No-solder Home Assistant/ESPHome temperature/humidity sensors

esphome-temp-sensors.txt

Components
============================================
~$4 NodeMCUv2 ESP8266 (fairly generic, get wherever's convenient)
~$6 Adafruit SHT40: https://www.adafruit.com/product/4885
~$1 Adafruit StemmaQT to female Dupont cable: https://www.adafruit.com/product/4397
    USB wall wart (Optional, however you power the ESP8266 is fine)
    USB A to micro B (Optional, however you power the ESP8266 is fine)

Assembly
============================================
Plug the StemmaQT cable end into the SHT40 temp sensor (the plug on either side is fine)
Run the red wire to the 3V3 pin on the NodeMCUv2 next to D4
Run the black wire to the GND pin next to the previous 3V3 pin
Run the blue wire to D5
Run the yellow wire to D6 (All four should be in a row now: red, black, blue, yellow)

ESPHome Config
============================================
Add the following to your basic ESPHome config for the sensor (Remove 

esphome:
  name: living_room_temp
  platform: ESP8266
  board: nodemcuv2

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

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "${name} Fallback Hotspot"
    password: !secret wifi_fallback_password

captive_portal:

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:

sensor:
  - platform: wifi_signal
    name: "${name} WiFi Signal"
    update_interval: 60s

  - platform: sht4x
    temperature:
      filters:
        - lambda: return x * (9.0/5.0) + 32.0;
      unit_of_measurement: "°F"
      name: "Living Room Temperature"
    humidity:
      name: "Living Room Humidity"
    update_interval: 60s

i2c:
  sda: D5
  scl: D6

Flash the sensor with ESPHome and add to Home Assistant, and that's it!
If you want temps in Celcius (the default) just remove these two lines from the sensor section:
      filters:
        - lambda: return x * (9.0/5.0) + 32.0;