Kamstrup Omnipower Smart-Meter Readings using EspHome and Esp-now

gistfile1.txt

# ESPHome for a Lolin S3 Mini on the HAN port of a Kamstrup Omnipower.
# Powered from the meter (HAN); a supercapacitor buffers energy — no battery.
# Reads DLMS telegrams (power/energy import+export) and sends them via
# ESP-NOW to the hub. Radio stays off until it is time to transmit.
# Capacitor check before metering: voltage too low → short sleep to recharge.
# Otherwise wait for a telegram (or timeout), send, then deep sleep until the next slot.
#
# LED: brief blue if capacitor is OK, red if voltage is too low, green after telegram, off in sleep.
# Flow: radio off → capacitor check → DLMS → ESP-NOW → sleep.
# Capacitor < ${min_capacitor_voltage}: sleep ${charging_sleep_duration_seconds}s immediately (capacitor charges, no radio).
# Timeout: after ${run_duration_seconds} send whatever is available and sleep.
# HAN transmits every 10 s. Sleep of exactly 60 s plus finish overhead wakes just after
# the slot, then wait ~10 s. So sleep a minute minus 3–5 s (55–57 s). 58–59 s plus
# frame/boot (~2 s) slips past T+60.

substitutions:
  name: kamstrup-omnipower-02
  friendly_name: "Kamstrup Omnipower 02"
  run_duration_seconds: "15"
  sleep_duration_minutes: "1"
  espnow_channel: "1"
  min_capacitor_voltage: "3.80"
  charging_sleep_duration_seconds: "90"
  led_brightness: "50%"
  obis_power_import: "1.1.1.7.0.255"
  obis_power_export: "1.1.2.7.0.255"
  obis_energy_import: "1.1.1.8.0.255"
  obis_energy_export: "1.1.2.8.0.255"

esphome:
  name: ${name}
  friendly_name: ${friendly_name}
  includes:
    - common/rtc_wakeup_count.h
  on_boot:
    - priority: 300
      then:
        - lambda: |-
            id(wakeup_cycle_count) = bump_wakeup_count();
            id(wakeup_count).publish_state(id(wakeup_cycle_count));
            ESP_LOGI("boot", "Wake-up cycle %d (reset %d)", id(wakeup_cycle_count), (int) esp_reset_reason());
        - script.execute: sleep_if_capacitor_low
        - script.wait: sleep_if_capacitor_low
        - light.turn_on:
            id: onboard_rgb
            red: 0%
            green: 0%
            blue: 100%
            brightness: ${led_brightness}
            transition_length: 0s
        - delay: 200ms
        - light.turn_off:
            id: onboard_rgb
            transition_length: 0s
        - lambda: "id(boot_ready) = true;"

esp32:
  board: lolin_s3_mini
  cpu_frequency: 80MHz
  framework:
    type: esp-idf

logger:

espnow:
  id: espnow_id
  channel: ${espnow_channel}
  auto_add_peer: false
  enable_on_boot: false  # radio stays off until finish_and_sleep
  peers:
    - !secret espnow_hub_mac

packet_transport:
  - platform: espnow
    id: transport
    espnow_id: espnow_id
    peer_address: !secret espnow_hub_mac
    encryption: !secret espnow_transport_key
    update_interval: never
    sensors:
      - power_import
      - power_export
      - energy_import
      - energy_export
      - battery_voltage
      - uptime_seconds
      - wakeup_count

globals:
  - id: wakeup_cycle_count
    type: int
    restore_value: no
    initial_value: "0"
  # finish_and_sleep only after capacitor check and blue LED.
  - id: boot_ready
    type: bool
    restore_value: no
    initial_value: "false"

deep_sleep:
  id: deep_sleep_control
  sleep_duration: ${sleep_duration_minutes}min

interval:
  - interval: 1s
    id: force_sleep_interval
    then:
      - if:
          condition:
            and:
              - not:
                  script.is_running: finish_and_sleep
              - lambda: "return millis() / 1000 >= ${run_duration_seconds};"
          then:
            - logger.log:
                level: INFO
                format: "Max run duration reached, sending ESP-NOW and sleeping"
            - script.execute: finish_and_sleep

uart:
  id: uart_dlms_bus
  rx_pin: GPIO44
  baud_rate: 2400
  data_bits: 8
  parity: NONE
  stop_bits: 1
  rx_buffer_size: 1024

dlms_meter:
  id: dlms_meter_hub
  uart_id: uart_dlms_bus
  auth_key: !secret dlms_auth_key
  decryption_key: !secret dlms_decryption_key
  # 500 ms idle: 200 ms was too short and parsed frames already during on_boot.
  receive_timeout: 500ms

script:
  - id: sleep_if_capacitor_low
    mode: single
    then:
      - component.update: battery_voltage
      - delay: 80ms
      - if:
          condition:
            lambda: |-
              float v = id(battery_voltage).state;
              return std::isnan(v) || v < ${min_capacitor_voltage}f;
          then:
            - logger.log:
                level: WARN
                format: "Capacitor %.2f V < ${min_capacitor_voltage} V, sleeping ${charging_sleep_duration_seconds}s to charge"
                args: ["id(battery_voltage).state"]
            - light.turn_on:
                id: onboard_rgb
                red: 100%
                green: 0%
                blue: 0%
                brightness: ${led_brightness}
                transition_length: 0s
            - delay: 200ms
            - light.turn_off:
                id: onboard_rgb
                transition_length: 0s
            - delay: 50ms
            - deep_sleep.enter:
                id: deep_sleep_control
                sleep_duration: !lambda "return ${charging_sleep_duration_seconds} * 1000;"

  - id: finish_and_sleep
    mode: single
    then:
      - wait_until:
          condition:
            lambda: "return id(boot_ready);"
          timeout: 10s
      - logger.log:
          level: INFO
          format: "Finishing and sleeping"
      - light.turn_on:
          id: onboard_rgb
          red: 0%
          green: 100%
          blue: 0%
          brightness: ${led_brightness}
          transition_length: 0s
      - component.update: uptime_seconds
      - delay: 50ms
      - component.update: wakeup_count
      - delay: 50ms
      - lambda: |-
          id(espnow_id).enable();
      - delay: 150ms
      - component.update: transport
      - logger.log:
          level: INFO
          format: "Everything sent, turning off LED and sleeping"
      - light.turn_off:
          id: onboard_rgb
          transition_length: 0s
      - delay: 100ms
      # Minute minus 3–5 s (55–57 s). 58–59 s + frame/finish/boot often slips past the slot.
      - deep_sleep.enter:
          id: deep_sleep_control
          sleep_duration: !lambda |-
            const uint32_t jitter_s = 3 + (random_uint32() % 3);
            const uint32_t sleep_s = ${sleep_duration_minutes} * 60U - jitter_s;
            ESP_LOGI("sleep", "Deep sleep %u s (HAN phase dither)", sleep_s);
            return sleep_s * 1000;

sensor:
  - platform: template
    id: wakeup_count
    internal: true
    accuracy_decimals: 0
    update_interval: never
    lambda: "return id(wakeup_cycle_count);"

  - platform: uptime
    id: uptime_seconds
    type: seconds
    internal: true
    update_interval: never

  - platform: dlms_meter
    id: power_import
    dlms_meter_id: dlms_meter_hub
    obis_code: "${obis_power_import}"
    internal: true
    accuracy_decimals: 0
    on_value:
      then:
        - script.execute: finish_and_sleep

  - platform: dlms_meter
    id: power_export
    dlms_meter_id: dlms_meter_hub
    obis_code: "${obis_power_export}"
    internal: true
    accuracy_decimals: 0
    on_value:
      then:
        - script.execute: finish_and_sleep

  - platform: dlms_meter
    id: energy_import
    dlms_meter_id: dlms_meter_hub
    obis_code: "${obis_energy_import}"
    internal: true
    accuracy_decimals: 3
    filters:
      - multiply: 0.001
    on_value:
      then:
        - script.execute: finish_and_sleep

  - platform: dlms_meter
    id: energy_export
    dlms_meter_id: dlms_meter_hub
    obis_code: "${obis_energy_export}"
    internal: true
    accuracy_decimals: 3
    filters:
      - multiply: 0.001
    on_value:
      then:
        - script.execute: finish_and_sleep

  - platform: adc
    pin: GPIO4
    name: "Battery Voltage"
    id: battery_voltage
    attenuation: 12db
    samples: 16
    sampling_mode: avg
    unit_of_measurement: "V"
    device_class: voltage
    accuracy_decimals: 1
    entity_category: diagnostic
    update_interval: never
    filters:
      - multiply: 2.022653721682848
      - round: 1

light:
  - platform: esp32_rmt_led_strip
    channel_colors: RGB
    pin: GPIO47
    num_leds: 1
    chipset: ws2812
    id: onboard_rgb
    internal: true
    restore_mode: ALWAYS_OFF