MAC addresses

Digi programs one MAC address for the Wi-Fi interface during manufacturing of the SOM. This MAC address is stored in the Wi-Fi chip OTP bits, and read from there at the initialization process. A copy of this MAC address is saved in U-Boot environment variable wlanaddr. This is the MAC address used for the wlan0 interface.

The MAC address and serial number of the SOM are encoded in the data matrix on the SOM label.

IP settings

Digi Embedded Yocto defines configuration macros to set some of the most commonly used network interface settings. See Customize the root file system. By default, wlan0 is configured to obtain a DHCP address.

Wireless mode

By default, Digi Embedded Yocto configures the Wi-Fi interface in client infrastructure mode (also known as station), but it is also preconfigured to enable concurrent mode. When using concurrent mode, the interface is shared between all functionalities so overall performance is affected.

Maximum performance is achieved on the physical wlan0 when the Wi-Fi interface is not shared between multiple functionalities. Digi recommends you always use the physical wlan0 interface and only configure virtual interfaces when using concurrent modes.

Power save mode

Power save mode is a power saving mechanism defined in the IEEE 802.11 wireless network standard. A device deactivates its radio during regular periods of inactivity to conserve power and periodically wakes up to check for incoming packets.

Using wireless power save mode has an impact on the response and performance of the wireless interface. Set power save modes according to your specific needs.

The wireless variant of the ConnectCore MP15 SOM that integrates the Murata LBEE5PK2AE-564 wireless chipset allows the following power save modes:

  • Disabled: maximum performance, consumes more energy

  • Power save mode: maximum energy conservation, slower response during wakeup

  • FAST power save mode: moderate energy conservation, moderately delayed wakeup response

By default, the selected power save mode is FAST power save. The difference between FAST power save and power save is dependent on usage. FAST power save mode offers better latency than regular power save mode when traffic happens less often than every DTIM.

For more details about the power save modes, review the following document for the Wireless tool (wl) included in Digi Embedded Yocto.

Set power save mode

The wireless driver allows you to interact with it using standard tools and the wireless tool (wl), which is the default method of interacting with the Murata LBEE5PK2AE-564 wireless chipset. Methods of setting the power save mode include:

Wireless tool (wl)

You can use the wireless tool (wl) to read the current power save mode:

# wl PM
2

One of the following values is returned:

  • 0, for power save disabled

  • 1, for power save mode

  • 2, for FAST power save mode (default)

To set the power save mode using the wireless tool (wl):

# wl PM <power_save_mode>

where <power_save_mode>, is one of the following:

  • 0, for power save disabled

  • 1, for power save mode

  • 2, for FAST power save mode (default)

Wireless driver parameter

To set the power save mode at startup, you must override the wireless driver parameter max_pm using kernel command line parameters. For instance, to disable power save, run the following command:

=> setenv extra_bootargs ${extra_bootargs} brcmfmac.max_pm=0
=> saveenv

NetworkManager

NetworkManager is a daemon that simplifies the configuration and use of network interfaces. It includes a command line tool, nmcli, which you can use to interact with the NetworkManager daemon. You can also configure additional network interface settings by editing /etc/NetworkManager/system-connections/nm.<interface>.