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alexander-uhde avatar image
alexander-uhde asked

Fixing "dead" Multiplus-II GX / Applying nanopi installer image

Hi guys,

maybe some of you can help me out here.


I am running a Multiplus-II GX and updated to v2.62 (online) recently.

I am also running the node-red-contrib-victron on a separate VM, so I had to change my dbus over tcp settings, as described on github.

With v2.58 and v2.60 this was running fine until now.


Long story short, this time it seems I have messed things up a bit. After changing the configuration in v2.62 I cannot reach my GX any longer over network. The Multiplus-II is reachable via MK3-USB, firmware updates for the Multiplus, changing configuration etc. is working fine this way.


But the GX won't show up. Is it possible to reinstall the GX "from scratch" via the venus-install-sdcard-nanopi.img.zip ?

I put v2.62 of this via BalenaEtcher to a USB stick, as well to a microSDHC (using an USB microSD adaptor for this).

How can I start the reinstallation process? I tried pressing reset button when starting the device, as well as "Push button A", but this does not seem to work.


Is there any other button on the board itself, or some pins I have to shorten?


Right now, I did not detach the nanopi GX to have it on the table (this would mean to completely get the Multiplus off the wall and cables.


Many thanks for your help and have a nice weekend!

Alex

Multiplus-IIVenus OSfirmware update
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alexander-uhde avatar image alexander-uhde commented ·

Edit:

Is there a way to connect via serial console? I did not find a description for the nanopi GX, maybe someone of you has a schematic drawing of the board?

As I said before, at the moment I am still reluctant to detach it completely from the Multiplus to have it "on the table".

Thanks!

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4 Answers
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi, I would advise against rerunning the installer image: you'll also wipe out the serialnumber, wifi wpa-psk key as well as some other data installed in the factory. And, the tricks you tried via USB won't work anyway; you'll need to access the real sdcard slot which is on the invisible side of the nanopi.


Serial console cable, yes thats possible.

I made one the other day, and made a photo of it too: I've added a photo to the serial console section on the root access page:

https://www.victronenergy.com/live/ccgx:root_access#connecting_on_the_serial_console

I have no idea how accessible that is I'm afraid. Hope it is without dismantling the device.




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alexander-uhde avatar image alexander-uhde commented ·

Thanks @mvader, I already had seen this photo, but was not aware that this also refers to the GX in Multiplus-II. So, I will give it a try with serial console. I think there is no way without dismantling it, there is no direct access from the front possible. Thanks again and have a nice one!

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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ alexander-uhde commented ·

you too! Seeing that photo would be rather impossible, I added it only a few minutes ago, and happened to have made it last week. Perhaps you saw another one?


Anyway success!

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alexander-uhde avatar image
alexander-uhde answered ·

Thank you once again, for now everything is up and running. (Including dbus over TCP for node-red :-) )


I messed up the listen command on dbus.


PINs for serial connection were accessible (after some fiddling) even for my fat fingers...

Thanks again for the photo @mvader, I would have gotten no other choice than detaching the whole unit from the wall without this one.

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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·

Glad to hear its fixed!

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alexander-uhde avatar image alexander-uhde mvader (Victron Energy) ♦♦ commented ·

Yip, if you make something idiot-proof, someone will make a better idiot.


Thanks to you and Victron for making these things really robust, my "blind tries" before attaching the serial cable could have really gone worse.


I made an improvement to the Multiplus manual:

2021-02-14-15h25-01.png


Also, for those interested, a short overview of the dbus/ node-red dashboard

2021-02-14-15h37-04.png


Main reason for this:

I was not quite satisfied with the behaviour of "battery life" in these dark winter days.


Of course, with snow on the rather flat solar panels, system would start charging batteries from grid.

Moreover, if a bit sun came out, system would use PV to charge batteries over the adjusted treshold, just to discharge them soon again.


Do not get me wrong, I am not complaining about this- this behaviour is fine if you have a change of "darker" and sunny phases. But in the long german winter, I wanted to adjust this behaviour more to my needs.


Now, if I switch on "Max inverter = PV power -80 watts", PV power will be used primary to power the household. Discharging of the batteries is prevented automatically by this switch.

So I have some sort of "battery life" even in longer phases without PV power without using the grid.


This is my schematics, if anybody is interested, fell free to ask me for sharing:

2021-02-14-15h53-02.png


Have a nice sunday!

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Thomas Manthey avatar image Thomas Manthey alexander-uhde commented ·

Hi Alexander, it's been a few days since your post, but I'm still interested in your system schematic and also the wizard. I am in the process of building my ESS system and am also struggling with Victron's tools.

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alexander-uhde avatar image alexander-uhde Thomas Manthey commented ·
Hi Thomas, if there is anything I can help you with please get back to me.

Btw, are yxou german-speaking?
Have a nice evening,

Alex


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Thomas Manthey avatar image Thomas Manthey alexander-uhde commented ·

Hi Alexander, I speak German, but I was thinking of all the others who don't speak German who are reading this and who might find it helpful if I write in English.

I really have a "configuration problem" in my system right now. As I am doing the mechanical work on the roof, my ESS is without solar cells until now. The inverters don't have a load yet, otherwise the batteries would run down even faster than if only the 3 inverters and the 7 solar controllers were hooked up to it.

I have the problem that my GX device makes a cyclic reset as soon as I connect more than one solar controller via CAN. Since no one has been able to help me with the problem so far, I have continued the system configuration in the direction of the "final expansion" and installed the ESS wizard on all 3 inverters. Except for the fact that the configuration software does not do what it is supposed to (i.e. send the changes to all 3 inverters), it worked as documented and explained in the video. I just had to install the wizard on each inverter individually and then start it.

The problem, for which I have not yet found any documentation either for the Multi or the solar controller, is apparently related to the CAN bus profile. Somewhere I had read that a profile with 250kBit/s had to be selected (but which one). So I played around with the configuration of the CAN profile and found one that runs stably and does not cause a RESET. The profile is called "Oceanvolt 250kBit/s".bildschirmfoto-vom-2023-05-18-23-43-36.png I would be interested to know what this has to do with the Victron solar controllers and the RESET, but it seems to work for now.

If you are interested here is a link to the discussion about this problem: https://community.victronenergy.com/questions/205368/the-gx-unit-in-the-multipluss2-makes-a-cyclic-rese.html?childToView=205419#answer-205419

Many thanks for your help!

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alexander-uhde avatar image
alexander-uhde answered ·

To clarify: I just had to correct the "unluckily pasted" dbus configuration.


There was no need to reinstall the whole system from image.


Just did the update to v2.62 from USB once again (to make sure everything was corrected which I messed up previously), restored the last configuration for Multiplus via VEconfig and MK3-USB and corrected the dbus config for node-red.


Happy for now, let's see if everything still works tomorrow when sun comes up.


Sleep well!

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Simon Fey avatar image
Simon Fey answered ·

This thread helped me a lot to understand how the multiplus-ii-gx is built. I guess I managed to run out of diskspace during flashing a swu-large file and am now stuck with a non-booting unit. The inverter itself however still is operating fine. Since this is a dev-unit I might give it a try to reach the nanopi's SD card slot. @mvader (Victron Energy) I assume venus-install-sdcard-nanopi.img.zip is a bootable SD card image that copies your image to internal flash. Could I just boot an appropriate live system, extract the /data partition, reinstall and restore the /data partition - theoretically?

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