Nous A8M Smart Matter Socket 16A

Product Description

The Nous A8M is a 16A EU smart socket with energy monitoring, a physical button, and an LED status indicator. It is based on the BK7231N chip and ships with Matter support.

Specifications:

• Operating Voltage: 220–240 V AC
• Maximum Load: 16 A (3840 W)
• Standby Power: 1.3 W
• Connectivity: 2.4 GHz Wi-Fi (802.11 b/g/n)
• Dimensions: 45 × 45 × 73 mm
• Protection: IP20

Flashing

Important: Bootloader Mismatch (Matter variant)

Nous A8M plugs with Matter support ship with a Tuya bootloader v3.0.0 instead of v1.0.1. This causes two issues during conversion:

• OTA updates appear to succeed but are never applied — the v3.0 bootloader layout is incompatible with what the v1.0.1-based flow expects, so the partition swap does not occur.
• Devices flashed without accounting for the different layout show an incorrect MAC address (e.g. C8:47:8C:00:00:00) because calibration/userdata TLVs are read from the wrong offsets.

Solution: Flash the bkboot 1.0.1 bootloader before flashing ESPHome firmware:

ltchiptool write <port> bk7231n 0x0 bk7231n-1.0.1-encrypted-tuya.bin --length 0x11000

The board_flash.calibration platformio option in the configuration below is also required to read calibration data from the correct offset.

Flashing Steps

Use ltchiptool to flash the device over UART. You will need to open the device and connect to the UART pads on the BK7231N chip (TX, RX, GND, and briefly bridge CEN to GND to enter flash mode).

1. Flash the bkboot 1.0.1 bootloader as shown above.
2. Flash the ESPHome firmware using ltchiptool or the ESPHome OTA mechanism.

GPIO Pinout

Pin	Function
P6	Relay
P7	Button (inverted)
P8	LED (inverted)
P14	BL0937 SEL (inverted)
P24	BL0937 CF
P26	BL0937 CF1

Basic Configuration

substitutions:
  name: nous-a8m
  friendly_name: Nous A8M
  # Higher value gives lower current readout — calibrate for accuracy
  current_res: "0.00112"
  # Lower value gives lower voltage readout — calibrate for accuracy
  voltage_div: "768"

esphome:
  name: ${name}
  friendly_name: ${friendly_name}
  name_add_mac_suffix: false
  project:
    name: "NOUS.Smart-Wifi-Socket"
    version: "A8M"
  platformio_options:
    board_flash.calibration: "0x1E3000+0x1000"
  on_boot:
    priority: 200
    then:
      - if:
          condition:
            switch.is_on: relay
          then:
            - light.turn_on: led
          else:
            - light.turn_off: led

bk72xx:
  board: generic-bk7231n-qfn32-tuya

logger:

api:

ota:
  - platform: esphome

improv_serial:

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  ap: {}

captive_portal:

time:
  - platform: homeassistant
    id: my_time

light:
  - platform: status_led
    name: "Switch State LED"
    id: led
    internal: true
    pin:
      number: P8
      inverted: true

binary_sensor:
  - platform: gpio
    name: "Button"
    id: push_button
    internal: true
    pin:
      number: P7
      inverted: true
      mode: INPUT_PULLUP
    on_press:
      - switch.toggle: relay

switch:
  - platform: gpio
    pin: P6
    id: relay
    name: "Relay"
    restore_mode: RESTORE_DEFAULT_OFF
    icon: mdi:power
    on_turn_on:
      - light.turn_on: led
    on_turn_off:
      - light.turn_off: led

sensor:
  - platform: hlw8012
    model: BL0937
    current_resistor: ${current_res}
    voltage_divider: ${voltage_div}
    sel_pin:
      number: P14
      inverted: true
    cf_pin:
      number: P24
      inverted: true
    cf1_pin:
      number: P26
      inverted: true
    current:
      name: "Current"
    voltage:
      name: "Voltage"
    power:
      name: "Power"
    energy:
      name: "Energy"
    update_interval: 10s