NOUS B3T

This device comes pre-installed with Tasmota. To flash it with ESPHome, refer to the Migrating from Tasmotaguide. Alternatively, you can disassemble the device and solder wires to the test pads (see pinout) for manual flashing.

GPIO Pinout

Pin	Function
GPIO00	LED
GPIO01	TX
GPIO03	BL0939 RX
GPIO04	Button
GPIO05	Switch
GPIO12	Relay
GPIO13	Relay
GPIO18	Switch

Basic configuration

esphome:
  name: nous-b3t
  friendly_name: NOUS B3T
  comment: "NOUS B3T WiFi Switch/Curtain (2 channel with power monitoring)"
  project:
    name: "Nous.B3T"
    version: "2025.6.0"

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

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:
  - platform: esphome

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "NOUS B3T Fallback Hotspot"

captive_portal:

uart:
  tx_pin: GPIO01
  rx_pin: GPIO03
  baud_rate: 4800
  parity: NONE
  stop_bits: 2

sensor:
  - platform: bl0939
    voltage:
      name: "RMS Voltage"
    current_1:
      name: "Current 1"
    current_2:
      name: "Current 2"
    active_power_1:
      name: "Active Power 1"
    active_power_2:
      name: "Active Power 2"
    energy_1:
      name: "Energy 1"
    energy_2:
      name: "Energy 2"
    energy_total:
      name: "Energy Total"

light:
  - platform: status_led
    name: "Status LED"
    id: default_status_led
    pin:
      number: GPIO0
      inverted: true
      ignore_strapping_warning: true
    entity_category: config

switch:
  - platform: gpio
    name: "Switch 1"
    pin:
      number: GPIO12
      ignore_strapping_warning: true
    id: relay_1
    device_class: switch
    restore_mode: restore_default_on

  - platform: gpio
    name: "Switch 2"
    pin: GPIO13
    id: relay_2
    device_class: switch
    restore_mode: restore_default_on

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO4
      mode:
        input: true
        pullup: true
      inverted: true
    id: button
    internal: true
    filters:
      - invert:
      - delayed_off: 50ms
    on_press:
      - switch.toggle: relay_1
      - switch.toggle: relay_2

  - platform: gpio
    name: "Switch 1 (external)"
    pin:
      number: GPIO05
      mode: INPUT_PULLUP
      inverted: true
      ignore_strapping_warning: true
    id: switch_1
    icon: "mdi:light-switch"
    entity_category: diagnostic
    filters:
      - delayed_on_off: 50ms
    on_press:
      then:
        - switch.toggle: relay_1

  - platform: gpio
    name: "Switch 2 (external)"
    pin:
      number: GPIO18
      mode: INPUT_PULLUP
      inverted: true
    id: switch_2
    icon: "mdi:light-switch"
    entity_category: diagnostic
    filters:
      - delayed_on_off: 50ms
    on_press:
      then:
        - switch.toggle: relay_2

Configuration as light switch

This example demonstrates how to configure the 2-gang relay for use with a double rocker light switch. The relay can operate in two modes: directly toggling the connected relays, or in decoupled mode, where switch events are exposed in an event entity that can be used in automations. The NOUS B3T can also be used to control blinds. Refer to the Cover Component and Current Based Cover documentation for further instructions.

switch:
  - platform: template
    name: "Decoupled Mode"
    id: decoupled_mode
    restore_mode: RESTORE_DEFAULT_ON
    optimistic: true
    entity_category: config
    icon: "mdi:connection"

event:
  - platform: template
    device_class: button
    name: None
    icon: "mdi:light-switch"
    id: switch_event
    event_types:
      - switch_1
      - switch_2
      - failsafe

binary_sensor:
  - platform: gpio
    name: "Switch 1 (external)"
    pin:
      number: GPIO05
      mode: INPUT_PULLUP
      inverted: true
      ignore_strapping_warning: true
    id: switch_1
    icon: "mdi:light-switch"
    entity_category: diagnostic
    filters:
      - delayed_on_off: 50ms

    on_multi_click:
      - timing:
          - OFF for at least 50ms
        then:
          - if:
              condition:
                - not:
                    - api.connected
                    - switch.is_on: decoupled_mode
              then:
                - switch.toggle: relay_1
              else:
                - if:
                    condition:
                      - switch.is_off: relay_1
                    then:
                      - switch.turn_on: relay_1
                    else:
                      - event.trigger:
                          id: switch_event
                          event_type: switch_1

      - timing:
          - ON for at least 50ms
        then:
          - if:
              condition:
                - not:
                    - api.connected
                    - switch.is_on: decoupled_mode
              then:
                - switch.toggle: relay_1
              else:
                - if:
                    condition:
                      - switch.is_off: relay_1
                    then:
                      - switch.turn_on: relay_1
                    else:
                      - event.trigger:
                          id: switch_event
                          event_type: switch_1

      # failsafe sequence to turn on/off decoupled mode when HA automation is not working
      # rocker on/off/on of off/on/off
      - timing:
          - ON for 50ms to 350ms
          - OFF for 50ms to 350ms
          - ON for at least 200ms
        then:
          - switch.toggle: decoupled_mode
          - event.trigger:
              id: switch_event
              event_type: failsafe

      - timing:
          - OFF for 50ms to 350ms
          - ON for 50ms to 350ms
          - OFF for at least 200ms
        then:
          - switch.toggle: decoupled_mode
          - event.trigger:
              id: switch_event
              event_type: failsafe

  - platform: gpio
    name: "Switch 2 (external)"
    pin:
      number: GPIO18
      mode: INPUT_PULLUP
      inverted: true
    id: switch_2
    icon: "mdi:light-switch"
    entity_category: diagnostic
    filters:
      - delayed_on_off: 50ms

    on_multi_click:
      - timing:
          - OFF for at least 50ms
        then:
          - if:
              condition:
                - not:
                    - api.connected
                    - switch.is_on: decoupled_mode
              then:
                - switch.toggle: relay_2
              else:
                - if:
                    condition:
                      - switch.is_off: relay_2
                    then:
                      - switch.turn_on: relay_2
                    else:
                      - event.trigger:
                          id: switch_event
                          event_type: switch_2

      - timing:
          - ON for at least 50ms
        then:
          - if:
              condition:
                - not:
                    - api.connected
                    - switch.is_on: decoupled_mode
              then:
                - switch.toggle: relay_2
              else:
                - if:
                    condition:
                      - switch.is_off: relay_2
                    then:
                      - switch.turn_on: relay_2
                    else:
                      - event.trigger:
                          id: switch_event
                          event_type: switch_2

      - timing:
          - ON for 50ms to 350ms
          - OFF for 50ms to 350ms
          - ON for at least 200ms
        then:
          - switch.toggle: decoupled_mode
          - event.trigger:
              id: switch_event
              event_type: failsafe

      - timing:
          - OFF for 50ms to 350ms
          - ON for 50ms to 350ms
          - OFF for at least 200ms
        then:
          - switch.toggle: decoupled_mode
          - event.trigger:
              id: switch_event
              event_type: failsafe

Pinout

Because the built-in button is connected to GPIO4, unlike on other devices, you also need to solder a wire to GPIO0 and pull it to GND to enter flash mode.