# ODROID-U3

Related articles

- Installation guide

From Arch Linux ARM ODROID-U3 Page:

  "The ODROID-U3 is a very low cost and high performance development platform based on an Exynos 4412 ARM Cortex-A9 Quad Core 1.7GHz CPU. It has 3 USB 2.0 ports and micro HDMI."

Note: Support for the ARM architecture is provided on http://archlinuxarm.org not through posts to the official Arch Linux Forum. Any posts related to ARM specific issues will be promptly closed per the Arch Linux Distribution Support ONLY policy.

## Installation

See the installation instructions at the Arch Linux ARM ODROID-U3 page.

## LEDs

The ODROID-U3 has two LEDs. A red power LED which is always on if power is supplied, and a blue LED which can be configured.

### Blue LED

By default, the blue LED is a heartbeat LED, which flashes when the kernel is running. This can be changed through the `/sys/class/leds/led1/trigger` interface.

#### List available triggers

    # cat /sys/class/leds/led1/trigger

    none mmc0 mmc1 timer oneshot [heartbeat] backlight gpio cpu0 cpu1 cpu2 cpu3 default-on transient

#### Temporary configuration

Replace `TRIGGER` with one of the available triggers. This setting will apply instantly, but be lost upon reboot.

    # echo TRIGGER > /sys/class/leds/led1/trigger

#### Permanent configuration

Replace `TRIGGER` with one of the available triggers. This setting will apply upon reboot.

    /etc/tmpfiles.d/leds.conf

    w /sys/class/leds/led1/trigger - - - - TRIGGER

## CPU Fan

The optional CPU fan can be controlled via the `/sys/devices/platform/odroidu2-fan` interface.

### Fan Mode

    # echo auto > /sys/devices/platform/odroidu2-fan/fan_mode

    # echo manual > /sys/devices/platform/odroidu2-fan/fan_mode

### Fan Speed (Manual Only)

Values range from 0 (0%) to 255 (100%)

    # echo 0 > /sys/devices/platform/odroidu2-fan/pwm_duty

    # echo 255 > /sys/devices/platform/odroidu2-fan/pwm_duty

### Read CPU Temperature

    awk '{printf "%3.1f°C\n", $1/1000}' /sys/class/thermal/thermal_zone0/temp

## See also

- [1] - ODROID-U3 Arch Linux ARM Page
- [2] - ODROID-U3 Hardkernel Product Page

Category:

- ARM architecture