Regarding compatibility with F and S series

[pablonajarrofever]

Hi,

In the project's wiki it's mentioned that, though not tested, it probably works also in F and S-series.

However, the pinout for the invertor connector seems to be different, as can be read in the User Manuals of the different series (https://www.fox-ess.com/downloads/#1608629474343-a4d4beb2-71e3; page 16 of F Series User Manual, for instance).

In F and S-series pin 7 is “NC” (not connected), it doesn’t supply the +12V as in T. And pins 1 and 2 are used for CT (the Current Transformer sensor of the AC line); so we cannot access RS485 through these pins.
Pins 3 and 4 are, in all three series, assigned to Meter 485. I wonder if their usage is restricted to the connection of a limiting meter, as explained in the manuals, or they are also available for plain RS485 connection. That would allow me to use this setup, though wiring (and powering of circuits) should be different.

Thanks and regards

[assembly12]

Hi,
yes sadly you are correct. It probably doesn't work with F and S series. At the time I thought the pins labeled with 485- and 485+ would broadcast the serial connection of the inverter. But as it seems, these contacts are meant to be connected to an export limiting meter.
I will remove the suggestion that this might work with F and S series from the wiki.
Thanks for bringing this to my attention and I'm really sorry if I caused you to have false hope!
You might still be able to tap into the RS485 line of the wifi dongle, but thats something I'm not willing to try out for myself at this moment.

[Eng65745]

Hi,

I also have a Photovoltaic installation with a FoxESS F-Series inverter installed recently, and have just found this thread. Could you clarify the point of "tapping into the RS485 line of the wifi dongle" in the previous post? Does the dongle connect to the inverter through a RS485 connection? or does it provide a RS485 line itself ? (how?, where?)

Let me cling to the hope you so kindly mentioned above...

Regards

[assembly12]

Hi, the dongle probably connects to the inverter via RS485. I don't have an F-Series, so I can not say for sure. Even if you are able to connect to this serial, the protocol on this connection must be same. So no guarantee of succes.
One way to go about it, might be the following. If you can get hold of a second wifi dongle (for cheap), you could flash it with esphome. If you're lucky it should work right away. But still no guarantees whatsoever. Only downside is, you can't connect to the Foxess cloud anymore.

[SibrenVasse]

Hi!
I also have a F-series inverter. I have captured the network traffic between the WIFI dongle and the cloud server.
One of the data packets that I captured seemed to match the specification in the header file. (Size 165 and 0x7E7E ... E7E7)
Next I tried decoding some fields that were of interest to me: pv1_voltage_value, pv1_current_value, today_yield_value, total_yield_value. The resulting values all matched those displayed in the app.
So the protocol seems to be at least very similar.

The dongle is connected by 4 pins to the inverter. So probably those would be two data lines, VCC (probably 12V, as the side of the dongle says 7v-12v dc) and ground? This would suggest it would be possible to wire the hardware setup on the wiki to this port.

[SibrenVasse]

Update:
The dongle has 4 connectors. Outside, on the connector they are labeled 1-4.
Inside, on the PCB they are labeled:
1: +
2: -
3: A
4: B

There is a SMD ESP-WROOM-02U inside.

[Eng65745]

Hi,

This is to confirm the assumption by assembly12 that wifi dongle connects to inverter by RS485, as stated in a FoxESS official datasheet, product specifications, last line: "Communications Method: RS485".

smart-wifi datasheet.pdf

Thanks to both assembly12 and SibrenVasse, your posts are very helpful to achieve data collection directly from the inverter instead of FoxESS Cloud that, by the way, seems to experience frequent outages not being accessible for several hours (though it keeps collecting data). Last time, yesterday May 1st.

[assembly12]

ok. That looks very promising!
It looks like this repo will work on the wifi (usb) bus as well. The hardware setup as described in the wiki should work, only the connector has to be swapped to usb.
If anyone is willing to try this out, im happy to assist.

[SibrenVasse]

Just to be clear: the wifi dongle is not connected via the USB port of the device! The USB port is only for mass storage devices for a fimware upgrade of the inverter.

The connector is screwed into the inverter with a connector that looks like this one:
https://m.media-amazon.com/images/I/61-1h5O01KL._AC_UF1000,1000_QL80_FMwebp_.jpg
The dongle is the female side, the inverter has the male connector.

I'm looking into the exact size of this connector and see if I can order one and try it with the hardware described on the wiki.

[Eng65745]

In case it helps: I found these drawings with the exact sizes of the connectors SibrenVasse show (it seems they are commonly used for microphones and in aviation, in a local store they cost between 2 and 3 euros). I attach two versions of the male connector, the one to mount on a chassis and the one to attach to a cable (exactly the same dimensions as the female, it seems).

[Eng65745]

Sorry, dimensions for male and female cable connectors are NOT the same (they shouldn't or they won't fit!)

[Eng65745]

Hello,

I had the chance to measure the Wifi dongle and compare to the audio-type connectors shown by SibrenVasse or myself in previous posts.

The body of the dongle connector is sligthly larger (by 0.2 mm, aprox) than the audio-type connectors. In fact, I tried to plug one audio-type connector into the inverter and it fits, pins match, but the slight difference leaves the connector a bit loose; in vertical position it would slip out. Maybe a couple of turns of tape would make for the difference and the connector would stick.

The real difference is on the fastening nut; the dongle's nut is 22.4 mm in diameter, the audio-type connector's nut 18 mm.

Also, labelling of pins is different - pairs 1 & 2 and 3&4 are reversed.

In summary: one of these conventional audio-type connectors can be plugged into the inverter, pins will match, but it cannot be fastened, so it would require some element to keep it firmly in place.

[SibrenVasse]

I have ordered this connector: https://nl.aliexpress.com/item/1005005256853917.html

Unfortunately, this listing on AliExpress has become much more expensive since I ordered.

This connector fits on the inverter and you can tighten the screw. The only thing is the indentation on the side of the connector is a little bit too small, so disconnecting it from the inverter is a little bit difficult. You can probably widen this indentation by filing it down to make it fit better.

[Eng65745]

Hello SibrenVasse,

I've noticed the reference from aliexpress is a package of 10 pairs of male-female connectors. If after you've completed your project you don't have an use for some of them, I'd be glad to purchase a pair from you and help you to recover costs.

[SibrenVasse]

I'm sorry but there used to be an option to only buy one.
So I only ordered one connector!

[SibrenVasse]

All parts have arrived, so I have completed building the hardware as specified on the wiki. I will report back with my results.