Monitoring Water Usage with Home Assistant and ESPHome

esphome:
  name: esphome-water-meter-6a1574
  friendly_name: ESPHome Water Meter 6a1574

esp32:
  board: esp32dev
  framework:
    type: arduino

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "LnsJ9vEC1+wGzbAkWzdM7zuMNGLhVs3NaE/MHv9L5FM="

i2c:
  sda: GPIO13
  scl: GPIO16
  scan: True

ota:
  - platform: esphome

web_server:


ethernet:
  type: LAN8720
  mdc_pin: GPIO23
  mdio_pin: GPIO18
  clk_mode: GPIO17_OUT
  phy_addr: 0
  power_pin: GPIO12

number:
  - platform: template
    name: "ESPHome Water Meter 6a1574 Set Reading"
    optimistic: True
    min_value: 0
    max_value: 999999
    step: 0.001
    id: act_reading
    entity_category: config
    mode: box
    icon: 'mdi:counter'
    set_action:
      then:
        - lambda: |-
            int d;
            d = floor(x);
            id(water_counter_total) = d ;

# QMC5883L Sensor Configuration #
# https://esphome.io/components/sensor/qmc5883l.html

globals:
  - id: water_counter_total # increasing count
    type: long
    restore_value: yes
    initial_value: '0'
  - id: water_counter  # current count
    type: long
    restore_value: no
    initial_value: '0'
  - id: water_high # high/low threshold for count
    type: bool
    restore_value: no
    initial_value: 'false'

interval: # set both the high and low thresholds below for a trigger.  Y-Axiz range -69 to -121 when cycling slowly.  Using -65 to -55.
  - interval: 10ms # this is why the water meter was slipping, 250 ms was way too slow.
    then:
    - lambda: |-
       if (id(qmc5883l_y).state > -60 && !id(water_high)) {
          id(water_counter_total) += 1;
          id(water_counter) += 1; 
          id(water_high) = true;
        } else if (id(qmc5883l_y).state < -75 && id(water_high)) {
          id(water_high) = false;
        } 

sensor:
  - platform: qmc5883l
    address: 0x0D
#    field_strength_x:
#      name: "QMC5883L X-axis" # Not using.
#      id: qmc5883l_x
    field_strength_y:
      name: "QMC5883L Y-axis" # Using this one, hide others.
      id: qmc5883l_y
      internal: true # Change to false if you need to see readings.  This will log a ton of data.
#    field_strength_z:
#      name: "QMC5883L Z-axis" # Not using.
#      id: qmc5883l_z
  # heading:
   #  name: "qMC5883L Heading" # once I have the best X, Y, or Z sensor for reading the meter, I can comment out the other two sensors as well.
    oversampling: 128x # 512x (default), 256x, 128x, 64x (give other settings a try, see if it reduces noise)
    range: 200uT # 200 uT, 800 uT
    update_interval: 10ms # Make sure to also set calculation interval above too!

# Oversampling rate is tied to refresh:
# 512x = 10 Hz
# 256x = 50 Hz
# 128x = 100 Hz
# 64x = 200 Hz

# QMC5883L has a maximum output of 200 Hz.
# Can read at 10, 50, 100 or 200 Hz:
# 200 Hz = 5ms
# 100 Hz = 10ms
# 50 Hz = 20ms
# 10 Hz = 100ms

# “maximum 75 pulses/second on 5/8” T10" (another source below claims 77 pulses/sec)
# The reed switch in the meter generates 2X pulses per rotation.
# My magnetometer generates 1X waveform per rotation.  I get half the pulses of a reed switch.
# 77 pulses per second /2 x 60 = 2310 rpm.
# 75 pulses per second /2 x 60 = 2250 rpm.

# Sampling a waveform should be 2X or more, so at least 77 Hz which is 12.98ms
# The next compatible HARDWARE sample rate above 77 Hz is 100 Hz or 10ms.

  - platform: template
    name: "Nutating Disc Count" # This works, doesn't miss a drop from low to high flows.
    lambda: |-
      float temp1 = id(water_counter_total);
      return temp1;
    update_interval: 1s
    state_class: 'total_increasing'
    accuracy_decimals: 0

  - platform: template
    name: "Nutating Disc RPM" # this seems to work, number is plausible.
    lambda: |-
      int temp2 = id(water_counter);
      id(water_counter) -= temp2;
      return temp2 * (6);
    update_interval: 10s
    unit_of_measurement: "rpm"
    accuracy_decimals: 0

  - platform: template
    name: "Water Flow L/min"
    lambda: |-
      int temp3 = id(water_counter);
      id(water_counter) -= temp3;
      return temp3 * (6 * 0.032736241);
    update_interval: 10s
    unit_of_measurement: "L/min"
    accuracy_decimals: 2

  - platform: template
    name: "Water Total (L)" # This works, doesn't miss a drop from low to high flows.
    lambda: |-
      return ((float)id(water_counter_total) * (0.032736241));
    update_interval: 10s
    unit_of_measurement: 'L'
    accuracy_decimals: 2
    state_class: 'total_increasing'
    device_class: 'water'

  - platform: template
    name: "Water Total (m³)" # This works, doesn't miss a drop from low to high flows.
    lambda: |-
      return ((float)id(water_counter_total) * (0.032736241 * 0.001));
    update_interval: 60s
    unit_of_measurement: 'm³'
    accuracy_decimals: 3
    state_class: 'total_increasing'
    device_class: 'water'    

# 5/8" Neptune T-10 Calibration:
# Source: https://www.riotronics.com/wp-content/uploads/2019/11/NT10-4P-WaterRead-pdf3.01.pdf
# Riotronics makes a device that fits between the meter head and the base, they say:
# 0.004324 gallons per pulse
# 231.24 pulses per gallon
# Max 20 gpm or 77 pulses/sec
# My sensor gets 1/2 the pulses of a reed switch.  See below.
# In metric:
# 0.032736241 L per rotation
# 30.54718459 rotations per litre
# 0.000032736 m3 per rotation

# A rotating magnet next to a reed switch results in 2X closes per revolution.
# When the magnet axis is parallel, the switch closes.
# When the magnet axis is perpendicular, the switch opens.
# Although the poles reverse, they still induce opposite poles in the reed switch.
# A reed switch is an omni-polar device.