EspHome lambda needed,not HA automation

Hello and sorry about my english.How can i do (in Esphome , not HA automation) a sensor(counter),witch counts pellet consumption .My esp device turns auger on and off,so it knows,when and how long auger works.And i know pellet consumption for 3 minutes of continiously work-it is 210 grams.So i need some lambda i think?

Something like:

  - platform: template
    name: "Pellets"
    id: pellet_counter
    step: 3.5  # grams per 3 sec (interval in on_time: below)
    device_class: weight
    units_of_measurement: "g"

  - platform: homeassistant
    id: homeassistant_time
      - seconds: /3
            - if:
                  switch.is_on: auger_switch  # id of the auger control
                  - number.increment:
                      id: pellet_counter
                      cycle: false

Untested but should be a start. Didn’t need lambda - sorry.

You will need something to set the value to zero if you refill pellets. Have a look at Number Components in the doco.