Smart Home Automation Forum
Kincony KC868-A16 (ESP32) - I2C PCF8574 entities visible in HA but not responding (I2 - Printable Version

+- Smart Home Automation Forum (https://www.kincony.com/forum)
+-- Forum: Technical Support (https://www.kincony.com/forum/forumdisplay.php?fid=20)
+--- Forum: KC868-A16 (https://www.kincony.com/forum/forumdisplay.php?fid=25)
+--- Thread: Kincony KC868-A16 (ESP32) - I2C PCF8574 entities visible in HA but not responding (I2 (/showthread.php?tid=9133)

Kincony KC868-A16 (ESP32) - I2C PCF8574 entities visible in HA but not responding (I2 - bobbisasha - 03-17-2026

Hi everyone,
I’m struggling with a Kincony KC868-A16 board (ESP32-based) integrated with ESPHome in Home Assistant. I can see all the entities (switches and binary sensors) in my HA dashboard, but none of the physical relays or digital inputs are responding.
The Hardware:
  • Board: Kincony KC868-A16 (V1.5 or similar with 4x PCF8574 IO Expanders).
  • Power: Externally powered with a stable 12V 2A DC supply.
  • Checked with Multimeter: PCF8574 chips are correctly powered at 3.3V.
The Problem: When I toggle a switch in Home Assistant, the UI icon turns "ON" for a split second and then immediately reverts to "OFF". This suggests an I2C communication timeout or write failure. No physical "click" is heard from the relays, and LEDs don't light up.
ESPHome Logs: The I2C scan successfully finds all 4 chips at the expected addresses:
  • Code:
    Found device at address 0x21
     (Inputs)
  • Code:
    Found device at address 0x22
     (Inputs)
  • Code:
    Found device at address 0x24
     (Outputs/Relays)
  • Code:
    Found device at address 0x25
     (Outputs/Relays)
Log output: 
Code:
[C][pcf8574:024]: PCF8574: Is PCF8575: NO, Address: 0x24
 However, when I trigger a relay, nothing happens physically.

here some .yaml config examples for my digital sensors and outputs: 
Code:
remote_receiver:
  pin:
    number: GPIO2
    ignore_strapping_warning: true # Could this be interfering with I2C boot?

remote_transmitter:
  pin:
    number: GPIO15
    ignore_strapping_warning: true
  carrier_duty_percent: 100%

i2c:
  sda: GPIO4
  scl:
    number: GPIO5
    #ignore_strapping_warning: true
  scan: true
  id: bus_a

pcf8574:
  - id: 'pcf8574_hub_out_1' # for output channel 1-8
    address: 0x24
  - id: 'pcf8574_hub_out_2' # for output channel 9-16
    address: 0x25
  - id: 'pcf8574_hub_in_1' # for input channel 1-8
    address: 0x22
  - id: 'pcf8574_hub_in_2' # for input channel 9-16
    address: 0x21

binary_sensor:
  - platform: gpio
    name: 'Digital Input 01'
    id: input1
    pin:
      pcf8574: pcf8574_hub_in_1
      number: 0
      mode: INPUT
      inverted: true
    internal: false

switch:
  - platform: gpio
    name: 'Ouput Relay 01'
    id: sensor_relay_1
    restore_mode: RESTORE_DEFAULT_OFF
    pin:
      pcf8574: pcf8574_hub_out_1
      number: 0
      mode: OUTPUT
      inverted: false
    internal: false


RE: Kincony KC868-A16 (ESP32) - I2C PCF8574 entities visible in HA but not responding (I2 - admin - 03-17-2026

take a photo of your PCB , i want to see how you wire, make sure whether have lost the RED cable in my photo.
   

RE: Kincony KC868-A16 (ESP32) - I2C PCF8574 entities visible in HA but not responding (I2 - bobbisasha - 03-20-2026

(03-17-2026, 11:37 PM)admin Wrote: take a photo of your PCB , i want to see how you wire, make sure whether have lost the RED cable in my photo.

thanks for your time. I connected the cable as you said; now the status LED of Y1 turns on when Y1 is normally closed. 
I am using a 12V 2A power supply. When Y1 closed, the L00 and Y1 voltage keeps to 0 V wrt power supply (correct operation); when opening Y1, the actual voltage is 10.70 V (L00 - Y1) with no load, meaning 0.4 V (Y1-Gnd) of loss. 

My aim is to connect a 12V siren to y1 output. can u pls show me an example of connected output load to one of the Yx outputs.

thanks

RE: Kincony KC868-A16 (ESP32) - I2C PCF8574 entities visible in HA but not responding (I2 - admin - 03-20-2026

you should connect with load to test.