Sonoff S31

Initial Install

This device cannot be converted to ESPHome using tuya-convert.

You must remove the cover and use the serial header for first upload. Hold down the button while powering on the device to put it into bootloader mode.

GPIO Pinout

Pin	Function
GPIO0	Push Button (HIGH = off, LOW = on)
GPIO12	Relay and its status LED
GPIO13	Green LED (HIGH = off, LOW = on)
GPIO1	RX pin (for external sensors)
GPIO3	TX pin (for external sensors)

Basic Configuration

# Basic Config
esphome:
  name: sonoff_s31

esp8266:
  board: esp12e
  early_pin_init: false

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

# Remove the following line if you're not using Home Assistant or your switch will restart every now and again
api:

ota:
  platform: esphome

# Device Specific Config

logger:
  baud_rate: 0 # (UART logging interferes with cse7766)
  logs:
    sensor: DEBUG # (Overide any global setting, to VERBOSE will spamming the cse7766 sensors)

uart:
  rx_pin: RX
  baud_rate: 4800
  parity: EVEN

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO0
      mode: INPUT_PULLUP
      inverted: True
    name: "Sonoff S31 Button"
    on_press:
      - switch.toggle: relay
  - platform: status
    name: "Sonoff S31 Status"

sensor:
  - platform: wifi_signal
    name: "Sonoff S31 WiFi Signal"
    update_interval: 60s
  - platform: cse7766
    current:
      name: "Sonoff S31 Current"
      accuracy_decimals: 2
      filters:
        - throttle_average: 60s
    voltage:
      name: "Sonoff S31 Voltage"
      accuracy_decimals: 2
      filters:
        - throttle_average: 60s
    power:
      name: "Sonoff S31 Power"
      accuracy_decimals: 2
      id: my_power
      filters:
        - throttle_average: 60s
    energy:
      name: "Sonoff S31 Energy"
      accuracy_decimals: 2
      filters:
        - throttle: 60s
    apparent_power: #(only available with version 2024.3.0 or greater)
      name: "Sonoff S31 Apparent Power"
      filters:
        - throttle_average: 60s
    power_factor: #(only available with version 2024.3.0 or greater)
      name: "Sonoff S31 Power Factor"
      accuracy_decimals: 2
      filters:
        - throttle_average: 60s

  - platform: total_daily_energy #(Optional, not specific to cse7766)
    name: "Sonoff S31 Daily Energy"
    power_id: my_power
    accuracy_decimals: 2

switch:
  - platform: gpio
    name: "Sonoff S31 Relay"
    pin: GPIO12
    id: relay
    restore_mode: ALWAYS_OFF # Powering the relay may cause damage or instability when the programmer is supplying Vcc.

time:
  - platform: sntp #(required for total_daily_energy)
    id: my_time

status_led:
  pin:
    number: GPIO13
    inverted: True

Warnings

• board: esp12e is required to enable all 4MB of flash, allowing OTA updates to work after approximately version 2024.4.0
• throttle_average: 60s on cse7766 sensors is highly recommended with version 2024.2.0 or greater.
• restore_mode: ALWAYS_OFF avoids potential damage or instability when using the programmer’s supply.
• web_server: can cause instability due to the device's slower ESP8266 processor