Thanks for the fish!

[mboehmer]

Hi guys,

some months ago I implemented an Odroid C2 as readout controller for a scientific instrument.
Lot of people were kind and helped me with some problems with Armbian, especially eMMC and PWM.

 

Today, finally, we managed to have our instrument (two strings with several Odroid C2 and other stuff) deployed.

It is sitting now at 2628m depth in the Pacific Ocean, and will go operational the next days.

 

Here we are... I think I can announce the deepest Odroid so far (cry loud if I'm wrong :) )

In the picture you just can see the Titanium housing with two glass covers attached to the string.

 

Again, thanks for the fish :)

 

Michael

[chwe]

Congratulations! Do you plan to write some updates/purposes of the experiment here in the forum? It's never to learn something new (in case you're allowed to do it).  Maybe we should ask Elon to pick up an Armbian SBC when he shoots the next tesla into space.. 

 

 

[TonyMac32]

3 hours ago, chwe said:

when he shoots the next tesla into space..

 

...So he can miss another planet?

[Da Xue]

That is some bad ass sh*t.

[guidol]

6 hours ago, mboehmer said:

It is sitting now at 2628m depth in the Pacific Ocean, and will go operational the next days.

 

how do you receive GPS in 2628m depth? or is this a compas?

[mboehmer]

2 hours ago, guidol said:

 

how do you receive GPS in 2628m depth? or is this a compas?

No compass or GPS. You see a picture from the videostream taken by the ROV, which made optical inspection after deployment and attached cablings afterwards. The ROV uses GPS coordinates from the mother ship, and corrections made by sonar system.

The module itself carries no GPS, as obviously, there is no signal down there - nevertheless, we use a compass chip (MC6470) to measure orientation inside gravitational field or earth and hopefully also inside magnetic field (depends on how well that works inside the Titanium housing).

[Neil Armstrong]

@mboehmer great job ! I’m happy it’s finally working !

[mboehmer]

Short update... we seem to have kind of network trouble with the 1GbE ethernet port of Odroid C2.

It seems to "die" after some time, more or less the same way on all five Odroids.

Is there any known issue with the network kernel driver?

 

Still investigating the circumstances, and can provide more debugging info if needed.

 

Any help/hint is appreciated.

[umiddelb]

Which kernel version are you using?

 

[mboehmer]

Hi guys,

 

after some rest we will soon start a new development (yet another deep sea installation).

Just wanted to warn you, I will come up with some silly questions again for sure

Especially about the changes made last time on kernel, like device tree, eMMC issues, and UART speed for kernel console.

 

So far, Michael

[mboehmer]

On 7/21/2018 at 9:06 AM, umiddelb said:

Which kernel version are you using?

 

Issue solved, btw. A wrong capacitor was mounted on our power supply assembly (SMD, unmarked).

We got a small dip on +5V rail, disconnecting the USB ethernet adaptor. It was reenumerated, but in brown out, so the USB interface showed up again, but the network part was dead.

Changing the capacitor, and adding some smart power regulation for another switched load fixed the issue.

[chwe]

keep on rocking. I assume it's part of a research program? Is it planed to release some information what you try to discover or is it a private funded not public project?

[mboehmer]

It is a research program, one of our professors from TU Muenchen cooperates with the Canadians (who operate the sub sea infrastructure).

The goal of this setup was to measure water quality in North Pacific (more specific, this special site) by deploying some light emitters and light detectors on two strings.

We want to learn about bioluminescence and radioactivity induced light, which both are kind of noise for the measurements intended later.

Let's say it like this: it's dark there, really, you have a perfect stable temperature, and it's easier to get things there (and back again) than going for deep holes in ice.

 

Moreover, we had to learn all necessary things about sub sea technics in a short period of time, including deployment technis (thanks to one guy supporting us, we made the job).

 

The setup is still operational (which I call success), and with some luck we will extend it with a third string next year, including some Odroid C2 based setups and (as we go for real fibre that time instead of good ol' copper lines) some more sophisticated electronics.

 

As soon as our paper is published, I can give more details (while I "just" did the electronics, there will be some more physics included )

[mboehmer]

Hi guys,

 

finally, paper is finished, and for anyone interested it can be found here on the arXiv site

Be warned, it concentrates on the physics, not the electronics

 

Michael