CommandParser

Parses the serial input for commands. More...

#include <CommandParser.h>

Public Types
enum	COMMANDS {   WAITING , PAN_TILT , PAN_TILT_OFFSET , HOME ,   ERROR }

Public Member Functions
uint8_t	parse ()
	Reads serial input and checks for commands. More...
char *	getCommand ()
	Get the command buffer. More...

Static Public Member Functions
static CommandParser *	initialize ()
	Creates a new instance of the class if there isn't one. More...

Private Member Functions
	CommandParser ()
	Constructor of the class.
uint8_t	createBuffer ()
	Checks the serial port for input if the character is a line feed(LF) or carriage return(CR) the end of a command is signaled. More...
uint8_t	checkCommand ()
	Checks the buffer for a command Checks the buffer to see if there is a known command. If there isn't one, returns a command error. More...

Private Attributes
char	ch
	Last read character from serial port.
char	buf [255]
	All characters read from serial port.
uint8_t	bufIndex
	Location index off the last character placed in the buffer.

Static Private Attributes
static CommandParser *	instance = 0
	pointer to current used instance

Detailed Description

Parses the serial input for commands.

Member Enumeration Documentation

COMMANDS

enum CommandParser::COMMANDS

Parser commands

Enumerator
WAITING	Indicates parser is waiting for a command ('/n' or '/r' character)
PAN_TILT	Indicates a Pan and Tilt command.
PAN_TILT_OFFSET	Indicates a Pan and Tilt offset command.
HOME	Indicates a Home command.
ERROR	Indicates that the command is not recognized.

                 {
        WAITING,            
        PAN_TILT,           
        PAN_TILT_OFFSET,    
        HOME,               
        ERROR               
    };

Member Function Documentation

createBuffer()

uint8_t CommandParser::createBuffer ( )

private

Checks the serial port for input if the character is a line feed(LF) or carriage return(CR) the end of a command is signaled.

Returns

int:

• -1: No serial.available
• 0: Command not ended
• 1: Command ended

                                    {
    if (Serial.available() > 0) {
        ch = Serial.read();
        if (ch != '\n' && ch != '\r') {
            buf[bufIndex] = ch;
            bufIndex++;
            return 0; // Add to buffer
        }
        else {
            //string termination
            buf[bufIndex] = '\0';
            bufIndex = 0;
            return  1; // Buffer full
        }
    }
    return -1;
}

Here is the caller graph for this function:

checkCommand()

uint8_t CommandParser::checkCommand ( )

private

Checks the buffer for a command Checks the buffer to see if there is a known command. If there isn't one, returns a command error.

Returns

uint8_t: index of a command or error

See also

COMMANDS

                                    {
    
    if (0 == strncmp("PTO", buf, 3)) {
        return COMMANDS::PAN_TILT_OFFSET;
    }
 
    if (0 == strncmp(buf, "PT", 2)) {
        return COMMANDS::PAN_TILT;
    }
 
    if (0 == strncmp("Ho", buf, 2)) {
        return COMMANDS::HOME;
    }
 
    return COMMANDS::ERROR;
}

Here is the caller graph for this function:

initialize()

CommandParser * CommandParser::initialize ( )

static

Creates a new instance of the class if there isn't one.

Note

only one instance can excist because of the serial port

Returns

: CommandParser: Pointer to object instance

                                         {
    if (0 == instance) {
        instance = new CommandParser;
    }
    else {
        Serial.println("ERROR: CommandParser is already initialized");
    }
 
    return instance;
}

Here is the call graph for this function:

parse()

uint8_t CommandParser::parse

(

)

Reads serial input and checks for commands.

See also

createBuffer()

checkCommand()

Returns

index of a command or error

See also

COMMANDS

                             {
    if (1 == createBuffer()) {
        return checkCommand();
    }
 
    return 0;
}

Here is the call graph for this function:

getCommand()

char * CommandParser::getCommand

(

)

Get the command buffer.

Returns

Pointer to the command buffer

                                {
    return buf;
}