- The software is written using C language and communicates with the Serial Port using Win32 API. In Windows,Serial ports are named as COM1, COM2,COM3. COM1 and COM2 usually refer to the hardware serial ports present in the PC while COM numbers in double digits like COM32, COM54,COM24. Etc are given to USB to Serial Converters or PCI serial port extenders.
- The Serial Programming Guide for POSIX Operating Systems will teach you how to successfully, efficiently, and portably program the serial ports on your UNIX® workstation or PC.
Serial Port Sample. Serial Port Sample This Sample program contains code which opens two UART COM port to send and recieve data via serial UART. I finally got a chance to do a complete vs c tutorial series for serial com port. You can download the example code at source forge http://sourceforge.net/.
Definition
MarshalByRefObjectMarshalByRefObjectMarshalByRefObjectMarshalByRefObject
SerialPort![Programming Programming](/uploads/1/2/6/5/126597983/825616923.jpeg)
Examples
The following code example demonstrates the use of the SerialPort class to allow two users to chat from two separate computers connected by a null modem cable. In this example, the users are prompted for the port settings and a username before chatting. Both computers must be executing the program to achieve full functionality of this example.
Remarks
![Using Using](/uploads/1/2/6/5/126597983/590674493.png)
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 defined 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.
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.
Constructors
SerialPort()SerialPort()SerialPort()SerialPort() | Initializes a new instance of the SerialPort class. |
SerialPort(IContainer)SerialPort(IContainer)SerialPort(IContainer)SerialPort(IContainer) | Initializes a new instance of the SerialPort class using the specified IContainer object. |
SerialPort(String)SerialPort(String)SerialPort(String)SerialPort(String) | Initializes a new instance of the SerialPort class using the specified port name. |
SerialPort(String, Int32)SerialPort(String, Int32)SerialPort(String, Int32)SerialPort(String, Int32) | Initializes a new instance of the SerialPort class using the specified port name and baud rate. Adobe Photoshop CS6 Direct Download Full Software Free For Windows Full Version Adobe Photoshop CS6 Full free. software download 2016 Full Version Adobe Photoshop CS6 For Free. Adobe Photoshop CS6 For Windows: Photoshop Updated CS6 2016 Updated Version now have some incredible abilities to do it perfect work both in visual and graphics. Download full Adobe Photoshop CS6 for Windows PC, Get clean malware free offline installer for Photoshop Creative Suite 6 from direct resume-able high speed download link, This release of Adobe Photoshop CS6 extended portable could be installed on any edition of microsoft windows. Adobe Photoshop CS6, free download. Award-winning image editing suite with professional digital imaging tools, effects, filters and plug-in support powered by the Mercury Graphics Engine. Review of Photoshop CS5. Includes tests and PC download for Windows 32 and 64-bit systems. Photoshop cs6 pc software, free download. Adobe Photoshop CS6 For PC Free Download Latest Version For Windows Os's (XP/7/8/10). Get an offline installer setup file with a single, direct and secure download link. Adobe Photoshop CS6 Free Download is compatible with both Windows 32 and 64 bit. Free download Adobe Photoshop CS6 full latest version for windows and Mac IOS. Download best photoshop software from free providing website “Civil Engineer 9”. This version is so powerful and more workable and the version are most popular to professionally graphics editing. |
SerialPort(String, Int32, Parity)SerialPort(String, Int32, Parity)SerialPort(String, Int32, Parity)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, Int32)SerialPort(String, Int32, Parity, Int32)SerialPort(String, Int32, Parity, Int32)SerialPort(String, Int32, Parity, Int32) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, parity bit, and data bits. |
SerialPort(String, Int32, Parity, Int32, StopBits)SerialPort(String, Int32, Parity, Int32, StopBits)SerialPort(String, Int32, Parity, Int32, StopBits)SerialPort(String, Int32, Parity, Int32, StopBits) | Initializes a new instance of the SerialPort class using the specified port name, baud rate, parity bit, data bits, and stop bit. |
Fields
InfiniteTimeoutInfiniteTimeoutInfiniteTimeoutInfiniteTimeout | Indicates that no time-out should occur. |
Properties
C Serial Port
BaseStreamBaseStreamBaseStreamBaseStream | Gets the underlying Stream object for a SerialPort object. |
BaudRateBaudRateBaudRateBaudRate | Gets or sets the serial baud rate. |
BreakStateBreakStateBreakStateBreakState | Gets or sets the break signal state. |
BytesToReadBytesToReadBytesToReadBytesToRead | Gets the number of bytes of data in the receive buffer. |
BytesToWriteBytesToWriteBytesToWriteBytesToWrite | Gets the number of bytes of data in the send buffer. |
CanRaiseEventsCanRaiseEventsCanRaiseEventsCanRaiseEvents | Gets a value indicating whether the component can raise an event. (Inherited from Component) |
CDHoldingCDHoldingCDHoldingCDHolding | Gets the state of the Carrier Detect line for the port. |
ContainerContainerContainerContainer | Gets the IContainer that contains the Component. (Inherited from Component) |
CtsHoldingCtsHoldingCtsHoldingCtsHolding | Gets the state of the Clear-to-Send line. |
DataBitsDataBitsDataBitsDataBits | Gets or sets the standard length of data bits per byte. |
DesignModeDesignModeDesignModeDesignMode | Gets a value that indicates whether the Component is currently in design mode. (Inherited from Component) |
DiscardNullDiscardNullDiscardNullDiscardNull | Gets or sets a value indicating whether null bytes are ignored when transmitted between the port and the receive buffer. |
DsrHoldingDsrHoldingDsrHoldingDsrHolding | Gets the state of the Data Set Ready (DSR) signal. |
DtrEnableDtrEnableDtrEnableDtrEnable | Gets or sets a value that enables the Data Terminal Ready (DTR) signal during serial communication. |
EncodingEncodingEncodingEncoding | Gets or sets the byte encoding for pre- and post-transmission conversion of text. |
EventsEventsEventsEvents | Gets the list of event handlers that are attached to this Component. (Inherited from Component) |
HandshakeHandshakeHandshakeHandshake | Gets or sets the handshaking protocol for serial port transmission of data using a value from Handshake. |
IsOpenIsOpenIsOpenIsOpen | Gets a value indicating the open or closed status of the SerialPort object. |
NewLineNewLineNewLineNewLine | Gets or sets the value used to interpret the end of a call to the ReadLine() and WriteLine(String) methods. |
ParityParityParityParity | Gets or sets the parity-checking protocol. |
ParityReplaceParityReplaceParityReplaceParityReplace | Gets or sets the byte that replaces invalid bytes in a data stream when a parity error occurs. |
PortNamePortNamePortNamePortName | Gets or sets the port for communications, including but not limited to all available COM ports. |
ReadBufferSizeReadBufferSizeReadBufferSizeReadBufferSize | Gets or sets the size of the SerialPort input buffer. |
ReadTimeoutReadTimeoutReadTimeoutReadTimeout | Gets or sets the number of milliseconds before a time-out occurs when a read operation does not finish. |
ReceivedBytesThresholdReceivedBytesThresholdReceivedBytesThresholdReceivedBytesThreshold | Gets or sets the number of bytes in the internal input buffer before a DataReceived event occurs. |
RtsEnableRtsEnableRtsEnableRtsEnable | Gets or sets a value indicating whether the Request to Send (RTS) signal is enabled during serial communication. |
SiteSiteSiteSite | Gets or sets the ISite of the Component. (Inherited from Component) |
StopBitsStopBitsStopBitsStopBits | Gets or sets the standard number of stopbits per byte. |
WriteBufferSizeWriteBufferSizeWriteBufferSizeWriteBufferSize | Gets or sets the size of the serial port output buffer. |
WriteTimeoutWriteTimeoutWriteTimeoutWriteTimeout | Gets or sets the number of milliseconds before a time-out occurs when a write operation does not finish. |
Methods
Close()Close()Close()Close() | Closes the port connection, sets the IsOpen property to false , and disposes of the internal Stream object. |
CreateObjRef(Type)CreateObjRef(Type)CreateObjRef(Type)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()DiscardInBuffer()DiscardInBuffer()DiscardInBuffer() | Discards data from the serial driver's receive buffer. |
DiscardOutBuffer()DiscardOutBuffer()DiscardOutBuffer()DiscardOutBuffer() | Discards data from the serial driver's transmit buffer. |
Dispose()Dispose()Dispose()Dispose() | Releases all resources used by the Component. (Inherited from Component) |
Dispose(Boolean)Dispose(Boolean)Dispose(Boolean)Dispose(Boolean) | Releases the unmanaged resources used by the SerialPort and optionally releases the managed resources. |
Equals(Object)Equals(Object)Equals(Object)Equals(Object) | Determines whether the specified object is equal to the current object. (Inherited from Object) |
GetHashCode()GetHashCode()GetHashCode()GetHashCode() | Serves as the default hash function. (Inherited from Object) |
GetLifetimeService()GetLifetimeService()GetLifetimeService()GetLifetimeService() | Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject) |
GetPortNames()GetPortNames()GetPortNames()GetPortNames() | Gets an array of serial port names for the current computer. |
GetService(Type)GetService(Type)GetService(Type)GetService(Type) | Returns an object that represents a service provided by the Component or by its Container. (Inherited from Component) |
GetType()GetType()GetType()GetType() | Gets the Type of the current instance. (Inherited from Object) |
InitializeLifetimeService()InitializeLifetimeService()InitializeLifetimeService()InitializeLifetimeService() | Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject) |
MemberwiseClone()MemberwiseClone()MemberwiseClone()MemberwiseClone() | Creates a shallow copy of the current Object. (Inherited from Object) |
MemberwiseClone(Boolean)MemberwiseClone(Boolean)MemberwiseClone(Boolean)MemberwiseClone(Boolean) | Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject) |
Open()Open()Open()Open() | Opens a new serial port connection. |
Read(Byte[], Int32, Int32)Read(Byte[], Int32, Int32)Read(Byte[], Int32, Int32)Read(Byte[], Int32, Int32) | Reads a number of bytes from the SerialPort input buffer and writes those bytes into a byte array at the specified offset. |
Read(Char[], Int32, Int32)Read(Char[], Int32, Int32)Read(Char[], Int32, Int32)Read(Char[], Int32, Int32) | Reads a number of characters from the SerialPort input buffer and writes them into an array of characters at a given offset. |
ReadByte()ReadByte()ReadByte()ReadByte() | Synchronously reads one byte from the SerialPort input buffer. |
ReadChar()ReadChar()ReadChar()ReadChar() | Synchronously reads one character from the SerialPort input buffer. |
ReadExisting()ReadExisting()ReadExisting()ReadExisting() | Reads all immediately available bytes, based on the encoding, in both the stream and the input buffer of the SerialPort object. |
ReadLine()ReadLine()ReadLine()ReadLine() | Reads up to the NewLine value in the input buffer. |
ReadTo(String)ReadTo(String)ReadTo(String)ReadTo(String) | Reads a string up to the specified value in the input buffer. |
ToString()ToString()ToString()ToString() | Returns a String containing the name of the Component, if any. This method should not be overridden. (Inherited from Component) |
Write(Byte[], Int32, Int32)Write(Byte[], Int32, Int32)Write(Byte[], Int32, Int32)Write(Byte[], Int32, Int32) | Writes a specified number of bytes to the serial port using data from a buffer. |
Write(Char[], Int32, Int32)Write(Char[], Int32, Int32)Write(Char[], Int32, Int32)Write(Char[], Int32, Int32) | Writes a specified number of characters to the serial port using data from a buffer. |
Write(String)Write(String)Write(String)Write(String) | Writes the specified string to the serial port. |
WriteLine(String)WriteLine(String)WriteLine(String)WriteLine(String) | Writes the specified string and the NewLine value to the output buffer. |
Events
DataReceivedDataReceivedDataReceivedDataReceived | Indicates that data has been received through a port represented by the SerialPort object. |
DisposedDisposedDisposedDisposed | Occurs when the component is disposed by a call to the Dispose() method. (Inherited from Component) |
ErrorReceivedErrorReceivedErrorReceivedErrorReceived | Indicates that an error has occurred with a port represented by a SerialPort object. |
PinChangedPinChangedPinChangedPinChanged | Indicates that a non-data signal event has occurred on the port represented by the SerialPort object. |
Security
SecurityPermission
for the ability to call unmanaged code. Associated enumeration: UnmanagedCode
for the ability to call unmanaged code. Associated enumeration: UnmanagedCode
Applies to
Active2 months ago
I am a little bit confused about reading and writing to a serial port. I have a USB device in Linux that uses the FTDI USB serial device converter driver. When I plug it in, it creates: /dev/ttyUSB1.
I thought itd be simple to open and read/write from it in C. I know the baud rate and parity information, but it seems like there is no standard for this?
Am I missing something, or can someone point me in the right direction?
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2 Answers
I wrote this a long time ago (from years 1985-1992, with just a few tweaks since then), and just copy and paste the bits needed into each project.
The values for speed are
B115200
, B230400
, B9600
, B19200
, B38400
, B57600
, B1200
, B2400
, B4800
, etc. The values for parity are 0
(meaning no parity), PARENB|PARODD
(enable parity and use odd), PARENB
(enable parity and use even), PARENB|PARODD|CMSPAR
(mark parity), and PARENB|CMSPAR
(space parity).'Blocking' sets whether a
read()
on the port waits for the specified number of characters to arrive. Setting no blocking means that a read()
returns however many characters are available without waiting for more, up to the buffer limit.Addendum:
CMSPAR
is needed only for choosing mark and space parity, which is uncommon. For most applications, it can be omitted. My header file /usr/include/bits/termios.h
enables definition of CMSPAR
only if the preprocessor symbol __USE_MISC
is defined. That definition occurs (in features.h
) withThe introductory comments of
Gabriel Staples<features.h>
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For demo code that conforms to POSIX standard as described in Setting Terminal Modes Properlyand Serial Programming Guide for POSIX Operating Systems, the following is offered.
It's essentially derived from the other answer, but inaccurate and misleading comments have been corrected.
It's essentially derived from the other answer, but inaccurate and misleading comments have been corrected.
To make the program treat the received data as ASCII codes, compile the program with the symbol DISPLAY_STRING, e.g.
If the received data is ASCII text (rather than binary data) and you want to read it as lines terminated by the newline character, then see this answer for a sample program.
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protected by user405725 Jan 24 '13 at 20:53
C Serial Port Programming Tutorial
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