Smart Home Automation Forum - KC868-A2

KC868-A2v3

Tue, 31 Mar 2026 18:27:45 +0800

Hi,
I would like to design a custom enclosure for the KC868-A2v3 board.
Could you please let me know if you can provide the mechanical drawings (dimensions) and 3D files (STEP/STP) for this board?
Thank you.

Problema a cargar .bin al KC868-A2

Wed, 07 Jan 2026 07:26:09 +0800

Hola Amigo, Tengo problemas, no puedo cargar el .bin al KC868 A2, me sale este error al subir:

Running stub...
[2026-01-06 09:06:10,460][ESP8266Loader_spi[1]][espDownloader.py][line:586][ERROR]: ESP32S3 Chip stub error esp_stub_and_set_baud.
no log file output ...

quedo en espera de la ayuda

LAN8720 DHCP implementaion with mqtt arduino source code

Sun, 04 Jan 2026 22:05:12 +0800

Hi.

I bought KC868-A2 board.

I am tryning to send mqtt message to the mqtt broker through LAN8720 with dhcp configuration.

Any example arduino code on this.

Many Thanks for this wonderfull board. Nice Work!!!

KC868-A2 + SIM7600 LTE + Home Assistant – Relays & Sensors over LTE?

Thu, 27 Nov 2025 15:15:40 +0800

Hi everyone,

I’m working on a setup with a Kincony KC868-A2 and a SIM7600 LTE module and I want to connect it to Home Assistant over LTE only.
At the moment I’m using Tuya Cloud, because it seems to be the only solution that officially supports LTE with this board.
My goal is to:

• Control the relays from Home Assistant
• Read inputs and sensor values (ADC, 1-Wire, etc.) remotely via LTE

Current situation:

The device works fine in the Smart Life / Tuya app over LTE
It also appears in my Tuya Developer account
But in Home Assistant it shows as unsupported and I currently have no control at all

So my question is:
Is this device limited when used via Tuya Cloud, or has anyone managed to get full relay + sensor integration over LTE with it?
I’m not fixed on Tuya – it’s just the only LTE-supported method I’ve found so far.

If there is a better approach, I’m open to alternatives.

Has anyone here done this using:
• MQTT over LTE
• Or flashing the ESP32 with ESPHome or other custom firmware (without the original Kincony firmware)?

Important:
? I want to avoid any additional hardware or gateways.

Just the KC868-A2 + SIM7600 + LTE + Home Assistant.

Any ideas or real-world experience would really help.

Thanks in advance!

Using KC868 A2 with Home Assistant / MQTT

Thu, 13 Nov 2025 02:52:03 +0800

Hi,
I didn't found any manual for this board, but the A8 has one here in the forum.

https://www.kincony.com/forum/showthread.php?tid=7164

I have adapted it for using it with the A2 board. So if anyone searches this info, just follow the steps in the A8 posting, but instead add the following to your /homeassistand/configuration.yaml file.

Code:
  switch:

   - name: 'a2-kcs-output-1'

     unique_id: a2-kcs-output-1

     state_topic: 'KC868_A2/99999648C3D98/STATE'

     command_topic: 'KC868_A2/99999648C3D98/SET'

     payload_on:  '{"output1":{"value":true}}'

     payload_off:  '{"output1":{"value":false}}'

     value_template: '{{ value_json.output1.value }}'

     state_on: true

     state_off: false

   - name: 'a2-kcs-output-2'

     unique_id: a2-kcs-output-2

     state_topic: 'KC868_A2/99999648C3D98/STATE'

     command_topic: 'KC868_A2/99999648C3D98/SET'

     payload_on:  '{"output2":{"value":true}}'

     payload_off:  '{"output2":{"value":false}}'

     value_template: '{{ value_json.output2.value }}'

     state_on: true

     state_off: false

Just replace the ID 99999648C3D98 with your board serial number, shown under "Index" in the WebGUI of the KCS software.

I just added the relay-switches, I don't know if there are any more possibilities linke binary sensors or anything. If yes, I think the code from the A8 can be easily adapted.

It worked fine for me.

Regards

KC868-A2 with SIM7600E – Unable to operate after multiple attempts

Sat, 09 Aug 2025 23:00:36 +0800

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
Sketch Upload
- Tested official KinCony sketches for KC868-A2 with SIM7600
- Tested custom sketches for sending AT commands
- Tested with PSRAM disabled to eliminate
- Compilation and upload completed successfully → ESP32 is working correctly
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
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
AT Command Tests from ESP32

→ no response
Serial Monitor shows nothing or “modem not found”
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.

LAN connection lost sometimes

Thu, 07 Aug 2025 04:18:01 +0800

Hello. Board KC868-A2 (revision 2.4) disconnect from the network every couple of months. It seems that the LAN chip freezes, since the link on the router disappears. I found your video with a presentation of the new version of the board, where you say that in the new revision you changed the chip to W5500 https://youtu.be/oFZbByLGK2M?t=293 and that the old chip is unstable. KC868-A2 is located at a fairly large distance to use wifi. Watchdog, if present, does not work and the board can be disconnected from the network many hours until it is rebooted by power manually. What can be done to prevent the problem?

i2c lcd_pcf8574 not working

Fri, 18 Jul 2025 04:33:50 +0800

i got this issue

[22:24:38][C][lcd_pcf8574:024]: PCF8574 LCD Display:
[22:24:38][C][lcd_pcf8574:024]: Columns: 20, Rows: 4
[22:24:38][C][lcd_pcf8574:028]: Address: 0x27
[22:24:38][C][lcd_pcf8574:029]: Update Interval: 0.5s
[22:24:38][E][lcd_pcf8574:031]: Communication failed
[22:24:38][E][component:088]: Component display is marked FAILED:

this my config

esp32:
board: esp32dev
framework:
type: esp-idf

...............

i2c:
sda: GPIO4
scl: GPIO16
id: i2c0
scan: true
#frequency: 100kHz
display:
- platform: lcd_pcf8574
dimensions: 20x4
i2c_id: i2c0
address: 0x27
update_interval: 500ms
lambda: |-
it.strftime(0,0, " %d-%m-%Y %H:%M", id(sntp_time).now());
it.printf(0,1, "T Est %.1f-T Int %.1f", id(tt_ext).state, id(tt_int).state);
it.printf(0,2, "GIARD %s SCALE %s", id(giardino).state ? "ON" : "OFF" , id(scale).state ? "ON" : "OFF");
it.printf(0,3, "GIARD %.0f SCALE %.0f", id(giardino_work_time).state, id(scale_work_time).state);

--------------

what's wrong?
I already changed more displays , try invert sda/scl, try 3.3v and 5v also...

KC868-A2 SIM7600 with Tuya GPRS not work

Mon, 07 Jul 2025 14:56:53 +0800

Hi.
If I activate
connect by gprs (for board have gprs)
will stop working
Please help

Code:
I (83387) web socket: Handshake done, the new connection was opened

I (85490) main: [APP] Free memory: 93520 bytes

I (88665) SIM7600: gprs tuya online

I (90490) main: [APP] Free memory: 93520 bytes

E (93671) SIM7600: ==> ./components/gprs/sim7600.c 865

+CMQTTTOPIC: 0,14

ERROR

I (95490) main: [APP] Free memory: 93520 bytes

E (98677) SIM7600: ==> ./components/gprs/sim7600.c 865

+CMQTTTOPIC: 0,14

ERROR

I (100490) main: [APP] Free memory: 93520 bytes

E (103683) SIM7600: ==> ./components/gprs/sim7600.c 865

+CMQTTTOPIC: 0,14

ERROR

I (105490) main: [APP] Free memory: 93520 bytes

E (108689) SIM7600: ==> ./components/gprs/sim7600.c 865

+CMQTTTOPIC: 0,14

ERROR

If I connect LAN and disable " connect by gprs" - its work

Code:
Boot log with connect by gprs (for board have gprs) deactivated and Lan connected

I (786) cpu_start: Application information:

I (791) cpu_start: Project name:     kc868-a-serial

I (796) cpu_start: App version:      v2.2.11-dirty

I (802) cpu_start: Compile time:     Feb  6 2025 21:47:45

I (808) cpu_start: ELF file SHA256:  810cb7cb959696dd...

I (814) cpu_start: ESP-IDF:          v4.4.7-dirty

I (819) cpu_start: Min chip rev:     v0.0

I (824) cpu_start: Max chip rev:     v3.99

I (829) cpu_start: Chip rev:         v3.1

I (834) heap_init: Initializing. RAM available for dynamic allocation:

I (841) heap_init: At 3FFAE6E0 len 00001920 (6 KiB): DRAM

I (847) heap_init: At 3FFC72C8 len 00018D38 (99 KiB): DRAM

I (853) heap_init: At 3FFE0440 len 00003AE0 (14 KiB): D/IRAM

I (859) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM

I (866) heap_init: At 4008F6B4 len 0001094C (66 KiB): IRAM

I (873) spi_flash: detected chip: generic

I (876) spi_flash: flash io: dio

I (881) cpu_start: Starting scheduler on PRO CPU.

I (0) cpu_start: Starting scheduler on APP CPU.

I (896) main: [APP] Startup..

I (899) main: [APP] Free memory: 215304 bytes

I (904) main: [APP] IDF version: v4.4.7-dirty

I (1178) NVS: init nvs finish.

I (1181) system_api: Base MAC address is not set

I (1181) system_api: read default base MAC address from EFUSE

I (1203) esp_eth.netif.netif_glue: f4:65:0b:e4:14:13

I (1203) esp_eth.netif.netif_glue: ethernet attached to netif

I (2704) eth: Ethernet Started

I (2705) eth: Ethernet init

I (2705) wifi station: ESP_WIFI_INIT

I (2706) eth: Ethernet Link Up

I (2709) eth: Ethernet HW Addr f4:65:0b:e4:14:13

I (2716) wifi:wifi driver task: 3ffd44d4, prio:23, stack:6656, core=0

I (2729) wifi:wifi firmware version: 1fd20f4

I (2730) wifi:wifi certification version: v7.0

I (2730) wifi:config NVS flash: enabled

I (2732) wifi:config nano formating: disabled

I (2736) wifi:Init data frame dynamic rx buffer num: 32

I (2741) wifi:Init static rx mgmt buffer num: 5

I (2745) wifi:Init management short buffer num: 32

I (2750) wifi:Init dynamic tx buffer num: 32

I (2754) wifi:Init static rx buffer size: 1600

I (2758) wifi:Init static rx buffer num: 10

I (2762) wifi:Init dynamic rx buffer num: 32

I (2767) wifi_init: rx ba win: 6

I (2770) wifi_init: tcpip mbox: 32

I (2774) wifi_init: udp mbox: 6

I (2777) wifi_init: tcp mbox: 6

I (2781) wifi_init: tcp tx win: 5744

I (2786) wifi_init: tcp rx win: 5744

I (2790) wifi_init: tcp mss: 1440

I (2799) phy_init: phy_version 4791,2c4672b,Dec 20 2023,16:06:06

I (2885) wifi:mode : softAP (f4:65:0b:e4:14:11)

I (2886) wifi:Total power save buffer number: 16

I (2887) wifi:Init max length of beacon: 752/752

I (2888) wifi:Init max length of beacon: 752/752

I (2893) web_server: Starting HTTP Server on port: '80'

I (2900) gpio: GPIO[0]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 1| Intr:0

I (2907) tuya: start tuya task.

I (2907) ntp: tz:UTC+0

I (2914) tuya: property topic tylink/269d6520ff81b6a74ebev3/thing/property/report .

I (2925) tuya: Other event id:7

I (2925) UDP SERVER: Socket created

E (2927) esp-tls: couldn't get hostname for :m1.tuyaeu.com: getaddrinfo() returns 202, addrinfo=0x0

I (2931) UDP SERVER: Socket bound, port 4001

E (2940) esp-tls: Failed to open new connection

E (2950) TRANSPORT_BASE: Failed to open a new connection

E (2956) MQTT_CLIENT: Error transport connect

I (2961) tuya: MQTT_EVENT_ERROR

E (2965) tuya: Last error reported from esp-tls: 0x8001

I (2971) tuya: Last errno string (Success)

I (2975) tuya: MQTT_EVENT_DISCONNECTED

E (2940) uart: uart_set_pin(689): tx_io_num error

I (2986) uart: queue free spaces: 20

I (2990) gprs: gprs init success.

I (2994) gpio: GPIO[36]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0

I (3003) gpio: GPIO[39]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0

I (3012) gpio: GPIO[2]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0

I (3022) gpio: GPIO[15]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0

I (3031) direct_io: direct io init.

I (3032) MQTT_CLIENT: Publishing skipped: client is not connected

I (3043) MQTT_CLIENT: Publishing skipped: client is not connected

I (3044) gpio: GPIO[33]| InputEn: 1| OutputEn: 1| OpenDrain: 1| Pullup: 0| Pulldown: 0| Intr:0

I (3058) gpio: GPIO[14]| InputEn: 1| OutputEn: 1| OpenDrain: 1| Pullup: 0| Pulldown: 0| Intr:0

I (3067) main: [APP] Free memory: 83620 bytes

I (3706) esp_netif_handlers: eth ip: 192.168.2.138, mask: 255.255.255.0, gw: 192.168.2.202

I (3707) eth: Ethernet Got IP Address

I (3709) eth: ~~~~~~~~~~~

I (3713) eth: ETHIP:192.168.2.138

I (3716) eth: ETHMASK:255.255.255.0

I (3721) eth: ETHGW:192.168.2.202

I (3724) eth: ~~~~~~~~~~~

I (3907) ifttt: start ifttt task

I (5987) wifi:new:<1,1>, old:<1,1>, ap:<1,1>, sta:<255,255>, prof:1

I (5988) wifi:station: a8:96:09:42:ae:ec join, AID=1, bgn, 40U

I (5991) wifi station: station a8:96:09:42:ae:ec join, AID=1

I (6072) esp_netif_lwip: DHCP server assigned IP to a station, IP is: 192.168.4.2

I (8072) main: [APP] Free memory: 86204 bytes

I (9337) wifi:idx:2 (ifx:1, a8:96:09:42:ae:ec), tid:0, ssn:64, winSize:64I (9338) web_server: close() fd (52) success.

I (12617) gprs: uart rx break

I (12980) tuya: Other event id:7

I (13072) main: [APP] Free memory: 84552 bytes

I (14365) tuya: MQTT_EVENT_CONNECTED

I (14368) tuya: subscribe tylink/269d6520ff81b6a74ebev3/thing/property/report_response .

I (14371) tuya: subscribe tylink/269d6520ff81b6a74ebev3/thing/property/set .

I (14377) tuya: subscribe tylink/269d6520ff81b6a74ebev3/thing/event/trigger_response .

I (14385) tuya: subscribe tylink/269d6520ff81b6a74ebev3/thing/action/execute .

ESP32: ETH + RELAY

Thu, 03 Jul 2025 14:47:53 +0800

Hi, I plugged my board via ethernet to my router, but it has no IP, my net is 192.168.2.*.

Anyway, I would like to flash my own code witn ESP32 python to enable / disable relays via http, how to set up a static ip? and which are the gpio pins to enable / disable relays?

Thank you

PCB dimensions & STP model

Tue, 24 Jun 2025 02:26:53 +0800

Hello,
i would like to create a custom case for the KC868-A2 board and i would like to know if kincony can provide the mechanical drawings of the board and STP files

KC868-A2 watchdog

Sun, 22 Jun 2025 01:11:56 +0800

Hello. Does KC868-A2 (with "KCS" firmware) have a hardware or software watchdog?

Protective diodes for relays

Tue, 20 May 2025 17:52:53 +0800

Hello. In the KC868-A2 circuit, the protective diodes D9, D11 are connected in parallel to the transistors, not the relay coils. Is this an error or a feature of the circuit?

out.jpg (Size: 130.19 KB / Downloads: 370)

aduino and kc86822a to D1

Sun, 02 Feb 2025 00:35:02 +0800

BUEN DÍA

PUEDES CONECTAR UN ARDUINO A D1 Y HACER COMUNICACIÓN SERIAL Y TENDRÁS UN EJEMPLO, TANQUES

IP CAM

Tue, 28 Jan 2025 00:54:19 +0800

Good morning,
I would like to know if it is possible to connect an IP camera to the Ethernet port of this card, so that it sends the periodic web shots through the SIM7600 module.