@Luciano-S @WereCatf told here that the devs of the Omega2 forgot to enable CONFIG_DEVMEM in the newer firmware. The last working one is 0.1.6 b137
So my guess is that it is fixed in the next release if it is indeed just a forgotten flag.
Some sample code for driving the MAX7219 from the Arduino can be found at
@Kit-Bishop just bought this MAX7219EWG module and was able to drive it using Arduino (using the LedControl library). Now planning to play around with it using your library. Need help to check if the below table wiring is correct (not sure about the CS)
Hi @simon-jones you mentioned that you are using a Power Dock? The Power Dock does not include a USB-to-Serial chip meaning that you will not be able to connect via serial, as mentioned in the Power Dock wiki. Please use SSH instead.
At a guess, you don't have permission to the /dev/ttyUSB0 device. Assuming you're on Ubuntu (or probably Debian or others) if you do
ls -l /dev/ttyUSB0
you should see something like:
crw-rw---- 1 root dialout 188, 0 Dec 9 21:25 /dev/ttyUSB0
(note that you will likely have to have the dock plugged in for this device to exist!)
Feel free to skip this next bit if you already know Unix permissions!
Here's a quick explanation of this if you don't know what it means. The first bit (crw etc.) is the permissions on the device. The c at the beginning indicates that this is a special 'file' type connected to a device. (Don't worry about that bit.) The next sets of characters show what the permissions to this device are: r for read, w for write, and x for executing as a program. These are in three sections, one for the owner of the device, one for the group of users that own the device, and one for everyone else. In this case, rw-rw---- means that the owner has read and write permission (but not execute), the group does as well, and everyone else has nothing at all.
After the permissions are the name of the owner and the group that owns the device. In this case, 'root' owns it and the 'dialout' group is the group. Since you are neither root nor in the 'dialout' group by default, you fall into that other category with no permission to access the device.
Now the solution!
There are a few ways you can deal with this. One is to use 'sudo' when launching screen:
sudo screen /dev/ttyUSB0 115200
This will execute screen as the root user, meaning you are now the 'owner' of the file. If you're okay with doing this every time, you're all set.
Another thing you could do is to make yourself a member of the 'dialout' group:
sudo usermod -a -G dialout [your user name]
This will add you to the dialout group and give you permission. You will need to log out and back in first before this will work though.
Hi @Thomas-Ayotte, I think it's definitely possible to get debian to the Omega, it's just that nobody has done it. Since the Omega has only 16MB of flash storage, you are going to need to strip a lot (probably most) of features of Debian to make it fit. This means stripping many features that make Debian Debian. If you want to retain the "feel" of Debian and still be able to fit it into the Omega, then it becomes a much more difficult problem.
My suggestion would be for you to try out OpenWRT. I've used both distributions in the past, and they are really not that different. You should be able to accomplish most tasks from OpenWRT using similar command syntax than in Debian, so it's just a matter of learning which OpenWRT command maps to which Debian command (i.e. opkg maps to apt-get).
I have the same issue and I'm currently making a new topic for it (Lazar asked me to do this after I first posted to the ticketing system).
A friend and I managed to hack into the omega by interupting the boot sequence an replacing init with sh. Then we were able to see the crypted password, wich in turn googled to the string '5up'. This seems to be the OpenWRT standard root password.