SONOFF S31

One of the top favorite smart plugs. Easy to disassemble with a screw driver, exposed pin headers to the ESP8266, button on GPIO 0, and excellent power monitoring! You can even flash it without soldering utilizing a USB TTL adapter and dupont test clips known as clippy bois - see the pics section below.

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Video Setup

Tasmota Template

None needed as it is built into TASMOTA. Click Configuration -> Configure Module -> Pick SONOFF S31 and hit Save.

TASMOTA Settings

The power calibration for the S31 is usually pretty close on default but it can be fine tuned via Tasmota Calibration Procedure

GPIO Layout

GPIO	Component	Description
GPIO00	Button 1
GPIO01	CSE7766 Tx	Power monitoring chip
GPIO03	CSE7766 Rx	Power monitoring chip
GPIO12	Relay1	Relay for Load
GPIO13	Led_i_1	Onboard LED

ESPHome YAML

# Basic Config
esphome:
  name: sonoff_s31
  platform: ESP8266
  board: esp01_1m

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

logger:
  baud_rate: 0 # (UART logging interferes with cse7766)
  
api:
ota:

uart:
  rx_pin: RX
  baud_rate: 4800

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: cse7766
    current:
      name: "Sonoff S31 Current"
      accuracy_decimals: 1
    voltage:
      name: "Sonoff S31 Voltage"
      accuracy_decimals: 1
    power:
      name: "Sonoff S31 Power"
      accuracy_decimals: 1
      id: my_power
  - platform: total_daily_energy
    name: "Sonoff S31 Daily Energy"
    power_id: my_power

switch:
  - platform: gpio
    name: "Sonoff S31 Relay"
    pin: GPIO12
    id: relay
    restore_mode: ALWAYS_ON

status_led:
  pin:
    number: GPIO13
    inverted: True

Pics