receive queue.

• IrLAP (Infrared Link Access Protocol) – Provides

a device-to-device connection for the reliable,

ordered transfer of data. Also provides device

discovery procedures.

• IrLMP (Link Management Protocol) – Provides

fundamental discovery, multiplexing and link

control operations between stations. It supports

multiplexing of multiple applications over a single

IrLAP link along with protocol and service

discovery through the IAS.

• IAS (Information Access Service) – A mini

database of the services provided by the device.

• TinyTP (Tiny Transport Protocol) – Provides flow

control on IrLMP connections with an optional

segmentation and reassembly service.

The current implementation of the Microchip IrDA

Standard Stack allows access to the Stack through one

of three different protocols:

• IrCOMM 3-Wire Raw

This protocol is designed to emulate a simple

serial interface consisting of two wires: a receive

and a transmit line. (The third wire, ground, is not

emulated). This protocol is also known as IrLPT,

designed to emulate a PC parallel port interface.

• IrCOMM 9-Wire Cooked

This protocol is designed to emulate a serial

interface with either hardware or software

handshaking.

• OBEX

A higher level protocol, designed to simplify

sending and receiving data objects.

These protocols and the application interfaces to them

are described below.

Device Types

There are two basic types of devices:

•Client (or Primary)

This device initiates the connection.

•Server (or Secondary)

This device responds only when connected to.

A third type of device, called a Peer device, can act as

a Client or a Server. An example of a Peer device is a

PDA, which can either beam information to another

PDA or receive information from another PDA.

Typically, IrCOMM applications are Clients or Servers.

User Application

Protocol

TinyTP

IrLMP

IrLAP

Framer

Driver

IAS

AN1071

HARDWARE DESIGN

Many members of Microchip’s families of 16-bit and 32-

bit microcontrollers provide native IrDA standard

support through their UART modules. This greatly

simplifies the hardware design (Figure 3).

For demonstration and prototyping purposes,

Microchip has created the IrDA® PICtail™ Plus card

(AC164124) for use with the Explorer 16 Development

Board (DM240001).

FIGURE 3: BLOCK DIAGRAM

SOFTWARE DESIGN

Overview

The Microchip IrDA Standard Stack is distributed as a

set of libraries, with source code provided for the lowest

level drivers (see Appendix A: “Source Code”). This

allows the Stack to be tailored to account for:

• Device family

• Device clock speed

• Protocol

• Device type

Due to the nature of the libraries, some operational

parameters are fixed. These include the following

parameters shown in Table 1.

TABLE 1: FIXED OPERATIONAL PARAMETERS

16/32-bit PIC®

U1TX

U1RX

Infrared

Transmitter/

Receiver

Microcontroller

Item Value Effect

Internal Timer Timer 2 Timer2 is unavailable to the application and Timer3 may be used only

as a 16-bit timer.

Interrupts vs. Polling Interrupts The UART receive and transmit interrupts are used. Since these

interrupts are vectored, this method provides the quickest, most

reliable method of interfacing with the peripheral.

Window Size 1Maximum number of information frames that can be transmitted before

an Acknowledge is received. This parameter is set for minimum RAM

usage.

Data Frame Size 64 Maximum LAP frame size. This parameter is set for minimum RAM

usage.

Specyfikacje produktu

Marka:	Microchip
Kategoria:	Niesklasyfikowane
Model:	PIC24FJ128GL408

Potrzebujesz pomocy?

Jeśli potrzebujesz pomocy z Microchip PIC24FJ128GL408, zadaj pytanie poniżej, a inni użytkownicy Ci odpowiedzą

Twoje imię*

Twój email*

Napisz tutaj swoje pytanie

Instrukcje Niesklasyfikowane Microchip

Microchip ATECC608B Instrukcja

7 Października 2024

Microchip HV860 Instrukcja

7 Października 2024

Microchip EVB-LAN9255 Instrukcja

7 Października 2024

Microchip LX4580 Instrukcja

7 Października 2024

Microchip LX7720 Instrukcja

7 Października 2024

Microchip AT32UC3C0128C Instrukcja

4 Października 2024

Microchip AT32UC3A3256 Instrukcja

4 Października 2024

Microchip AT32UC3A364 Instrukcja

4 Października 2024

Microchip AT32UC3B0256 Instrukcja

4 Października 2024

Microchip AT32UC3A0512 Instrukcja

4 Października 2024

Instrukcje Niesklasyfikowane

Najnowsze instrukcje dla Niesklasyfikowane

Black Diamond BD1121530000ALL1 Instrukcja

15 Października 2024

Husqvarna K 970 SmartGuard Instrukcja

15 Października 2024

Stihl HT 70 Instrukcja

15 Października 2024

Ernesto H14270 Instrukcja

15 Października 2024

Uniden BT MIC KIT Instrukcja

15 Października 2024

Vaude Omnis Bike 26 Instrukcja

15 Października 2024

ART ProChannel II Instrukcja

15 Października 2024

Aukey DR02J Instrukcja

15 Października 2024

Master Lock 653EURD Instrukcja

15 Października 2024

Roland FR-18 Diatonic Instrukcja

15 Października 2024