Victron VE.Direct to USB DIY | $4.09 one cable | Do It Yourself 

Hi Chris, Thanks for bringing this up and it looks like I made a mistake with my labeling for the JST 4 Pin connector. The correct labeling is: Pin 1 (black) - GND Pin 2 (red) - RX Pin 3 (white) - TX Pin 4 (yellow) - +5V Still, the color matching is correct, it is just the labeling of the JST 2.0 4 Pin cable off.

@@tobisreallifeskillswithtobi that''s really handy to know once we've expanded every comment to look at replies. Why isn't this error at the top of your description info ? Pointing out that 5V pin4 is on the left of the Victron 75V models would also be useful. It's the other way up , so on the right on 100V.

@@tobisreallifeskillswithtobi sorry im still confused can you do a overlay of the correct pinout plz

@@tobisreallifeskillswithtobi Hi. I just bought some JST connectors. On the picture on Amazon they look the same, but now they have different colors, They have red, black, yellow and green. So which color is what?

Yes indeed, 70 euro (cheapest I can find) for the MK3 ve.bus to usb is a lot

Thanks for sharing your experience with the community! I did indeed not use it that way!

Thank you for your reply. I purchased all the parts and was trying to figure out why the video showed Rx go to Gnd, so I decided to look in the comments and found your reply to the isolation topic. That made me go read the VE.Direct Protocol, and found where it states "...provides galvanic isolation between the VE.Direct product and the host (your computer/PLC/etc)". So I'm not going to make this cable, and have to use some other way to extend the USB cable. That way maintaining the Galvanic Isolation used by Victron's cable. I do thank you Tobi, for making the video however, it and my research has taught me more about the victron systems

@@jbat66 I am curious as to how you extended your usb cable. I have the same problem, my equipment is about 12' from where I want to mount the pi and screen. I have never seen usb extension cables that long and would be concerned about data integrity. Maybe just extend the cable after the isolation? What have you done to solve this?

I got a USB extension cable from amazon, cut it so the wire would go through a small hole, and then soldered it back together.

use the board with ADUM1201 to prevent ground loops

Der MK3-Adapter ist für einen VE.BUS und NICHT für VE.direct !

Yes, there are some downsides for making the cables yourself. I will make a follow up video to clarify this.

I am not aware of that, sorry

Good question, let me check

While not color matching you could use Cat 3 or better Phone or Ethernet wire. they are solid core (low resistance), and twisted to protect the data in transit. AKA UTP (Unshielded Twisted Pair)

Thanks for sharing !

Yeah these cables are not isolated, meaning that the ground from the shunt or smartsolar, will be shared through the usb and whatever it is connected to. In my case, i had a raspberry pi being powered from a buck converter on the output side of my bms, and the bmv712 connected before the bms, and when the bms turned off, it literally blew the buck converter to pieces, as the inverter tried to pull its full power through the usb cable and rpi. The genuine ve direct cable i gather is more expensive because it is completely isolated internally, so this fault wouldn't occur with the genuine cable. I gather you may have had a similar issue. This however isnt an issue if your rpi is powered by an isolated source and you are only using one of these diy cables, as theres no ground loop through the usb cable

@@lexicase8805 Good point. Best solution is to put a simple optocoupler between the USB cable and the JST cable.

Hi @@lexicase8805, i am facing this exact issue i believe and my MPPTs keep dropping out until i reboot my raspberry pi and then they show up again for a few hours and then they disappear again. Could you please clarify what it means to "power the RaspPi from an isolated power source" ? and further more, you stated "only using one of the DIY cables". Does that mean i cannot use 2 or 3 DIY cables even if RaspPI is powered via isolated source? Thanks!

@@waseefarshad509 so basically whats happening is the power in your system with non isolated cables, can flow not only through your main power cables, its able to flow through your data cables as well, which is extremely bad! So the victron gear is sensing this power flow where it shouldnt be, and protecting itself which is why it drops out. An isolated power supply would be something that doesnt have a connected path through either power or ground from the battery side to the usb side. Try powering your raspberry from a portable usb power bank, that would be absolutely isolated. I was also using 3 diy cables and have since replaced them all with genuine victron cables as i didnt have time to wait, but there are apparently isolated versions of the TTL cables, i just dont know what to look for. What that means is that the usb end only sees the data from the victron device, but the power and ground are not directly connected, they are protected by some fancy circuitry i dont understand. I decided to switch to genuine victron cables a few days ago as one of my systems had a raspberry pi powered through a buck converter since it was only a 12v system, and the raspberry pi only running one bmv712. The buck converter was connected after the bms, the bmv shunt before the bms. When the bms did shut down, the ground then flowed from the bmv shunt data cable, through the bmv screen, diy ve direct cable, through the pi and buck converter ground and tried to continue the negative supply that the bms was trying to shut off. The raspberry, bmv712, buck converter and all cables between, caught fire. Over $500 in the bin because i didnt use a genuine $40 ve direct cable.

I was wondering why the original cable from Victron had that little 'box' along the cable.

how would I include something like a BOJACK PC817 Optocoupler in that? Thanks!

@@JulianGoesPro Try the ADUM1201 - its made for this. And NEVER use that cables, without an optocoupler, u can fry your victron units, if u have a gnd loop ore something else. many ppl fried their mppt chargers and so on, because they saved that 2$ piece ^^

Thanks for your comment. I read something like this as well but wasn't bale to verify it. Do you have more information to share about this?

The cable works without connecting the +5v cable indeed.

If PV is connected,+5v wire has no use.

@@tobisreallifeskillswithtobi This should have all the information (in german) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-V0daJC69GWM.html

@@tobisreallifeskillswithtobiI would just avoid connecting the 5V altogether. It can only lead to danger.

What would be your intention when connecting the inverter to a PC? It can be connected to a device which runs VenusOS for example - which can communicate through the cable.

@@tobisreallifeskillswithtobithank you for your reply. I would like to adjust cut off voltage, top voltage and load check period. It's a phoenix 375VA inverter. I'm just worried about connection without optocoupler. Can I have any issues without an optocoupler when connecting to PC with DIY cable?

Well, NO! This is not just a 1:1 wire connection. You need to take into account the USB-to-Serial converter (e.g. FTDI or PLC2303) within the blue USB unit, plus the galvanic isolation that's missing from this DIY sketch but which you may want to have for dealing with ground loops and/or 5V/3V3 differences (see other comments).

Should work. Check voltage levels, I'm not sure Pi GPIO will take 5V signals. RX/TX may need to be crossed over.

Thanks for the video, have you noticed that the cable loses connection randomly meaning you have to unplug the cable to reset it?

Best way to fry directly your Raspberry.

I had a unique case where my batteries are 40 ft away in a shed outside my home. his is also where my smart shunt is. I did this as my batteries are NiFe batteries and off gas hydrogen. I used usb extension adapter via ethernet cable. Then ran an ethernet cable to my shed. I thought something in the length could also be a problem but changed the pinout to match how Andy did it and voila! it worked.

Thanks for sharing! I have to look into this :-)