Inside a Victron MK2 dongle

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My curiousity finally got the better of my yesterday, and since it's just 4 small plastic clips that you can undo with minimal damage (the screwdriver always leaves a small indentation), here it is.

Basically, the guts is a PIC microcontroller. There is a FTDI chip in there to turn it into a USB device. Bottom left is a line protection chip, I assume that protects the ftdi. Nice touch! If you're cheap, you would just wire the usb directly to the ftdi. Interesting as well, top left, two opto-coupler chips, clearly for the serial comms. So the ftdi is powered from the PC side and the microcontroller is powered from the inverter side.

It also explains why such a low baud rate is used. The opto-couplers aren't capable of high speeds. Max baud rate used is 19200, when flashing firmware.

[SilverNodashi]

wonder why didn't build it into the inverter?

[HeinTheTerrible]

2 hours ago, SilverNodashi said:

wonder why didn't build it into the inverter?

To make more money!

[SilverNodashi]

21 minutes ago, HeinTheTerrible said:

To make more money!

well, ya, that was my first thought as well: it would have been a bit cheaper to embed the components onto the main PCB. But is that really the only reason? 

[HeinTheTerrible]

Just now, SilverNodashi said:

well, ya, that was my first thought as well: it would have been a bit cheaper to embed the components onto the main PCB. But is that really the only reason? 

Probably not but most will guess it's about making money.

My guess is that they already have a bulletproof inverter design so incorporating it now would cost more R&D to make sure it works. It might also be that the tech wasn't up to scratch back then so making a separate unit was a better choice for keeping up with times? 

[Guest]

Just now, HeinTheTerrible said:

Probably not but most will guess it's about making money.

My guess is that they already have a bulletproof inverter design so incorporating it now would cost more R&D to make sure it works. It might also be that the tech wasn't up to scratch back then so making a separate unit was a better choice for keeping up with times? 

Or they thought not many people would need this and when people started asking, they said, here you go, after which still very few people needed it.

[HeinTheTerrible]

Just now, The Terrible Triplett said:

Or they thought not many people would need this and when people started asking, they said, here you go, after which still very few people needed it.

I had the same thought after I posted my previous post. This is most likely the case, techie youngsters buying to solar power are stat hungry so Victron delivered!

[Guest]

When I got my inverter I changed the DIP's and there we went. YEARS later I read there is a connector, Mk2, so I got it. Once I had it I did not need it, for I did not need to make any changes.

Couple years later I wanted to read the data ... that day I was glad I bought it. 

[___]

Simple. You need only one Mk2 for the whole bus, which could have several inverters in parallel or three phase, and even some charger products. You can also do without one for very simple ups setups. So it makes complete sense to keep it separate.

Sent from my GT-I9195 using Tapatalk

[cvzyl]

11 hours ago, plonkster said:

Nice touch! If you're cheap, you would just wire the usb directly to the ftdi.

@plonkster, what do you estimate the cost of all the components to be?

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47 minutes ago, cvzyl said:

@plonkster, what do you estimate the cost of all the components to be?

USB6B1 chip, R20

FT232RL, R 75

SFH6156 (times 2), R17

PIC16F73, R70

Not sure about the chip bottom right. Add in all the discrete components on the board and so on, and R250 is a conservative estimate of the main components. Add in PC board, cabling and plastic case, I'd say R400-R500 or so worth of raw material. Ie about half of what it sells for.

Victron's main business is selling inverters. That's where they make their money. The rest of the stuff is of lesser concern and when it comes to cables they pretty much sell at cost or very little markup. Of course our local importers don't necessarily do the same. Eg, ExSolar sold the vedirect-usb for R1050 at some point. A few weeks ago I enquired again and the price was around R500. In Euro terms the price didn't halve though... so the original price obviously included a healthy markup :-)