ESPHome Water Softener Salt Level Sensor

Sometime ago I was searching for a way to monitor the level of salt in my water softener and came across this post using a D1 mini and an Ultrasonic Distance Sensor with ESPHome. I don't have many devices connected to ESPHome, and it is quite sparse only about 5 devices. Some temperature/humidity sensors, a string light switch, a bluetooth proxy, and now this water softener sensor.

The configuration from here was working great until the latest update to ESPHome, mostly my fault because I didn't read the release notes. When I went to update the sensor, I could only get the measurements to return and not the percentage. Come to find out that what was missing was the ability for the trigger pin and echo pin to allow to be reused:

- platform: ultrasonic
  trigger_pin: 
    number: D2
    allow_other_uses: true
  echo_pin: 
    number: D1
    allow_other_uses: true

A few modifications that I made (albeit not sure if it makes any difference) was to set a global variable for the maximum distance detected by the sensor

globals:

 - id: maximum_distance

   type: float

   initial_value: '0.83'

Then also to save the measurement as an id salt_level_measurement to be reused for the calculation of percentage and use the maximum_distance variable:

 - platform: ultrasonic

    trigger_pin: 

      number: D2

      allow_other_uses: true

    echo_pin: 

      number: D1

      allow_other_uses: true

    name: Salt level measurement

    update_interval: 60s

    pulse_time: 200ms

    timeout: 4.0m

    id: salt_level_measurement

    filters:

      - lambda: return (id(maximum_distance)-x)*(100/id(maximum_distance));

      - filter_out: nan

    unit_of_measurement: cm

All in all, it works really well. Here is the complete config file for the sensor, the update time is every 60 seconds which may be overkill, but I'll end up adjusting it if need be. Hope this helps!

api:

  encryption:

    key: "redacted"

captive_portal:

esp8266:

  board: d1_mini

esphome:

  name: ${name}

  friendly_name: ${friendly_name}

globals:

 - id: maximum_distance

   type: float

   initial_value: '0.83'

logger:

ota:

  password: "redacted"

sensor:

  - platform: uptime

    name: salt_level_sensor Uptime

  - platform: wifi_signal

    name: salt_level_sensor WiFi Signal

    update_interval: 60s

  - platform: ultrasonic

    trigger_pin: 

      number: D2

      allow_other_uses: true

    echo_pin: 

      number: D1

      allow_other_uses: true

    name: Salt level measurement

    update_interval: 60s

    pulse_time: 200ms

    timeout: 4.0m

    id: salt_level_measurement

    filters:

      - lambda: return (id(maximum_distance)-x)*(100/id(maximum_distance));

      - filter_out: nan

    unit_of_measurement: cm

  - platform: ultrasonic

    trigger_pin: 

      number: D2

      allow_other_uses: true

    echo_pin: 

      number: D1

      allow_other_uses: true

    name: Salt level percent

    update_interval: 60s

    pulse_time: 200ms

    timeout: 4.0m

    filters:

      - lambda: return (id(maximum_distance)-x)*100;

      - filter_out: nan

    unit_of_measurement: "%"

substitutions:

  name: salt-level-sensor

  friendly_name: Water Softener

switch:

  - platform: restart

    name: salt_level_sensor Restart

text_sensor:

  - platform: version

    name: salt_level_sensor ESPHome Version

  - platform: wifi_info

    ip_address:

      name: salt_level_sensor IP

    ssid:

      name: salt_level_sensor SSID

    bssid:

      name: salt_level_sensor BSSID

time:

  - platform: homeassistant

    id: homeassistant_time

web_server:

  port: 80

wifi:

  ssid: !secret wifi_ssid

  password: !secret wifi_password

  ap:

    ssid: "Salt-Level-Sensor"

    password: "redacted"