How does Victron bluetooth work?

[T6Jay]

Is there any victron bluetooth experts on here?

I have fitted an arduino and display in my van and would like to put a EHU CONNECTED warning on the display, in big flashing letters! I can see two ways to do this;

1. Connect a 240V relay in the consumer unit and connect the contacts to arduino inputs;
PROS - simple
CONS - lots of work to wire up, 240V and 12V in close proximity

2. Have the arduino look for the Victron EHU 12/15 charger on bluetooth, no need to even talk to it, just see if it exists.
PROS - arduino already has bluetooth so no wiring. No voltage mixing
CONS - can't think of any

Anyone have any insights into all this?

Taking things a step further, and maybe better in future threads;
Can I get get some charging info from the 12/15 bluetooth on my display?
How could I let the arduino know there's a bum in the drivers seat, and only warn about the EHU if so?
How could I safely prevent the van from starting if the EHU is plugged in?

Here's the display;

 

[RayF]

Have you downloaded the Victron Connect app? You view and control the components through this app

 

[RayF]

Also, any monitoring of Victron equipment not done through the app needs an external device connected using the Victron VE direct cables to a Victron GX device such as GX Colour display. I’m not aware of VE direct working with any non Victron device but I could be wrong. There is a good resource of info on the community section of the Victron website

 

[T6Jay]

Yes I have the app thanks Ray. But in the first instance I want to get an arduino to 'look' if a victron device exists (in bluetooth terms)

Then if possible, I want the arduino to 'grab' some data from the bluetooth victron device.

I'm aware of VE direct, and I think anyone with a bit of serial comms knowledge can hook up to that (victron share the protocols), but the Victron 12/15 does not have VE direct, only bluetooth (and they don't share these protocols)

 

[RayF]

See if you can get any help from here All Posts - Victron Community The guy to talk to at victron is Joannes Boonstra. What he doesn’t know isn’t worth knowing.

 

[andys]

I know you want to use Bluetooth for it, but what about just using a relay on the output from the ehu charger to ground a data pin on the arduin, with a diode to stop back feed?

 

[andys]

Also, any monitoring of Victron equipment not done through the app needs an external device connected using the Victron VE direct cables to a Victron GX device such as GX Colour display. I’m not aware of VE direct working with any non Victron device but I could be wrong. There is a good resource of info on the community section of the Victron website

Yes VE direct is very easy to use with non Victron devices. The GX is very limiting and although they make the software available to run on SBCs like the Pi, it’s no better than the GX. Fair play to them though, they made it a very open protocol and publish how to read all the parameters. Here’s my effort using an arduino to read the output from the VE port on a 100/20 MPPT.

 

[T6Jay]

I know you want to use Bluetooth for it, but what about just using a relay on the output from the ehu charger to ground a data pin on the arduin, with a diode to stop back feed?

The output from the EHU charger has 12V (from the battery) even when the EHU is not connected. If you mean to use a diode to prevent the battery alone from energising the relay, the diode would compromise the charging somewhat (by dropping the charge voltage by 0.6V).

Or maybe I understand you wrong?

In any case, I'm almost sure the arduino bluetooth can at least check the presence of the victron 12/15, if not read it's data.

 

[andys]

The output from the EHU charger has 12V (from the battery) even when the EHU is not connected. If you mean to use a diode to prevent the battery alone from energising the relay, the diode would compromise the charging somewhat (by dropping the charge voltage by 0.6V).

Or maybe I understand you wrong?

In any case, I'm almost sure the arduino bluetooth can at least check the presence of the victron 12/15, if not read it's data.

You are reading me right. You could use a diode with a slightly lower voltage drop though, and you could compensate the voltage coming out of the charger in the settings. Just meant as a fallback if you couldnt get the BT communication to work.

 

[T6Jay]

See if you can get any help from here All Posts - Victron Community The guy to talk to at victron is Joannes Boonstra. What he doesn’t know isn’t worth knowing.

Thanks RayF. Anywhere this subject is mentioned on the web, the victron line is always 'we keep our bluetooth protocol secret'.

Someone seems to have 'hacked' into it here;

GitHub - Olen/VictronConnect: Decompiling the VictronConnect app

Decompiling the VictronConnect app. Contribute to Olen/VictronConnect development by creating an account on GitHub.

github.com

This may be a starting point for me

 

[andys]

I'm having an issue with Victron Bluetooth now. Following the fitting of Valence lithium setup I've quickly rewritten the sketch for the display further up to display battery temperature. It needs rearranging to put it at the bottom but that's a PITA as all they're all at at absolute coordinates so I just want to get it working for now



As you'll notice though, it's not displaying a value even though I'm reading "T" which is the label used for temperature. The arduino is linked physically to the serial port on the MPPT which is linked by bluetooth to the devices below





The MPPT says it's receiving Battery Temperature via the bluetooth network but it's not passing it on through the serial port. Any ideas how I can get it to cooperate?

 

[RayF]

@andys I have battery temp sensing on my victron boat system. I have a temp sensor lead connected to the battery terminal and that goes into the shunt for the BMV 712. I’m wondering if you have the same sensor lead? You have a different system obviously. My smart MPPT displays the temp but it takes the info from being networked by VE direct to a GX display so I’m trying to understand how your system would get it’s temp info from the battery

 

[andys]

@andys I have battery temp sensing on my victron boat system. I have a temp sensor lead connected to the battery terminal and that goes into the shunt for the BMV 712. I’m wondering if you have the same sensor lead? You have a different system obviously. My smart MPPT displays the temp but it takes the info from being networked by VE direct to a GX display so I’m trying to understand how your system would get it’s temp info from the battery

Yes my MPPT displays the battery temperature, which it's getting from the Smart Sense (a stick on temperature sensor) in the list above, it just isn't outputting it through the VE Direct serial port. If you look at the arduino display above, all the figures are being read through that serial port. It's effectively a DIY, more flexible (and much cheaper) version of Victron's own display

 

[andys]

Here's the full spec for Victron's protocol if anyone is interested

 

[RayF]

Yes my MPPT displays the battery temperature, which it's getting from the Smart Sense (a stick on temperature sensor) in the list above, it just isn't outputting it through the VE Direct serial port. If you look at the arduino display above, all the figures are being read through that serial port. It's effectively a DIY, more flexible (and much cheaper) version of Victron's own display

Where is your display panel getting the rest of the info from, is that coming from the MPPT via network cable?

 

[andys]

Where is your display panel getting the rest of the info from, is that coming from the MPPT via network cable?

Yes

 

[RayF]

Yes

The only thing I can think of is the temp isn’t intended to be passed through the VE direct port because it’s displayed on the Victron connect app, or some sort of compatibility issue. I know a couple of good contacts for tech support if you’d like them

 

[andys]

The only thing I can think of is the temp isn’t intended to be passed through the VE direct port because it’s displayed on the Victron connect app, or some sort of compatibility issue. I know a couple of good contacts for tech support if you’d like them

Thanks, it's more tinkerers/programmers I need ideas from really rather than Victron. Temperature is one of the parameters available through the serial port (see the Victron protocol details above), I just need to find what I'm doing wrong in my program.

 

[RayF]

Thanks, it's more tinkerers/programmers I need ideas from really rather than Victron. Temperature is one of the parameters available through the serial port (see the Victron protocol details above), I just need to find what I'm doing wrong in my program.

Are you saying you’re programming the arduino display yourself?

 

[andys]

Are you saying you’re programming the arduino display yourself?

Yes I programmed it about a year ago and it works fine, I'm just trying to add an extra line to it to display battery temperature now I've replaced the AGM with Lithium.