greg-johnson avatar image
greg-johnson asked

SmartShunt protocol

I have a Cerbo GX, SmartSolar, SmartShunt, and Multi. Using VE.Direct, I'm trying to get the MPPT and shunt into the cerbo, with no success.

My cables follow the guidelines in the "VE.Direct Protocol" PDF found at (this information should be in the manual, I believe):


ie this is a null modem cable with a connected power pin.

I can see that the table in that PDF also shows the fields that are transmitted over the line by each device, but only details the BMV 600, BMV 700, MPPT, and Phoenix Inverter, Charger. It does not include the SmartShunt.

Should I expect that the SmartShunt implements the BMV700 values?

As my Cerbo does not appear to see either the MPPT nor SmartShunt, I will put a scope on the TX pin tonight to verify output activity (I understand that at least the MPPT has the potential to re-use the TX/RX pins as digital outputs for PWM/charger control - that to me is frustrating that the design didn't just add two extra pins to provide that instead of multiplexing them)

I have enabled root access on the Cerbo, but I'm not sure where to look to find if serial activity is being detected. I also downloaded the VenusOS code from github to see if I could read the code and learn more about where this element of the system is handled, but haven't found anything yet.

Any clues appreciated

cerbo gxVenus OSVE.Direct
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Justin Cook avatar image Justin Cook ♦♦ commented ·

Moved to Modifications Space for non-supported systems; this is due to the statement that you are using non-supported cables (DIY comms cables are not supported, for obvious reasons). In the Modifications Space you are more likely to encounter other Victron product owners who might have the data you're looking for!

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1 Answer
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Just use the original cables and you should have no problems.

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greg-johnson avatar image greg-johnson commented ·

Thanks Matthias.

I asked for confirmation of the pinout and details about how to use the root access to verify serial connectivity.

I don't have any of your custom overmoulded cables (the connector Victron chose, the JST-PH is not recommended for overmoulding nor 'outside the enclosure') but I'm quite cable of crimping those pins.

Is it not possible to confirm the pin out?

Merry Christmas!

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hyxamp avatar image hyxamp greg-johnson commented ·

Hi. Your described pinout is right. Make sure you have the right RX and TX pinout at the producer and costumer. Producer Pin 2 is RX, Pin 3 is TX (v.3.22). I used to work with an older version of the VE.Device protocol which I found first in the internet (01.04.2016 - v.3.21), where the pinout is switched (Producer RX pin is 3 and TX pin is 2) and it didnt worked. They changed the pinout in version 3.22.

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