XBee socket

Note This section contains Linux BSP documentation for kernel v4.1. Click here for v4.9 BSP documentation.

The ConnectCore 6UL SBC Pro assembles an XBee socket that allows you to connect any XBee module.

Note See the ConnectCore for i.MX6UL 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

Note 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/OExpander GPIO 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.

Note If your XBee is configured with specific parity and flow control settings, you may have to configure those settings on your serial port.

On one terminal console, read from the serial port:

cat /dev/ttymxc1

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.

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