Embedded SBC MBa8MP-RAS314 - Armbian Linux BSP documentation

Play Audio on MBa8MP-RAS314

A simple test sound can be played with the commandline tool speaker-test.
Headphones or active speakers have to be connected to X3 on MBa8MP-RAS314.

speaker-test --channels 2 --test wav

You can also play your own audio files using aplay

aplay <file>

e.g.

aplay test.wav

arecord -f cd test.wav

The MBa8MP-RAS314 supports DVFS (dynamic voltage and frequency scaling, by default the governor schedutil is set. Governors are power schemes for the CPU. Only one may be active at a time.

You can change the actual governor with the following command:

cpufreq-set -g <governor>
(e.g. cpufreq-set -g performance)

Disable CPU Core temporarily

At runtime it is possible to disable multiple CPU cores via the Linux sysfs. On a system that has four CPU cores, the maximum of three cores can be disabled. To disable the a CPU core value 0 must be written to the CPU core specific file /sys/devices/system/cpu/cpu<N>/online where <N> is the number of the Core, the counting starts at zero.
e.g. disable CPU core 4:

echo 0 > /sys/devices/system/cpu/cpu3/online

To check which CPU core(s) are currently enabled the following command can be used:

grep "processor" /proc/cpuinfo

The CPU core can be enabled again by writing the value 1 to /sys/devices/system/cpu/cpu<N>/online.

e.g. enable CPU core 4:

echo 1 > /sys/devices/system/cpu/cpu3/online

setenv addcpu maxcpus=${cpu_num}

setenv cpu_num 2

The MBa8MP-RAS314 provides two Gigabit Ethernet interfaces.

setenv ipaddr <ipaddr> 
(e.g.: setenv ipaddr 192.168.100.111)
setenv netmask <netmask> 
(e.g.: setenv netmask 255.255.255.0)

ip link set eth0 up

ip link set eth0 down

ip addr show eth0

 
ip -s link show eth0 

ip addr add 192.168.1.100/24 dev eth0

ip -s link

ip route add default via 192.168.1.1 dev eth0

dhclient 

There are two ways to connect to a Wi-Fi network. Graphically or via the command line.

Using Wi-Fi on the MBa8MP-RAS314 via the command line and connecting it to a wireless network is done using nmcli, which is the command line utility for the NetworkManager and a common Linux application for identifying and configuring Internet connections.

First check the status of your network interfaces:

nmcli dev status

If you are not sure whether your Wi-Fi device is enabled or not, you can check it with this command:

nmcli radio wifi

If you want to enable or disable your Wi-Fi, use the following command:

nmcli radio wifi on

nmcli radio wifi off

If you don't know the name of your Wi-Fi network yet, you can view all available connections with the following command:

nmcli dev wifi list

If you know the name and password of your network, you can use the following command to connect to it:

sudo nmcli --ask dev wifi connect your-Wi-Fi

Enter the name of your network at “your-Wi-Fi”. After issuing the command, you will be prompted to enter your password.

Running a GPU benchmark requires a display (HDMI or LVDS) Please keep in mind to set the devicetree properly if LVDS is used.

The benchmark tools are not included in the standard image configuration. In order to use them, they have to be downloaded via APT package manager.

sudo apt install kmscube

or

sudo apt install glmark2-es-drm

The benchmark can be started by using the following terminal commands:

 kmscube 

 glmark2-es2-drm 

HDMI is enabled by default on all Armbian images for the MBa8MP-RAS314 board, no further configuration is required.

TQ offers an optional LVDS Display kit for the MBa8MP-RAS314. To activate LVDS including the display configuration, the devicetree imx8mp-tqma8mpql-mba8mp-ras314-lvds.dtb has to be set in /boot/extlinux/extlinux.conf in the line beginning with “fdt”

fdt /boot/dtb/freescale/imx8mp-tqma8mpql-mba8mp-ras314-lvds.dtb

To load the LVDS devicetree restart the system.

Set the hardware clock to the actual time and date use the following commands:

date -s MMDDhhmmCCYY.ss
hwclock -w

The MBa8MP-RAS314 has one SPI interface, it is routed to header X1 and can be tested with a loopback test.

echo -n -e "\x01\x0F" | spi-pipe -d <spi interface> -s 10000000 | hexdump
(e.g. echo -n -e "\x01\x0F" | spi-pipe -d /dev/spidev3.0 -s 10000000 | hexdump)

The MBa8MP-RAS314 has one temperature sensor, which is located on the TQMa8MPxL SOM.

Read TQMa8MPxL Temperature Sensor

cat /sys/devices/platform/soc@0/30800000.bus/30a20000.i2c/i2c-0/0-000001b/hwmon/hwmon2/temp1_in

Read CPU internal Temperature Sensor
The i.MX8MPxL CPU has an internal TMU that supports two thermal zones, both can be read by the commands below:

Thermal zone0

cat /sys/devices/virtual/thermal/thermal_zone0/temp

Thermal zone1

cat /sys/devices/virtual/thermal/thermal_zone1/temp

With lsusb you can see all connected usb devices. To mount a partition of an usb stick you can excute mount /dev/<partition> <mount dir> (e.g. mount /dev/sdb1 /mnt). This will mount the first partition of sdb to /mnt. To unmount the device execute umount <mount dir> (e.g. umount /mnt).

The MBa8MP-RAS314 has two user LEDs, the behavior of these LEDs can be selected by several triggers.

The user LED's are located in /sys/devices/platform/gpio-leds/leds/.
To change the behaviour of a specific LED, the value in the file trigger must be overwritten.

The following values are valid:

For example set the trigger of “green:” to heartbeat

echo heartbeat > green: