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Onion Omega2 Dash IoT Computer
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Onion Omega2 Dash IoT Computer - a touchscreen device based on the Omega2

front back

Bring-Up Guide

Official firmware for the Omega2 Dash is available: omega2dash-v0.3.2-b233.bin

Steps to flash your Omega2 Dash:

  • Download the omega2dash-v0.3.2-b233.bin firmware to the /tmp directory on your Omega2 Dash
  • Use sysupgrade to install the firmware: sysupgrade -n -v /tmp/omega2dash-v0.3.2-b233.bin
    • If you're upgrading from the old test firmware, you will probably have to add a -F flag to the sysupgrade command
  • Wait until it reboots

This firmware has a kernel driver for the ILI9341 TFT driver and enables a framebuffer device, /dev/fb0.

Doing Things with the Omega2 Dash

Backlight Control

Backlight is controlled by GPIO21 (PWM Channel 3)

  • 100% duty cycle = min brightness
  • 0% duty cycle = max brightness
omega2-ctrl gpiomux set uart2 pwm23
onion pwm 3 50 120

omega2-ctrl gpiomux set uart2 pwm23
onion pwm 3 0 120

The second-last argument controls the duty cycle.

Touch Driver

Using XPT7603 controller, connected to Omega via I2C

  • I2C Address: 0x48
  • Interrupt pin: GPIO14

Shell commands to test touch input:

#read X
i2cget -y 0 0x48 0x88 w

#read Y
i2cget -y 0 0x48 0x98 w

Controlling the Display

By default, the framebuffer is connected to the /dev/tty1 virtual device.

Try echoing to this tty and you'll see the contents printed on the display!

echo "hello from the Omega2 Dash" > /dev/tty1

The blinking cursor on the display can be disabled:

echo 0 > /sys/class/graphics/fbcon/cursor_blink

To enable it again, just echo a 1 instead.

The orientation of the display can also be changed:

echo 1 > /sys/class/graphics/fbcon/rotate

Valid options are 0, 1, 2, and 3


Terminal Demo

Running the Omega's terminal on the display:

terminal demo gif

  • Run sh > /dev/tty0 on your Omega2 Dash. Everything you type from then on will show up on the display and not in your terminal window
  • Hit ctrl+d to exit

Displaying png & jpg Images

Display image files:

onion logomap

Steps to display images on your Omega2 Dash:

  • First install the fbi package: opkg update ; opkg install fbi
    • This only needs to be done once
  • Transfer image files to the Omega. Supported file types are png, jpg
  • Display the images by running fbi -d /dev/fb0 -notty -nocomments --noverbose <PATH TO IMAGE FILE>

For example: fbi -d /dev/fb0 -notty -nocomments --noverbose /root/map.png

The fbi program is really flexible, try running it with multiple files and see what happens!

LittleVGL UI Demo

Demo of a touch-enabled GUI made with LittleV Graphics Library:

littlev demo gif

Steps to run on your Omega2 Dash:

LittleVGL Example Program

We've put together an program that can serve as the starting for Omega2 Dash programs using the LittleV Graphics Library. See the repo here:

Out of the box it supports:

  • The Linux Framebuffer - will draw to the Omega2 Dash display
  • The XPT7603 touch input device on the Omega2 Dash
  • A makefile and instructions to build it as an OpenWRT package
  • A small demo

Use this to get started with your own lvgl programs!


Steps to run the existing example on your Omega2 Dash:

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