KC868-A2 SIM7600 with Tuya GPRS not work

[admin]

we are under testing, will release new firmware to fix it.

[alexps70]

Мне нужно, чтобы Tuya работала через Ethernet (он кстати не выключается) и при его недоступности переключалась на GPRS как на резервный канал связи. Такое можно реализовать? Либо управление Tuya работает через GPRS, но остальные протоколы (WEB/MQTT/HTTP и т.п.) работают через LAN

I need Tuya to work through Ethernet (by the way it does not turn off) and with its inaccessibility switched to GPRS as a reserve communication channel. Can this be realized? Or Tuya management operates through GPRS, but the rest of the protocols (Web/Mqtt/Http, etc.) work through LAN
Переведено с Google (Russian → English)

[admin]

you can set tuya use by ethernet or 4G. But only one way, can't auto switch to GPRS when ethernet is disconnected.

[alexps70]

Усли я активирую опцию GPRS - Tuya не работает, даже если полностью отключить кабель Ethernet - как я понимаю, этот баг будет исправлен.
Но я спрашиваю о втором моменте - если активирована опция GPRS для работы Tuya, будет ли работать управление по LAN по другим протоколам?

I activate the GPRS option - Tuya does not work, even if you completely turn off the Ethernet cable - as I understand it, this bug will be fixed.
But I ask about the second moment - if the GPRS option is activated for Tuya, will there be a LAN control for other protocols?
Переведено с Google (Russian → English)

[admin]

yes, you are right, only GRPS with tuya, other protocols work with ethernet.

[alexps70]

Хорошо, жду, когда работа Tuya через GPRS будет исправлена

Okay, I'm waiting for the work of Tuya through GPRS will be fixed
Переведено с Google (Russian → English)

[panarosa]

I have followed the documentation available on your website, but some of the links provided are either unavailable or no longer functional.
I have tested two different SIM7600E modules, and neither shows any sign of operation: they do not respond to AT commands and do not register on the network.
My goal was to integrate the KC868-A2 into a patented project with potential industrial application. I was convinced that your product could simplify my solution, but to date, I have not been able to use it.
I kindly request:

1. An updated step-by-step guide for configuring and testing the KC868-A2 with Arduino IDE.
   
2. Working links for downloading drivers, libraries, and example sketches.
   
3. Any specific instructions for verifying the proper functionality of the SIM7600E module.
   

If we can find a solution, it will be mutually beneficial. Otherwise, I will be forced to abandon the use of this module.
Technical Tests Already Performed on KC868-A2 with SIM7600E

1. Development Environment Setup
   • Arduino IDE (tested with both version 1.x and 2.x)
     
   • Official ESP32 core installed via URL:
     
     
     Code:

     https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
     
     
   • Selected board: ESP32 Dev Module
     
   • Baud rate set to 115200
     
2. Sketch Upload
   • Tested official KinCony sketches for KC868-A2 with SIM7600
     
   • Tested custom sketches for sending AT commands
     
   • Tested with PSRAM disabled to eliminate
     
     Code:

     PSRAM ID read error
     
     
   • Compilation and upload completed successfully → ESP32 is working correctly
     
3. Connections and Power Supply
   • KC868-A2 powered with 12V as per manual
     
   • LTE antenna connected to MAIN port of SIM7600 (not AUX/GNSS)
     
   • Verified presence of power and indicator LEDs:
     • Red power LED solid on
       
     • Green modem LED blinking continuously
       
4. SIM Cards
   • Tested two different SIM cards in two different SIM7600E modules → no response
     
   • SIM cards confirmed working in a mobile phone
     
   • SIM PIN disabled
     
   • Contacts cleaned
     
   • Correct insertion verified
     
5. AT Command Tests from ESP32
   • Code:

     AT
     ,
     
     Code:

     AT+CPIN?
     ,
     
     Code:

     AT+CSQ
     ,
     
     Code:

     AT+CREG?
     → no response
     
   • Serial Monitor shows nothing or “modem not found”
     
6. Alternative Checks
   • Attempted direct connection via USB MODEM to PC (drivers not easily available)
     
   • Tried alternative SIM slots and different LTE antennas
     
   • Evaluated alternative GSM modules (SIM800C, SIM800L) → working in other projects
     

---

Conclusion:
The ESP32 works and communicates correctly via USB, but the SIM7600E module does not respond to any AT command, even after testing with two different units, proper power supply, and a suitable LTE antenna.

[admin]

take a photo , how you connect with 4G module, what power supply you are using?

[alexps70]

we are under testing, will release new firmware to fix it.

When is a decision expected?

[WestfieldGhost]

Hi everyone,

I just wanted to add that I am seeing exactly the same behaviour as alexps70 and apps4check on my KC868-A2 with SIM7600, using the latest KCS V2 firmware.

In my case the KC868-A2 is installed completely outside my home network – it is never connected to LAN or Wi-Fi. The board is in a remote location and has LTE-only connectivity, and my goal is to control it from Home Assistant over LTE, without any extra gateway hardware.

The SIM7600 LTE module itself works perfectly. When I connect the modem directly to a PC over USB and send AT commands, I can see that:

• the SIM is ready
  
• the module registers on the LTE network
  
• the APN is accepted
  
• NETOPEN is successful
  
• the modem receives a valid mobile IP address
  

So the SIM card, the LTE network and the 4G hardware are all working fine.

The problem starts when the SIM7600 is used together with the KC868-A2 and the KCS firmware. As soon as I activate the GPRS / 4G option for Tuya, I see the same thing that was described above:

• GPRS shows “connected”, but
  
• Tuya stays disconnected, even if Ethernet is unplugged
  
• the time is not synchronized (no NTP over mobile data)
  
• there is no sign that LTE data is actually used
  

MQTT behaves in the same way:
It works when the A2 is connected via LAN / Wi-Fi, but as soon as the board relies on LTE only, the MQTT connection does not work anymore. From what I can see in the web UI, the GSM section only supports SMS and Call Test, and there are no APN or PDP settings and no LTE data status indicators available. This matches very well with the logs and descriptions from alexps70.

From all these tests it looks like the SIM7600 does establish a full LTE data session, but the KC868-A2 firmware does not route any Tuya or MQTT traffic over the mobile data interface. In other words: LTE seems to be limited to SMS/Call functions (and maybe Tuya on some boards), but not usable as a general data connection on the A2 right now.

For my use case this is critical, because my KC868-A2 will never be in my home LAN. It needs to work exclusively over LTE, and it needs to be controllable from Home Assistant in that mode.

So my question to the admin is:

• Does the KC868-A2 firmware currently support using the SIM7600 LTE data connection for Tuya and/or MQTT at all?
  
• If yes, which firmware version or configuration is required to make this work, especially in a setup where the device has no LAN/Wi-Fi available and must run LTE-only?
  

If there is a test firmware that fixes the Tuya over GPRS problem mentioned earlier in this thread, I would be happy to test it as well.

Thank you.