Connection attempts on JK-BMS HW: V19 with SW19.07 fail

[ogoettin]

Hey guys,

is anybody of you aware of any details to the changes on JK-BMS hard- and software from V15 to V19? My initial setup with HW V15H is working just like a charm since months now with exactly this code here (except for a BT-reconnect from time to time for whatever reason)!
But exactly the same ESP32 hardware will NOT connect to a brand new JK-BMS V19A hardware (w/ SW V19.07) in my second setup?! BT connection seems to get initially established somehow (at least in the Android app the JK-BMS device disappears after a connection attempt for ~30s), but Arduino device (==ESP32) just complains after initial connection attempt : Failed to connect to <MAC_ADDR> (btw, MAC address is correct in code :)!
Even worse, after initial attempt it never (re-)tries the MAC address again (but may be this is due to JK-BMS not answering any requests at this stage too - as I said, Android app doesn't find the device either)

Any ideas what's going on there and how to debug this in detail? Many thanks upfront ...

[peff74]

I'm glad that everything is running smoothly for you.
Reconnecting from time to time is normal... it's because of JK itself^^.

It's also interesting to know that my script runs smoothly with V15.
But from V19 onwards, something seems to have changed in the connection setup.

I took a quick look at syssi, which confirms my suspicion that there have been adjustments.
Now we need to see how he solved it.
But I don't have V19 to test it.

[Giddy-Up224]

But I don't have V19 to test it.

@peff74 I'd be happy to extend $40 towards buying one if you let me know where/how to get the $40 to you.

[peff74]

@Giddy-Up224
Thank you for your offer, I feel very honored.
However, I forgot to mention the second problem: I would also need some time^^.

@ALL
Which models now include the V19? Do you have an overview?

[ogoettin]

I can't really comment on the others (40, 100 & 150A) versions unfortunately, but the 200A version I got is now HW V19A (SWV19.07). To be more precise, it is the >> JK_PB2A16S20P <<, bought in bundle with the 4.3" display about two months ago in China ...
According to a firmware collection on Google Drive ( https://drive.google.com/drive/folders/1i0gqmxzb4OBCts5G0TuFlGNGpP2g12es ) there are also firmware images in V19 for the 100A & 150A versions. To me this looks like Jikong goes over to the new hardware versions with all their "Inverter BMS" (as they call it)?!

[Giddy-Up224]

I would also need some time^^.

😂 Yeah, I get that! I think we're all feeling that crunch; at least I am. I just wish I had your experience and knowledge to get these things working. I'm learning slowly but surely. (hopefully)

Thanks again for your work and getting back so quickly on these questions.

[TeguhTeknisi]

JFI, i just flash an esp32 C3 SuperMini for my friend, he using HW: 18A SW: 18.00 and its works

If i find a friend that have V19, i will try and report it.

[TeguhTeknisi]

omg, i forgot that i have JK BD4A20S4P with HW: 19H and SW: 19.07

and its works, i have posted in here #5

Edit: i have use ESP32 Dev and ESP32 C3 SuperMini, all works with the Arduino-jk-bms

[peff74]

Very interesting.
Which version of the Arduino IDE / ESP Core / NimBLEDevice Lib. are you using?
Perhaps that's where the problem lies.

[TeguhTeknisi]

Very interesting. Which version of the Arduino IDE / ESP Core / NimBLEDevice Lib. are you using? Perhaps that's where the problem lies.

from my experience , its all about the esp32 device , some times the bluetooth on the esp32 cannot talk to the JK BMS.
with the same code and the same arduino ide, lib, and etc will solve just by change the esp32.

before it, i have using esphome-jk with mqtt, and i have face the same problem, the bluetooth on the esp32 it the problem, just change it, and it will solve.
and now i use this code because i can use it with cusomized display and blynk legacy.

btw, i have try using arduino ide 1.8.18 with old esp32 core to support esp32 C3, there is alot of talk that esp32 C3 more stable using old esp32 core.
and i have using 1.8.19 with the newest esp32 core, for the NimBLE i use the latest that available on Library manager.

[peff74]

So you think it could be due to the ESP32 hardware?

#Offtopic
Also interesting.
I haven't noticed that the ESP32c3 is better supported with the old core.
I use it for other projects and have no problems with the latest core.
#Offtopic

[TeguhTeknisi]

So you think it could be due to the ESP32 hardware?

#Offtopic Also interesting. I haven't noticed that the ESP32c3 is better supported with the old core. I use it for other projects and have no problems with the latest core. #Offtopic

that what i found out when i make this JK BMS to ESP32, its because the hardware.
sometimes, some android phone cannot talk to JK BMS too, its about the bluetooth hardware.
this what i found out on EV Community and Offgrid with PV community, that have share the problem.

#Offtopic,
i found out this bluetooth problem with the esp32 c3 on esphome forum and some on arduino forum, but nope, its just the same, i dont find any problem with the latest core too.
edit: what i found out is, when you want to make esp rainmaker, it only works on old core.