XBee Class Reference

API for the XBee modules. More...

Detailed Description

• ID: xbee
• Name: XBee Serial Module
• Category: wifi
• Manufacturer: sparkfun
• Connection: uart
• Link: https://www.sparkfun.com/products/11215

This is a generic UART driver for use with Digi XBee modules. It was tested with the XBee S1 802.15.4 module and the XBee S6B WiFi module.

It provides basic UART support for sending and receiving data to and from the device. It is controlled by an AT or API command set.

It is connected at 9600 baud by default.

These devices are typically configured using Digi's X-CTU windows software, however it is possible of course to configure them manually using AT commands. See the examples.

XBee Sensor image provided by SparkFun* under CC BY 2.0.

// simple helper function to send a command and wait for a response
void
sendCommand(upm::XBee& sensor, string cmd)
{
    // commands need to be terminated with a carriage return
    cmd += "\r";

    sensor.writeDataStr(cmd);

    string resp;
    while (sensor.dataAvailable(2000)) {
        resp += sensor.readDataStr(1024);
    }

    if (resp.empty()) {
        cerr << "Timed out waiting for response" << endl;
        return;
    }

    resp = sensor.stringCR2LF(resp);
    cout << "Returned (" << resp.size() << " bytes): " << endl;
    cout << resp << endl;
}

int
main(int argc, char** argv)
{
    // Instantiate a XBee Module on UART 0
    upm::XBee sensor(0);

    // Set the baud rate, 9600 baud is the default.
    if (sensor.setBaudRate(9600)) {
        cerr << "Failed to set tty baud rate" << endl;
        return 1;
    }

    printUsage(argv[0]);

    if (argc > 1) {
        // enable command mode
        sensor.commandMode();
        cout << "Sending command line argument (" << argv[1] << ")..." << endl;
        sendCommand(sensor, argv[1]);
    } else {
        // enable command mode
        sensor.commandMode();
        // query the verbose firmware revision
        cout << "Querying verbose firmware revision (ATVL)..." << endl;
        sendCommand(sensor, "ATVL");
        // query the number
        cout << "Querying Serial Number High (ATSH)..." << endl;
        sendCommand(sensor, "ATSH");
        cout << "Querying Serial Number Low (ATSL)..." << endl;
        sendCommand(sensor, "ATSL");

        cout << "Querying address, if set (ATMY)..." << endl;
        sendCommand(sensor, "ATMY");

        // For the XBee WiFi S6B
        // A comprehensive list of commands and command modes is
        // available from the datasheet at:
        // ftp1.digi.com/support/documentation/90002180_L.pdf

        // For the XBee S1
        // A comprehensive list of commands and command modes is
        // available from the datasheet at:
        // http://www.sparkfun.com/datasheets/Wireless/Zigbee/XBee-Datasheet.pdf

        // For the XBee WiFi module:
        // An example using AT commands to connect to an AP, with a
        // private Key using WPA2:

        // Connect to AP with SSID 'mySSID':
        //  ATIDmySSID

        // Provide the private key 'secret':
        //  ATPKsecret

        // Use WPA2 encryption
        //  ATEE2
    }

    return 0;
}

Public Member Functions
	XBee (int uart=XBEE_DEFAULT_UART)
	~XBee ()
bool	dataAvailable (unsigned int millis)
int	readData (char *buffer, unsigned int len)
std::string	readDataStr (int len)
int	writeData (char *buffer, unsigned len)
int	writeDataStr (std::string data)
mraa::Result	setBaudRate (int baud=9600)
bool	commandMode (std::string cmdChars="+++", int guardTimeMS=1000)
std::string	stringCR2LF (std::string str)

Protected Attributes
mraa::Uart	m_uart

Constructor & Destructor Documentation

XBee

(

int

uart = XBEE_DEFAULT_UART

)

XBee object constructor

Parameters

uart	Default UART to use (0 or 1). Default is 0.

~XBee

(

)

XBee object destructor

Member Function Documentation

bool dataAvailable

(

unsigned int

millis

)

Checks to see if there is data available for reading

Parameters

millis

Number of milliseconds to wait; 0 means no waiting

Returns

true if there is data available for reading

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int readData	(	char *	buffer,
		unsigned int	len
	)

Reads any available data into a user-supplied buffer. Note: the call blocks until data is available for reading. Use dataAvailable() to determine whether there is data available beforehand, to avoid blocking.

Parameters

buffer	Buffer to hold the data read
len	Length of the buffer

Returns

Number of bytes read

std::string readDataStr

(

int

len

)

Reads any available data and returns it in a std::string. Note: the call blocks until data is available for reading. Use dataAvailable() to determine whether there is data available beforehand, to avoid blocking.

Parameters

len	Maximum length of the data to be returned

Returns

string containing the data read

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int writeData	(	char *	buffer,
		unsigned	len
	)

Writes the data in the buffer to the device. If you are writing an AT command, be sure to terminate it with a carriage return ()

Parameters

buffer	Buffer to hold the data to write
len	Length of the buffer

Returns

Number of bytes written

int writeDataStr

(

std::string

data

)

Writes the std:string data to the device. If you are writing an AT command, be sure to terminate it with a carriage return ()

Parameters

data	Buffer to write to the device

Returns

Number of bytes written

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mraa::Result setBaudRate

(

int

baud = 9600

)

Sets the baud rate for the device. The default is 9600.

Parameters

baud	Desired baud rate

Returns

true if successful

bool commandMode	(	std::string	cmdChars = "+++",
		int	guardTimeMS = 1000
	)

Attempts to enter AT Command Mode. When Idle, data sent to the device (assuming it is not in API mode) is silently transmitted to the configured destination. Running this command attempts to place the device into command mode, allowing you to send AT commands. Note, after a configurable period of inactivity, the device will exit command mode automatically (default 10 seconds).

Both the cmdChars (+++) and the Guard Time can be configured on the device to different values using AT configuration commands.

Parameters

cmdChars	The command mode characters, default "+++"
guardTimeMS	The number of milliseconds to wait before and after sending the command characters. Default is 1000 (1 second).

Returns

true if successful (received an "OK"), false otherwise

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string stringCR2LF

(

std::string

str

)

This is a convenience method that converts each CR () in a string to a LF (
) and returns it. This is useful for outputting the response to an AT command for instance, which is typically CR terminated.

Parameters

str	The string to convert

Returns

The converted string

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The documentation for this class was generated from the following files:

• src/xbee/xbee.hpp
• src/xbee/xbee.cxx