EDIT: The YAML has changed over time as I make improvements and corrections. I am not rewriting this post as for the most part it is still correct (if not let me know) but keep in mind the YAML at the bottom of the post has evolved a bit compared to what you see in this first post.
I found a basic version of the code below for the Sonoff S31 and made a number of improvements, at least for my use scenario. I rely a lot on people sharing so I wanted to share back in case it helps others. I had started off with Tasmota and really liked the fact the outlet had a web interface and how much information was available for each device. What I did not like was the complexity of setting it all up due to MQTT being in the middle. It was not difficult but it felt unnecessarily complicated when ESPHome has a more direct integration. Anyway this thread is not meant o be a debate between ESPHome and Tasmota so back to the YAML:
This is the entire code needed:
substitutions:
devicename: s31-outlet-1
friendly_devicename: "Office Equipment Outlet"
# Basic Config
esphome:
name: ${devicename}
platform: ESP8266
board: esp01_1m
The substitutions section allows to define variables so that you donât have to edit the YAML in many places each time you create a new device using this YAML or simply make a change.
The devicename needs to be short and a unique identifier. I would set it, and leave it, named as you named the configuration in ESPHome when you created the device. For some reason I run into issues (device not found, etc.) if I mess with it. This is also how this device will be named on the Integration page under ESPHome (but you can rename it there if you really want to), and will be the default device name in Home Assistant (which we will change).
The friendly_devicename is what you will call the device. This device is an outlet so I would recommend naming it with the name of the device attached to the outlet, or blah blah outlet in the event the outlet is powering has multiple devices. This is important as it will determine what all the other entities will be named and will save you lots of entity editing later.
wifi:
ssid: !secret iot_wifi_ssid
password: !secret iot_wifi_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "${devicename} Hotspot"
password: !secret iot_wifi_password
When you see !secret it is referring to a variable in your secrets.yaml file which can be edited directly from within ESPHome (top right of window). Just add the following editing in your details:
# Your IOT Wi-Fi SSID and password
iot_wifi_ssid: "IoT_ SSID_ here"
iot_wifi_password: "password_here"
I really wanted to see some device information when loading up the IP of the device in a web browser like Tasmota. While not as fancy, a lot can be shown on ESPDevices just by adding a few lines of YAML. I donât know what include_internal: true actually does as I donât believe I saw a difference with or without it, but it doesnât seem to be causing issues so I left it.
web_server:
port: 80
include_internal: true
Whether needed or not, I wanted to see all connectivity variables as entities for easier troubleshooting. When you start having lots of devices this is handy. Here we see the ${friendly_devicename} variable which will give the entities a name that includes the device name.
text_sensor:
- platform: wifi_info
ip_address:
name: "${friendly_devicename}: IP"
icon: "mdi:ip-outline"
ssid:
name: "${friendly_devicename}: SSID"
icon: "mdi:wifi-settings"
bssid:
name: "${friendly_devicename}: BSSID"
icon: "mdi:wifi-settings"
mac_address:
name: "${friendly_devicename}: MAC"
icon: "mdi:network-outline"
scan_results:
name: "${friendly_devicename}: Wifi Scan"
icon: "mdi:wifi-refresh"
disabled_by_default: true
This is how it will look in HA:
In the example above, only IP will appear on the device page but on a dashboard it will sow as Office Equipment Outlet: IP.
Same thing for the Controls and Sensors of the device. In the sensor section I changed the Energy over time from W (which I believe was showing with 3 decimals which was a bit silly) to kW with 3 decimals. I would argue that seeing anything under 1W is really meaningless and probably not even very accurate for this kind of device. If you set it to kW the numbers will be smaller and you will still see down to the 1W granularity. For those wanting to figure out the cost of the power used, this makes it a tiny bit simpler since power is sold by the kWh. Before this change, 2.345kW was showing as 2,345.678W. I would argue that the 1 decimal accuracy for voltage and power are also pointless but I left them since almost all other devices show that or more.
sensor:
- platform: wifi_signal
name: "${friendly_devicename}: WiFi Signal"
update_interval: 60s
- platform: cse7766
current:
name: "${friendly_devicename}: Current"
accuracy_decimals: 1
voltage:
name: "${friendly_devicename}: Voltage"
accuracy_decimals: 1
power:
name: "${friendly_devicename}: Power"
accuracy_decimals: 1
id: my_power
- platform: total_daily_energy
name: "${friendly_devicename}: Daily Energy"
power_id: my_power
filters:
# Multiplication factor from W to kW is 0.001
- multiply: 0.001
unit_of_measurement: kW
No changes here, but I believe the restore_mode: ALWAYS_ON is what makes the outlet turn on immediately after being powered up.
switch:
- platform: gpio
name: "${friendly_devicename}"
icon: "mdi:power-socket-us"
pin: GPIO12
id: relay
restore_mode: ALWAYS_ON
If this doesnât work for you, the other options should be here:
I have not tested these yet, but the page above lists these as options:
* **restore_mode** (*Optional*): Control how the GPIO Switch attempts to restore state on bootup. For restoring on ESP8266s, also see `restore_from_flash` in the [esp8266 section](https://esphome.io/components/esp8266.html).
> * `RESTORE_DEFAULT_OFF` (Default) - Attempt to restore state and default to OFF if not possible to restore.
> * `RESTORE_DEFAULT_ON` - Attempt to restore state and default to ON.
> * `RESTORE_INVERTED_DEFAULT_OFF` - Attempt to restore state inverted from the previous state and default to OFF.
> * `RESTORE_INVERTED_DEFAULT_ON` - Attempt to restore state inverted from the previous state and default to ON.
> * `ALWAYS_OFF` - Always initialize the pin as OFF on bootup.
> * `ALWAYS_ON` - Always initialize the pin as ON on bootup.
I read this part is needed if you want the energy measurement kWh to be reset daily. In most cases you either need a time/date from the start of the measurement, or just reset it daily. I would like a start time/date as Tasmota offered and a way to reset it as needed. Iâll research this to see if it is possible from within the device YAML itself.
time:
- platform: sntp
id: my_time
Full YAML you can try here: 
Edit: see further down for updated full YAML
substitutions:
devicename: s31-outlet-1
friendly_devicename: "Office Equipment Outlet"
# Basic Config
esphome:
name: ${devicename}
platform: ESP8266
board: esp01_1m
wifi:
ssid: !secret iot_wifi_ssid
password: !secret iot_wifi_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "${devicename} Hotspot"
password: !secret iot_wifi_password
logger:
baud_rate: 0 # (UART logging interferes with cse7766)
# Remove this line if you're not using Home Assistsant or your switch will restart every now and again
api:
ota:
web_server:
port: 80
include_internal: true
# Device Specific Config
uart:
rx_pin: RX
baud_rate: 4800
text_sensor:
- platform: wifi_info
ip_address:
name: "${friendly_devicename}: IP"
icon: "mdi:ip-outline"
ssid:
name: "${friendly_devicename}: SSID"
icon: "mdi:wifi-settings"
bssid:
name: "${friendly_devicename}: BSSID"
icon: "mdi:wifi-settings"
mac_address:
name: "${friendly_devicename}: MAC"
icon: "mdi:network-outline"
scan_results:
name: "${friendly_devicename}: Wifi Scan"
icon: "mdi:wifi-refresh"
disabled_by_default: true
binary_sensor:
- platform: gpio
pin:
number: GPIO0
mode: INPUT_PULLUP
inverted: True
name: "${friendly_devicename}: Button"
on_press:
- switch.toggle: relay
- platform: status
name: "${friendly_devicename}: Status"
sensor:
- platform: wifi_signal
name: "${friendly_devicename}: WiFi Signal"
update_interval: 60s
- platform: cse7766
current:
name: "${friendly_devicename}: Current"
accuracy_decimals: 1
voltage:
name: "${friendly_devicename}: Voltage"
accuracy_decimals: 1
power:
name: "${friendly_devicename}: Power"
accuracy_decimals: 1
id: my_power
- platform: total_daily_energy
name: "${friendly_devicename}: Daily Energy"
power_id: my_power
filters:
# Multiplication factor from W to kW is 0.001
- multiply: 0.001
unit_of_measurement: kW
switch:
- platform: gpio
name: "${friendly_devicename}"
icon: "mdi:power-socket-us"
pin: GPIO12
id: relay
restore_mode: ALWAYS_ON
time:
- platform: sntp
id: my_time
status_led:
pin: GPIO13
Thank you to all those who have helped me on HA stuff! I hope this counts as giving back a little 
Disclaimer: As mentioned above, I found most of this code online (sorry I forgot where) and just customized it a bit. Not claiming any authorship!
I would now add the device leaving the name that matches what it is called in ESPHome. Once added, go to the device to make one last change. There I would only change the device name on the top left to match what you used in the friendly_devicename variable. In the example above it is Office Equipment Outlet. Doing so will make your device page look like this without further editing:
Most of the time I end up having to edit every single entity for it to be named following what I adopted as my standard. With this YAML I donât and it has become much easier to add/remove. In fact, if you end up with other entities under this device that you want to get rid of (I did while making changes), just delete it from the ESPHome Integration (only the integration!!!) and add it back (Add integration, select ESPHome, and enter IP).
The only entity that I set as disabled by default is the Wifi Scan one that shows all the APs it receives. Itâs unnecessary in most cases⌠you may want it only if you have connectivity issues and want to see what it receives.
This is how it will show up in ESPHome⌠too bad one canât add a descriptor.
Last, the web interface (default view)âŚ
LATEST VERSION OF THE FULL YAML
UPDATED: 05-JUL-2022
For information on changes please refer to the posts in this thread.:
substitutions:
devicename: s31-outlet-1
devicename_no_dashes: s31_outlet_1
friendly_devicename: "Office Equipment Outlet"
restore_mode_setting: RESTORE_DEFAULT_ON
#restore_mode: Control how the relay attempts to restore state on bootup.
#RESTORE_DEFAULT_OFF - Attempt to restore state and default to OFF if not possible to restore.
#RESTORE_DEFAULT_ON - Attempt to restore state and default to ON.
#RESTORE_INVERTED_DEFAULT_OFF - Attempt to restore state inverted from the previous state and default to OFF.
#RESTORE_INVERTED_DEFAULT_ON - Attempt to restore state inverted from the previous state and default to ON.
#ALWAYS_OFF - Always initialize the pin as OFF on bootup.
#ALWAYS_ON - Always initialize the pin as ON on bootup.
# Basic Config
esphome:
name: ${devicename}
platform: ESP8266
board: esp01_1m
wifi:
ssid: !secret iot_wifi_ssid
password: !secret iot_wifi_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "${devicename} Hotspot"
password: !secret iot_wifi_password
logger:
baud_rate: 0 # (UART logging interferes with cse7766)
# Remove this line if you're not using Home Assistsant or your switch will restart every now and again
api:
ota:
web_server:
port: 80
include_internal: true
# Device Specific Config
uart:
rx_pin: RX
baud_rate: 4800
text_sensor:
- platform: wifi_info
ip_address:
name: "${friendly_devicename}: IP"
icon: "mdi:ip-outline"
ssid:
name: "${friendly_devicename}: SSID"
icon: "mdi:wifi-settings"
bssid:
name: "${friendly_devicename}: BSSID"
icon: "mdi:wifi-settings"
mac_address:
name: "${friendly_devicename}: MAC"
icon: "mdi:network-outline"
scan_results:
name: "${friendly_devicename}: Wifi Scan"
icon: "mdi:wifi-refresh"
disabled_by_default: true
binary_sensor:
- platform: gpio
pin:
number: GPIO0
mode: INPUT_PULLUP
inverted: True
name: "${friendly_devicename}: Button"
on_press:
- switch.toggle: relay
- platform: status
name: "${friendly_devicename}: Status"
sensor:
- platform: wifi_signal
name: "${friendly_devicename}: WiFi Signal"
update_interval: 60s
- platform: cse7766
current:
name: "${friendly_devicename}: Current"
state_class: measurement
device_class: current
unit_of_measurement: A
accuracy_decimals: 1
voltage:
name: "${friendly_devicename}: Voltage"
state_class: measurement
device_class: voltage
unit_of_measurement: V
accuracy_decimals: 1
power:
name: "${friendly_devicename}: Power"
id: "${devicename_no_dashes}_power"
state_class: measurement
device_class: power
unit_of_measurement: W
accuracy_decimals: 1
- platform: total_daily_energy
name: "${friendly_devicename}: Daily Energy"
power_id: "${devicename_no_dashes}_power"
filters:
# Multiplication factor from W to kW is 0.001
- multiply: 0.001
unit_of_measurement: kW
state_class: total_increasing
device_class: energy
# 3 shows each W consumed, 2 every 10W, 1 every 100W
accuracy_decimals: 1
switch:
- platform: gpio
name: "${friendly_devicename}"
icon: "mdi:power-socket-us"
pin: GPIO12
id: relay
restore_mode: ${restore_mode_setting}
time:
- platform: sntp
id: my_time
status_led:
pin: GPIO13