matlab_porthandler

• Description

  PortHandler dependent functions for serial communication.

• Members

  None

• Methods

Methods	Description
portHandle	Initializes parameters for serial port control
openPort	Opens a serial port
closePort	Closes a serial port
clearPort	Refreshes a serial port
setPortName	Sets a device name
getPortName	Gets a device name
setBaudrate	Sets a baudrate
getBaudrate	Gets a baudrate
getBytesAvailable	Checks how many bytes can be read in port buffer
readPort	Reads bytes from port buffer
writePort	Writes bytes to port buffer
setPacketTimeout	Sets timeout
isPacketTimeout	Checks whether communication has been succeeded in timeout

• Enumerator

  None

Method References

portHandler

• Syntax

int portHandler(string port_name)

• Parameters

Parameters	Description
port_name	Port name

• Detailed Description

  The function initializes the parameters for port control. At first, this checks if the port with same device name is set already in the portData pointer struct. If it exists, the function returns the port number as what it has. If not, the function finds any free port, resize portData struct and start to initialize struct members.

openPort

• Syntax

bool openPort(int port_num)

• Parameters

Parameters	Description
port_num	Port number

• Detailed Description

  This function opens the port by setBaudRate function using default baudrate(1M). If the baudrate is needed to be changed to another baudrate value, setBaudRate function should be called again after calling openPort function. When the port succeeds to be opened, this function will return true, and if not, then false.

closePort

• Syntax

void closePort(int port_num)

• Parameters

Parameters	Description
port_num	Port number

• Detailed Description

  This function closes the port by closing the file descriptor.

clearPort

• Syntax

void clearPort(int port_num)

• Parameters

Parameters	Description
port_num	Port number

• Detailed Description

  This function clears the port by flushing the file descriptor.

setPortName

• Syntax

void setPortName(int port_num, string port_name)

• Parameters

Parameters	Description
port_num	Port number
port_name	Port name

• Detailed Description

  This function sets the device name as port_name.

getPortName

• Syntax

string getPortName(int port_num)

• Parameters

Parameters	Description
port_num	Port number

• Detailed Description

  This function returns the device name which the port is using.

setBaudrate

• Syntax

bool setBaudrate(int port_num, int baudrate)

• Parameters

Parameters	Description
port_num	Port number
baudrate	Target baudrate

• Description

  This function converts baudrate to baudrate type value at first. Secondly, it closes the port with closePort function, and opens the port with setupPort function again. If the value of baudrate is not in the compatible baudrate list, the setCustomBaudrate function suggests the baudrate value which is closest of available baudrate value. Finally, it returns false.

getBaudrate

• Syntax

int getBaudrate(int port_num)

• Parameters

Parameters	Description
port_num	Port number

• Description

  This function returns the baudrate value previously set.

getBytesAvailable

• Syntax

int getBytesAvailable(int port_num)

• Parameters

Parameters	Description
port_num	Port number

• Description

  This function checks how much the data can be read, and returns its length.

readPort

• Syntax

int readPort(int port_num, int[] packet, int length)

• Parameters

Parameters	Description
port_num	Port number
packet	The number of data bytes read previously
length	Byte length for read

• Description

  This function gets length byte data from port buffer and returns a number of read data bytes. On end-of-file, 0 is returned, on error it returns -1.

writePort

• Syntax

int writePort(int port_num, int[] packet, int length)

• Parameters

Parameters	Description
port_num	Port number
packet	The number of data bytes to write
length	Byte length for write

• Description

  This function transmits length byte, and returns how much the data was written. On error, it returns -1.

setPacketTimeout

• Syntax

void setPacketTimeout (int port_num, uint16_t packet_length)

• Parameters

Parameters	Description
port_num	Port number
Packet_length	Target byte length for write

• Description

  This function sets the start time when it transmits the packet, and set the timeout of packet transmission to be ready for deciding communication result.

setPacketTimeoutMSec

• Syntax

void setPacketTimeoutMSec (int port_num, double msec)

• Parameters

Parameters	Description
port_num	Port number
msec	Miliseconds

• Description

  This function sets the start time with msec milisecond value when it transmits the packet, and set the timeout of packet transmission to be ready for deciding communication result.

isPacketTimeout

• Syntax

bool isPacketTimeout(int port_num)

• Parameters

Parameters	Description
port_num	Port number

• Description

  This function decides the timeover of packet communication. If the time limit is over, it returns false.