Hardware Setup

First of all here is the result:

Connection Diagram

Expand Omega Storage with SD card

To install Octoprint on Omega2 you will have to first expand the storage on Omega2+
plug a micro SD card into the Omega2+.

it will show up as /dev/mmcblk0

1. format the SD card to EXT4 (you can skip this if you already have you sd card in EXT4 format)
   install disk utilities:

opkg update
opkg install fdisk e2fsprogs block-mount

• partition the SD card to Linux partition using fdisk
• format SD card

umount /dev/mmcblk0p1
mkfs.ext4 /dev/mmcblk0p1

1. mount SD card
   mount the SD card

umount /dev/mmcblk0p1
mkdir /mnt/SD
mount /dev/mmcblk0p1 /mnt/SD

1. Copy current /overlay directory

tar -C /overlay -cvf - . | tar -C /mnt/SD/ -xf - 
umount /mnt/SD

1. Setting up the /overlay Directory to Automount on Startup

block detect > /etc/config/fstab

• edit /etc/config/fstab
  change option target '/mnt/mmcblk0p1' to option target '/overlay'
  and option enabled '0' to option enabled '1'

reboot

after reboot you can verify if you /overlay is mounted properly by running df
you should see something like this:

/dev/mmcblk0p1         7374776     33328   6947108   0% /overlay

Build Octoprint

1. install required packages
   edit /etc/opkg/distfeeds.conf
   uncomment

src/gz reboot_packages http://downloads.lede-project.org/snapshots/packages/mipsel_24kc/packages

opkg update
opkg install python python-pip unzip
pip install --upgrade setuptools

1. expand /tmp folder on the Omega

mkdir /overlay/tmp
rm -rf /overlay/tmp/*
cp -a /tmp/* /overlay/tmp/
umount /tmp
[ $? -ne 0 ] && {
umount -l /tmp
}
mount /overlay/tmp/ /tmp

1. download and build

cd /root
wget https://github.com/foosel/OctoPrint/archive/1.0.0.zip
unzip 1.0.0.zip
cd OctoPrint-1.0.0
pip install -r requirements.txt

Note: Currently I am only able to get Octoprint 1.0.0 to work

1. Now we need to edit a few files to resolve some compatibility issues.
   TODO: edit the following file

• Unicode is going to cause problem with Python on Omega2. we have to replace the unicode author name to ascii ( Sorry Gina Häußge )

s/Häußge/H\./g
sed -i 's/Häußge/H\./g' /root/OctoPrint-1.0.0/src/octoprint/util/comm.py
sed -i 's/Häußge/H\./g' /root/OctoPrint-1.0.0/src/octoprint/util/virtual.py

• Omega only have one user and that is root. Octoprint does not let you run as root so we have to suppress that

sed -i 's/exit("You should not run OctoPrint as root!")/pass/g' /root/OctoPrint-1.0.0/src/octoprint/server/__init__.py

1. test drive

./run

open up a browser and

Auto start Octoprint at startup

• move OctoPrint to a proper location

mv /root/OctoPrint-1.0.0 /usr/share/OctoPrint

• make symlink to command

ln -s /usr/share/OctoPrint/run /usr/bin/octoprint

edit /etc/rc.local
add the following before exit 0

octoprint &

Lately there has been a lot of discussions about the Omega2+ not being able to boot after unexpected reset. We did some digging and found a solution.

The Problem

In short here is what we have identified as the root of the issue.

• By default both the Omega2+ CPU and Flash memory boots from a 3 Byte address mode
• During boot loader the CPU upgrades both Flash memory and itself to a 4 Byte address mode in order to access higher memory addresses
• During an unexpected reset (brownout) the CPU resets but the memory remains in the 4 Byte address mode.
• The mismatch in the address mode prevent the CPU from booting normally.
• A power cycle at this point will reset the Flash memory back to 3 Byte mode and the system will boot normally

Here is a table summarizing different boot conditions:

Boot State	GPIO 6 (SPI CS1) State	CPU address mode	Flash address mode	Boot Result
Cold boot	Default (pull down)	3 Byte	3 Byte	Success
Hot boot	Default (pull down)	3 Byte	4 Byte	Fail
Cold boot	Pull Up	4 Byte	3 Byte	Fail
Hot boot	Pull Up	4 Byte	4 Byte	Success

The Fix

According to the above table we need to build a solution to have GPIO 6 pulled sown during cold boot and pulled up in at hot boot in order for the system to boot successfully in both conditions. The following circuit does just that.

• During a cold boot GPIO 11 starts as LOW
• GPIO 6 is reads LOW
• During boot the boot loader sets GPIO 11 High (Originally used to provide power to the user pushbutton on Omega2 docks)
• This will charge up the capacitor to 3.3V
• During an unexpected reset or hot boot, the capacitor will temporarily pull GPIO 6 High setting the CPU to boot from a 4 Byte address mode

Please let us know if this setup helps with your situation. We would also like to hear if anyone have came up with a software only solutions. So far we have not yet figured out a way to make the flash memory to cold boot from a 4 Byte address mode.

Here is the Flash memory data sheet for those who are interested in dig deeper MX25L25635E.pdf

Thought you guys would like to see

Thanks for raising this issue. It seems to be related to IPv6 resolution. We are working on a fix.

The Omega2 Dash is a touch screen device based on the Omega2 platform.
This topic is for Omega2 Dash beta testers to track progress and share ideas.

Get Started

Follow instructions on the following GitHub repo to get started on using the Omega2 Dash
https://github.com/OnionIoT/Omega2-Dash

Bug report & Feature suggestions

Use the GitHub Issues page to report bugs or suggest features
https://github.com/OnionIoT/Omega2-Dash/issues

Become Beta Tester

If you would like to participate in beta testing this project you can apply here

Updates

Dec 6 2019 - Official Firmware Available

Official firmware for the Omega2 Dash is now available!

If you have a beta unit, follow these instructions to upgrade to the official firmware:

• Make sure your Omega2 Dash is connected to the internet
• Back up any files that you don't want to lose! The upgrade will erase everything on the filesystem
• Run the following commands:

cd /tmp
wget http://repo.onioniot.com/omega2/images/omega2dash-v0.3.2-b233.bin
sysupgrade -F -n -v omega2dash-v0.3.2-b233.bin

Dec 6 2019

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

• Learn more about the example program here: https://github.com/OnionIoT/Omega2-Dash#littlevgl-example-program
• See the repo here: https://github.com/OnionIoT/lv_example

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!

Dec 5 2019

Displaying image files on the Omega2 Dash. Learn more here

Nov 6 2019

Compiled demo of LittleV Graphics Library with touch input. See how to run it on your Omega2 Dash [here]
(https://github.com/OnionIoT/Omega2-Dash#littlevgl-ui-demo)

Nov 4 2019

Running the Omega's terminal on the display:

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+c to exit.

Package installation writes to flash right away. They should persist even if you just pull the plug on your Omega2. Another possible cause I can think of is you tried to install the packages before your omega2 has fully initialized. Try making sure the orange led stopped flashing after boot.

Can you post some images of the screen after initialization and the command you used to initialize it?

It's back online , have fun inventing

@Andrei-Railean the logic voltage on omega gpio pins are 2.5v +- 10% and the rated current draw is 24mA. It is recommended to use a voltage divider or level shifter when working with 3.3v and 5v devices.

With personal experience, I have connected omega directly with 3.3v I2C devices without seeing any issues.

@T-NT
You are right, it's always a good practice to document all bugs.
https://github.com/OnionIoT/Onion-Console/issues/5

Two new issues are created regarding to the problems.

https://github.com/OnionIoT/Onion-Console/issues/3
https://github.com/OnionIoT/Onion-Console/issues/4

@Xie-Yanbo @Matt-Hudgins connection for the thermal printer is very simple. At the bottom of the printer there are 3 different socket. Use the two pin socket for power and USB port for data. The longer connector socket is not used.

After connecting the thermal printer to Omega's USB port (via expansion dock or mini dock) an ttyUSB* device will show up under the /dev directory on your Omega. At this point you can send any text to the serial device for it to be printed. for example:

echo 'Hello Onion!!!' > /dev/ttyUSB0
echo ''  > /dev/ttyUSB0 #line feed
echo ''  > /dev/ttyUSB0 #line feed
echo ''  > /dev/ttyUSB0 #line feed

you can check out this tutorial

https://onion.io/2bt-omega-bittorrent-machine/

You need to edit the file /etc/config/wireless
Under config wifi-iface sta
set option disabled '0' to option disabled '1'

reboot your omega2+ and it will not try to scan or connect to any WiFi.

@William Scott

We are happy to collaborate in coming up with an automated tests procedure. Doing it publicly here on the community is definitely the way to go. This way more people can contribute of rip the benefit of the test result.

Can you share what test setup you have in mind and specifically what input do you need from Onion side?

Community is back online

Sorry about the oversight. It's fixed now.

@Costas-Costas Yes we are going to sell the breadboard dock on the store as soon as all crowdfunding fulfillment is done.

The Arduino Dock 2 does not come with a USB to serial chip.

The serial connector on the Arduino Dock 2 is connected to ttyS0 on Omega which by difficult is set to be serial terminal at 115200 baud.

You can get to Omega's serial terminal by using an external USB to serial adaptor like this:

@Johannes-Zellner What you have there will not work. You need to decouple the the DC current between the two Omegas.

!!! Works only in theory. Proceed at your own risk !!!

Here you are essentially creating your own transformer to modulate the Ethernet signal. There is no exact requirement for the capacitors and resistors values, however capacitor shouldn't be too big. (for example: 0.1µF and 100Ω should work)

Give it a try if you are adventures or you can always fall back on an ethernet expansion.