ESPHome Rain Sensor

esphome-web-rain-sensor.yaml

# This is an ESPHome configuration for an Outdoor Weather Station.
# The configuration includes a raindrop coverage sensor and a rain sensor.
# The raindrop coverage sensor uses an ADC to measure water resistance,
# while the rain sensor is a digital sensor indicating whether it is raining or not.
#
# The configuration uses substitutions to define all the configurable parts,
# making it easy to adjust pins and other settings without modifying the entire file.

substitutions:
  name: esph-29697f-ows-1
  friendly_name: Outdoor Weather Station (ESPH-29697f)
  board: nodemcuv2
  pin_power: D7
  pin_rs_analog: A0
  pin_rs_digital: D2

# Define the name and friendly name for the ESPHome device
esphome:
  name: ${name}
  friendly_name: ${friendly_name}
  name_add_mac_suffix: false
  project:
    name: esphome.web
    version: '1.0'

# Specify the ESP8266 board being used
esp8266:
  board: ${board}

# Enable logging, Home Assistant API, OTA updates, Improv Serial, and Web Server
logger: # Enable logging and other configuration
api: # Enable Home Assistant API
ota: # Allow Over-The-Air updates
improv_serial: # Allow provisioning Wi-Fi via serial
web_server: # To have a "next url" for improv serial

# Configure Wi-Fi settings
wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

# Import the dashboard configuration from an example GitHub repo
dashboard_import:
  package_import_url: github://esphome/example-configs/esphome-web/esp8266.yaml@main
  import_full_config: true

# --------------------------------------------------------------------------------------------

# Define sensors
sensor:
  - platform: adc
    pin: ${pin_rs_analog}  # Analog pin connected to the water resistance sensor
    id: water_resistance  # Internal ID for the water resistance sensor
    internal: true  # This sensor is used internally and won't be exposed to Home Assistant
    filters:
      - calibrate_linear: # Linear calibration to trim erroneous 5% edges
          - 0.05 -> 0.0
          - 0.95 -> 100.0
  
  - platform: template
    name: "Raindrop Coverage Sensor"  # Name exposed to Home Assistant
    id: raindrop_coverage_sensor  # Internal ID for the raindrop coverage sensor
    accuracy_decimals: 1  # Display one decimal place
    unit_of_measurement: "%"  # Unit of measurement as a percentage
    icon: "mdi:water-percent"  # Icon representing water percentage

# Define binary sensor
binary_sensor:
  - platform: template
    name: "Rain Sensor"  # Name exposed to Home Assistant
    id: rain_sensor  # Internal ID for the rain sensor
    device_class: moisture  # Device class for moisture detection
    icon: "mdi:umbrella"  # Icon representing an umbrella

# Define interval to read data every 5 seconds and update the sensors
# This is done to save power and extend the sensor's longevity by only powering
# the sensors when necessary, instead of allowing each sensor to directly read continuously.
interval:
  - interval: 5s
    then:
      - output.turn_on: sensor_power  # Turn on the power to the sensor
      - delay: 10ms  # Wait for 10 milliseconds
      - component.update: water_resistance  # Update the water resistance sensor reading
      - sensor.template.publish:
          id: raindrop_coverage_sensor
          state: !lambda |-
            // Invert the water resistance state and constrain between 0 and 100
            return std::max(0.0, std::min(100.0, 100.0 - id(water_resistance).state));
      - lambda: |-
          // Read the digital rain sensor state and publish it
          bool rain_state = !digitalRead(${pin_rs_digital});
          id(rain_sensor).publish_state(rain_state);
      - delay: 10ms  # Wait for 10 milliseconds
      - output.turn_off: sensor_power  # Turn off the power to the sensor

# Define the output to control sensor power
output:
  - platform: gpio
    pin: ${pin_power}  # GPIO pin used to control the power to the sensor
    id: sensor_power  # Internal ID for the power control