Kỹ thuật lập trình hệ cơ điện tử = Programming Engineering in Mechatronics. Chapter V: Hardware Interface Programming79

Visual Studio Serial Port control▪ Visual Studio has a control that performs serial input and output.. SerialPortString^, Int32 Initializes a new instance of the SerialPort class using t

KỸ THUẬT LẬP TRÌNH HỆ CƠ ĐIỆN TỬ Programming Engineering in Mechatronic

Hà Nội, 2018

1 Introduction

signals that pass through each line between the CPU and a peripheral device or communications network

➢ The CPU socket on the motherboard determines which CPU chips can be used in the computer

➢ Peripheral cards, such as a high-end graphics cards, plug into the bus on the motherboard The most common buses are PCI and PCI Express.

https://www.pcmag.com/encyclopedia/term/51988/standards-hardware-interfaces

computers is USB It connects printers, cameras, music players, flash drives and auxiliary hard and optical drives

❖ FireWire is also used for camcorders and hard disks

❖ In addition, SATA is a common hard drive and optical drive interface

❖ The GPIB IEEE 488 standard is used for process control instruments.

❖ The de facto standard for connecting devices to local networks (LANs) is Ethernet, which is also used to hook up a cable or DSL modem.

https://www.pcmag.com/encyclopedia/term/51988/standards-hardware-interfaces

of hardware and your computer

❖ They are relatively simple to use and are very common among

peripherals and especially DIY projects

❖ Many platforms such as Arduino have built in serial communication so they are really easy to set up and use

❖ Many times you may want your project to communicate with your computer in order to have a cool interactive output, a neat sensor that passes data to your computer, or anything else you could possibly

dream up.

Visual Studio Serial Port control

▪ Visual Studio has a control that performs serial input and output It is the SerialPort control and found in the Components toolbox tab.

▪ It is a non visual control Its main properties are set to a common communications rate and are: BaudRate: 9600, DataBits: 8, Parity: None, PortName: COM1, StopBits: One.

▪ Its main event is: DataReceived which occurs when data is received from the port.

SerialPort() Initializes a new instance of the SerialPort class.

SerialPort(IContainer^) Initializes a new instance of the SerialPort class using the

specified IContainer object.

SerialPort(String^) Initializes a new instance of the SerialPort class using the

specified port name.

SerialPort(String^, Int32) Initializes a new instance of the SerialPort class using the

specified port name and baud rate.

SerialPort(String^, Int32, Parity) Initializes a new instance of the SerialPort class using the

specified port name, baud rate, and parity bit.

SerialPort(String^, Int32, Parity,

Visual Studio Serial Port control: Properties

BaseStream Gets the underlyingStreamobject for aSerialPortobject

BaudRate Gets or sets the serial baud rate

BreakState Gets or sets the break signal state

BytesToRead Gets the number of bytes of data in the receive buffer

BytesToWrite Gets the number of bytes of data in the send buffer

CanRaiseEvents Gets a value indicating whether the component can raise an event (Inherited from Component)

CDHolding Gets the state of the Carrier Detect line for the port

Container Gets the IContainerthat contains theComponent (Inherited fromComponent)

CtsHolding Gets the state of the Clear - -Send line.to

DataBits Gets or sets the standard length of data bits per byte

DesignMode Gets a value that indicates whether the Componentis currently in design mode (Inherited fromComponent)

DiscardNull Gets or sets a value indicating whether null bytes are ignored when transmitted between the port and the receive buffe

DsrHolding Gets the state of the Data Set Ready (DSR) signal

DtrEnable Gets or sets a value that enables the Data Terminal Ready (DTR) signal during serial communication

Encoding Gets or sets the byte encoding for pre - and post-transmission conversion of text

Events Gets the list of event handlers that are attached to this Component (Inherited fromComponent)

Visual Studio Serial Port control: Properties

Handshake Gets or sets the handshaking protocol for serial port transmission of data using a value from Handshake

IsOpen Gets a value indicating the open or closed status of the SerialPortobject

NewLine Gets or sets the value used to interpret the end of a call to the ReadLine()and WriteLine(String)methods

Parity Gets or sets the parity -checking protocol

ParityReplace Gets or sets the byte that replaces invalid bytes in a data stream when a parity error occurs

PortName Gets or sets the port for communications, including but not limited to all available COM ports

ReadBufferSize Gets or sets the size of the SerialPortinput buffer

ReadTimeout Gets or sets the number of milliseconds before a time -out occurs when a read operation does not finish

ReceivedBytesThreshold Gets or sets the number of bytes in the internal input buffer before a DataReceivedevent occurs

RtsEnable Gets or sets a value indicating whether the Request to Send (RTS) signal is enabled during serial

communication

Site Gets or sets the ISiteof theComponent (Inherited fromComponent)

StopBits Gets or sets the standard number of stopbits per byte

WriteBufferSize Gets or sets the size of the serial port output buffer

WriteTimeout Gets or sets the number of milliseconds before a time -out occurs when a write operation does not finish

Visual Studio Serial Port control: Methods

Close() Closes the port connection, sets the IsOpenproperty to false, and disposes of the internalStreamobject

CreateObjRef(Type) Creates an object that contains all the relevant information required to generate a proxy used to communicate

with a remote object (Inherited from MarshalByRefObject)

DiscardInBuffer() Discards data from the serial driver's receive buffer

DiscardOutBuffer() Discards data from the serial driver's transmit buffer

Dispose() Releases all resources used by the Component (Inherited fromComponent)

Dispose(Boolean) Releases the unmanaged resources used by the SerialPortand optionally releases the managed resources

Equals(Object) Determines whether the specified object is equal to the current object (Inherited from Object)

GetHashCode() Serves as the default hash function (Inherited from Object)

GetLifetimeService() Retrieves the current lifetime service object that controls the lifetime policy for this instance (Inherited fromMarshalByRefObject)GetPortNames() Gets an array of serial port names for the current computer

GetService(Type) Returns an object that represents a service provided by the Componentor by itsContainer (Inherited

fromComponent)

GetType() Gets theTypeof the current instance (Inherited fromObject)

InitializeLifetimeService() Obtains a lifetime service object to control the lifetime policy for this instance (Inherited from

MarshalByRefObject)

MemberwiseClone() Creates a shallow copy of the current Object (Inherited fromObject)

Visual Studio Serial Port control: Methods

MemberwiseClone(Boolean) Creates a shallow copy of the current MarshalByRefObjectobject (Inherited fromMarshalByRefObject

Read(Byte[], Int32, Int32) Reads a number of bytes from thespecified offset. SerialPortinput buffer and writes those bytes into a byte array at the Read(Char[], Int32, Int32) Reads a number of characters from thea given offset. SerialPortinput buffer and writes them into an array of characterReadByte() Synchronously reads one byte from the SerialPortinput buffer

ReadChar() Synchronously reads one character from the SerialPortinput buffer

ReadExisting() Reads all immediately available bytes, based on the encoding, in both the stream and the input buffer of

theSerialPortobject

ReadLine() Reads up to the NewLinevalue in the input buffer

ReadTo(String) Reads a string up to the specified value in the input buffer

ToString() Returns a(Inherited fromStringComponentcontaining the name of the) Component, if any This method should not be overridden.Write(Byte[], Int32, Int32) Writes a specified number of bytes to the serial port using data from a buffer

Write(Char[], Int32, Int32) Writes a specified number of characters to the serial port using data from a buffer

Write(String) Writes the specified string to the serial port

WriteLine(String) Writes the specified string and the NewLinevalue to the output buffer

Visual Studio Serial Port control: Events

DataReceived Indicates that data has been received through a port represented by

the SerialPort object.

Disposed Occurs when the component is disposed by a call to

the Dispose() method (Inherited from Component )

ErrorReceived Indicates that an error has occurred with a port represented by

a SerialPort object.

PinChanged Indicates that a non -data signal event has occurred on the port

represented by the SerialPort object.

Visual Studio Serial Port control: Remarks

• Use this class to control a serial port file resource This class provides

synchronous and event-driven I/O, access to pin and break states, and access

to serial driver properties Additionally, the functionality of this class can be wrapped in an internal Stream object, accessible through the BaseStream

property, and passed to classes that wrap or use streams.

• The SerialPort class supports the following encodings: ASCIIEncoding ,

UTF8Encoding UnicodeEncoding UTF32Encoding , , , and any encoding defi

in mscorlib.dll where the code page is less than 50000 or the code page is

54936 You can use alternate encodings, but you must use the ReadByte or

Write method and perform the encoding yourself.

Visual Studio Serial Port control: Remarks

• You use the GetPortNames method to retrieve the valid ports for the current computer.

• If a SerialPort object becomes blocked during a read operation, do not abort the thread Instead, either close the base stream or dispose of the SerialPort object.

Serial Port data over USB

Serial Port data over USB

Visual Studio Serial Port control in C++/CLI

Visual Studio Serial Port control in C++/CLI

▪ Find Ports

Visual Studio Serial Port control in C++/CLI

▪ Initialize Port

Visual Studio Serial Port control in C++/CLI

▪ Close Port

Visual Studio Serial Port control in C++/CLI

Example: Read data from Arduino

• Arduino code

Visual Studio Serial Port control in C++/CLI

Example: Turn led ON/OFF

• C++/CLI code

Example: Turn led ON/OFF

"Port Not Opened";

// grab text and store in send buffer

String ^ message = "OFF" ;

// write to serial

if ( this ->serialPort1->IsOpen) this->serialPort1-

>Write(message);

else this->textBoxSendData->Text =

"Port Not Opened";

Example: Turn led ON/OFF

• Arduino code

Example: Turn led ON/OFF

• Arduino code

Example: Turn led ON/OFF

• Circuit Diagram

Serial Data Received Event Handler

▪ Example: Read and Display Temperature

Serial Data Received Event Handler

▪ Example: Read and Display Temperature

• C++/CLI Code private: System::VoidserialPort1_DataReceived(System::Object^ sender,

System::IO::Ports::SerialDataReceivedEventArgs^ ) {e

// check if port is ready for reading

if(this->serialPort1->IsOpen) {

// Reset the text in the result label

this->labelTemperature->Text = String::Empty;

// this will read manually

// give error warning

this->textBoxReceivedData->Text = "Port Not Opened";

}

Serial Data Received Event Handler

▪ Example: Read and Display Temperature

• Arduino Coding

Serial Data Received Event Handler

▪ Example: Read and Display Temperature

• Circuit Diagram

▪ Example: Read and Display Temperature

• C++/CLI Code

▪ Example: Read and Display Temperature

• C++/CLI Code

▪ Example: Read and Display Temperature

• C++/CLI Code

▪ Example: Read and Display Temperature

• C++/CLI Code

▪ Example: Read and Display Temperature

• C++/CLI Code

▪ Example: Read and Display Temperature

• C++/CLI Code