Odroid xu4 setup with debian stretch for digilent waveforms

[Doug Coulter]

I wanted a somewhat disposable computer to run the Digilent Analog Discovery at the fusor where things are a bit likely to eat a lightning bolt and die...
My raspberry pi 3 (didn't try the b+) had issues with powering the AD2, and adding a power supply to its barrel jack didn't help, so...
I had a couple of these Odroids laying around. I hadn't built them into infrastructure as who knows how long they'll be available? They're nice machines, and in the SBC category, I'd rate them between "Fast" and "Blazing fast" when used with EMMC. You'd think you were on a real computer.

Part of this is probably due to the work of this fellow making a debian distro with almost no fat - this thing boots like the wind, even compared to my "big and fast" boxes. As they say "just read the directions". I added chromium as directed here and it's great too.

This was so stripped down it didn't even have the usual direcories under /home/user, so I added ~/bin and ~/Public, and samba (via synaptic) and created a share of Public to make moving things around easier. I added my LANDNS (tellem and tellme) along with their .service files for systemD (yuck but it works).

Tightvnc gave me some fits at first, it either didn't want to autostart, or it would start and fail (and eat all the machine resources) or just not work (can't get name error).
While ssh -X works...I like VNC and have a ton of machines on my remina setup on my main boxes to admin or just run all the other stuff without having to break pose on the couch. So... this is what it took to make it work on Odroid-Stretch-Mate, the relevant text being:

Can you try removing everything from ~/.vnc/xstartup.turbovnc except:

unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
exec /usr/bin/mate-session

? This will ensure that MATE is started directly rather than through the xinitrc mechanism. Perhaps it is the latter mechanism that it causing problems.
Other than the filename being a little different.

My own notes look like this:

Code: Select all

some trickery required to get tightvnc going on odroid-mate

A destop file needs to be in ~/.config/autostart and look like this:

[Desktop Entry]
Type=Application
Name=tightvnc
Comment=vnc server
Exec=vncserver :1
Startup Notify=false

We also have to change the ~/.vnc/xstartup to:

#!/bin/sh

unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
exec /usr/bin/mate-session


Board doesn't allow .txt files and it's driving me nuts. Donovan! You're our only hope!

After adding samba, and ~/Public, editing /etc/samba/smb.conf (no I don't make these crazy naming conventions) to add the share at the end looks like this:

Code: Select all

[pub]
comment = Public on LittleO
path = /home/odoid/Public
guest ok = yes
browseable = yes
writeable = yes
read only = no

Gives you a share, subject to the usual issues with cifs and friends sometimes not being able to find it's own anatomy with both hands or pour pee out of a boot - and then being fine the next time everyone reboots. I don't know why I've not changed everything to NFS yet...lazy I guess.

This lashup runs Digilent's "Waveforms" software to drive the Analog Discovery2 as well as any other linux box I own, and through VNC at that, so I can be safely distant from things in the lab while doing tests with it. I can either use a wifi dongle (plan A) or plug it into the switch at the fusorPi that's fiber isolated from the rest of the network if there's too much noise for wifi to fly.

I can put up an image if anyone wants, or you can send me a self-addressed stamped SD card 16 gigs or bigger...Those new class A1 (on top of UHS 1 or 10) really do sing compared to the old days, but they're still SD cards. The EMMC on the odroid makes a ton of difference.

A messy desk...dunno about my mind

I used the big passive heatsink for the XU4, but had the fans from the other version, and put those on top - it's somewhat overkill, but let me tell you, there is NO throttling ever. The fans are whiney - but this alerted me to various config problems that were eating resources and making the fan run when there shouldn't have been a need.

Note: These do actually need the 4 amp power supply they recommend. I did half of this with a jerry rigged 2 amp one, but started to have "issues"...and all went away on the big supply.

[Doug Coulter]

Screenshot of this in action - from my NUC couch computer, over VNC.

Running Waveforms on a series tuned circuit that looks like the fusor with a series L and no ions.

[Donovan Ready]

On it, boss. Text files are now allowed.

Edit: It's already enabled in the ACP.

No problem. Curious.

blocklist.txt

(271 Bytes) Downloaded 280 times

[Doug Coulter]

Thanks! Did I have a senior moment and just forget? I know I tried some time ago but it failed when I tested IIRC. Of course, they kinda crash and reboot us around once a month. Not that when I call support and it's down they admit this.

That's some blocklist. All Russians? My ISP told me they pretty much block all China, but not so as I would notice doing biz with the various cheapo vendors there.
At any rate, here I use a few adblockers in tandem and it seems good - one doesn't click on things at random around here anyway. Seems ads are the main vector for badware these days. Glad I'm not trying to advertise!

[Donovan Ready]

That was just a snippet. My full blocklist is 7175 lines.

Want it?

[Doug Coulter]

No need at present, I'm not doing anything directly internet facing other than this board and someone else handles that (usually fairly well).
So, Russians first?
I once hired some Russian guys to help with Musicad - some of the first nonlinear audio editing software. They were tremendously good.
It was hard to get their pay to them due to various obstacles both governments and banks put in the way (even back then) but they were extremely grateful
for a few k$ for what would have been 10's of k$ had anyone in local been given the same job. Hard currency went a long way for them. They said they bought a car and upgraded their machines.

And they did what would have been a couple month job in a few days. I never did find out if it was a team or just one guy. Don't care, it
was good code, and as Linus would say "in good taste".

Their code added tracking presets to real time changes to special effects (we were the first to allow realtime previews of efx settings on the selected audio) - time varying setting presets, which could be kept as a timeline, or as a snapshot if you thought you got it just so for an instant. To around 40 varying-dimension special effects, including audio ray tracing reverb in complex room shapes with moving sources and microphones. Crazy stuff. I'd dig it up and publish again, but thread 3 was all about adapting to mmsystem16 in win 9x - or using my TMS320C31 DSP ISA card, and it's not going to be much use to anyone at this point. All DevStudio junk. Even our eyes glazed over on that job after writing that crazy code with 3 threads, no semaphores, no conflicts, smooth realtime audio - on machines that today would be a joke (486 class). This worked on some tens of efx that were written by 3 different people with their own styles, the Ruskies came to kick butt and chew gum but were all outa gum.

Given that display of stellar skill, I sure wouldn't want those guys on the "other side".

World's first really good full duplex soundcard - my design. (and how I retired a couple decades earlier than most)

[Donovan Ready]

Actually, China, then Russia. After that, Israel and Romania, Brazil, Saudi Arabia and Iran... Weird TOR exit routers, Amazon, NSA, DoD...Lord knows what else without reading through the list.

Most because of childish w00t w00t attacks that are so freakin' old that the kids stumbling through the script are younger. A serious number are because of searches for vulnerabilities in phpadmin, all of which I have hardened against.

Hell, I run "clear;tail -f -n 7 /var/log/apache2/access.log" in a terminal dedicated to the server, so I see everything that goes by. Only port 80 is open,makes it easier..

[Doug Coulter]

Ha! I guess we can be a little OT in our own home.
And our "security apparatus" wants to insist that attribution is no biggie. Um...I once got paid for showing them just how stupid that was, maybe a decade ago.

Yeah, I think of this Dan Tentler talk when I think of the kiddies. They think this is so easy...I had a guy the other day want me to spend a few days teaching him so he could reap all those big bug bounties...yeah, right. Not that these guys don't make mistakes - even with their teams of > $100k/yr programmers and architects, but...

It's clear there's plenty of stupid to go around...on all sides.
https://youtu.be/5xJXJ9pTihM