The ConnectCore 6UL SBC Pro assembles an XBee socket that allows you to connect a through-hole XBee module.

See the ConnectCore 6UL SBC Pro Hardware Reference Manual for the XBee socket pin-out description.

Device tree bindings and customization

The XBee module is interfaced through two interfaces:

  • UART2 of the i.MX6UL CPU.UART2 is configured (4-wires) on the ConnectCore 6UL SBC Pro device tree include file and enabled by default on the ConnectCore 6UL SBC Pro device tree file

  • USBH4 bus

    This bus is also routed to the USB expansion connector. If using the XBee via USB, make sure you don’t connect another device via the expansion connector.

The following XBee lines are connected to I/O Expander GPIOs:

  • XBEE_RSTN: Connected to I/O Expander IO7

  • XBEE_SLP_RQ: Connected to I/O Expander IO9

  • XBEE_ON_SLP_N: Connected to I/O Expander IO11

  • XBEE_IDENT: Connected to I/O Expander IO33

See Universal Asynchronous Receiver/Transmitter (UART), Universal Serial Bus (USB), and I/O Expander for more information about these interfaces.

The XBee does not require a specific driver. Its entry on the device tree defines the GPIO used as the reset line. This is used to reset the XBee to a known state when booting Linux:

ConnectCore 6UL SBC Pro device tree
xbee {
	digi,reset-gpio = <&mca_ioexp_gpio 7 GPIO_ACTIVE_HIGH>;
}

User space

Basic validation

You can use the serial port to check that the XBee module is connected correctly.

  1. Configure the serial port to match the configured speed of the XBee. For example:

    ~# stty -F /dev/ttymxc1 speed 9600 raw
    If your XBee is configured with specific parity and flow control settings, you may have to configure those settings on your serial port.

  2. On one terminal console, read from the serial port:

    ~# cat /dev/ttymxc1

  3. On a different terminal console, write +++ to the serial port:

    ~# echo -n +++ > /dev/ttymxc1

When the connection is successful, the console displays an OK response on the terminal that is reading the port.

See the XBee ANSI C Library for additional information on advanced use of XBee modules.