View source for CL-SOM-iMX8X: Yocto Linux: How-To Guide

=Wireless interfaces= 
{{note|The operations below requires '''root''' access.}}
CL-SOM-iMX8X features certified 802.11ac Wi-Fi and Bluetooth 4.2 interfaces (Intel 8265 chipset).
==Wi-Fi==
Before working with Wi-Fi, please, ensure that Wi-Fi antenna is connected.<br>
For hardware setup and Wi-Fi antenna connection instructions please refer to [[CL-SOM-iMX8X: Evaluation Kit: Hardware Guide#Wireless | evaluation kit hardware guide]].<br>
To start using Wi-Fi insert your network credentials into the following file:<br>
<pre>
/etc/wpa_supplicant.conf
</pre>

Insert the network name into '''ssid''' field, password into '''psk''' field and key into the key_mgmt field (if your network uses key management).<br>
The file should have the following content:
<pre>
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=0
update_config=1
  network={
      ssid="<the name of your internet acces point>"
      key_mgmt=WPA-PSK
      psk="<the password of your internet access point>"
   }
</pre>

Execute the following commands to connect to the network.
<pre>
root@cl-som-imx8x:~# wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf -D nl80211
root@cl-som-imx8x:~# udhcpc -i wlan0
</pre>

==Bluetooth==
Before working with Bluetooth, please, ensure that Wi-Fi antenna is connected.<br>
For hardware setup and Bluetooth antenna connection instructions please refer to  [[CL-SOM-iMX8X: Evaluation Kit: Hardware Guide#Wireless | evaluation kit hardware guide]].

To start '''bluetoothctl''' use the following command:
<pre>
bluetoothctl
</pre>

To start the scan process use the following commands:
<pre>
[bluetooth]# default-agent
[bluetooth]# power on
[bluetooth]# scan on
</pre>

Bluetooth device should be turned on and visible. Its MAC-adress and name should appear in '''bluetoothctl''' in following format:
<pre>
[CHG] Device AA:BB:CC:DD:EE:FF Name: Device_Name
</pre>

To pair with the Bluetooth device use the following command:
<pre>
pair AA:BB:CC:DD:EE:FF
</pre>

Where '''AA:BB:CC:DD:EE:FF''' is MAC-adress of the Bluetooth device.

To quit '''bluetoothctl''' use the following command:
<pre>
[Device_Name]# quit
</pre>

=CPU frequency=
{{note|The operations below requires '''root''' access.}}
CPU frequency can be changed in one of the following methods:
==Changing the scaling governor==
Execute the following command to change scaling governor:
<pre>
echo performance > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
</pre>
Where '''perfomance''' is name of the scaling governor.<br>

Execute the following command to see available scaling governors:
<pre>
cat /sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors
</pre>

Execute the following command to see current scaling governor:
<pre>
cat /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
</pre>

==Changing CPU frequency==
{{note|CPU frequency can be changed only when '''userspace''' scaling governor is enabled.}}
Execute the following command to change scaling governor to userspace:
<pre>
echo userspace > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
</pre>

Execute the following command to see available CPU frequencies:
<pre>
cat /sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies
</pre>

Execute the following command to select the CPU frequency 1.2GHz:
<pre>
echo 1200000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed
</pre>

Execute the following command to see current CPU frequency:
<pre>
cat /sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq
</pre>

=CPU temperature=
Execute the following command to see current CPU temperature:
<pre>
cat /sys/class/thermal/thermal_zone0/temp
</pre>

=RTC=
{{note|The operations below requires '''root''' access.}}
Execute the following command to set the date and write it into the RTC do the following:
<pre>
root@cl-som-imx8x:~# date -s "12 SEP 2019 10:00:00"
Thu Sep 12 10:00:00 UTC 2019
root@cl-som-imx8x:~# /sbin/hwclock --systohc
root@cl-som-imx8x:~# hwclock -w
</pre>

Execute the following command to access the RTC time and date run:
<pre>
root@cl-som-imx8x:~# hwclock
Thu Sep 12 10:00:48 2019  0.000000 seconds
</pre>

=See Also=
*[[CL-SOM-iMX8X: Evaluation Kit: Getting Started | CL-SOM-iMX8X:Evaluation Kit: Getting Started]] <br>
*[[CL-SOM-iMX8X: Evaluation Kit: Hardware Guide | CL-SOM-iMX8X: Evaluation Kit: Hardware Guide]]<br>

[[Category:Yocto]]
[[Category:CL-SOM-iMX8X]]