ESPHome - Pulse Counter

Working on adding a water meter to Home Assistant, using an ESP32.
There is sample code available, but I can’t get it to work, as my GPIO Pin (13) always ends up “high” after boot, but I need it to be low, as my water sensor provides a high signal.
Here’s my (very basic) code:

sensor:
  - platform: pulse_counter
    pin:
      number: 13
      mode:
        input: true
        pulldown: true
    name: "Pulse Counter"
    update_interval: 15s
```

Compilation and transfer to the ESP32 works without any error messages.
Anybody a suggestion for me please?
Thx in advance!
Thomas

Can you provide your wiring diagram?

Haven’t one yet, just measuring the Voltage of GPIO13.
No matter if I pull the GPIO13 up or down in the YAML code, I measure 3.3V against ground.
And the counter doesn’t count if put 3.3V to the GPIO13 (but counts of I connect it to GND).
I was expecting a different behavior:
a) GPIO pulled down => 0V => counting when connected to 3.3V
b) GPIO pulled up => 3.3V => counting when connected to ground

I must obviously be missing something. :man_facepalming:

I have GPIO13 pulled up i.e. external resistor to 3.3v; I get a pulse recorded when the circuit is “made” to ground. I forget whether GPI013 has a pull-up resistor but I tend to use actual resistors as any long runs tend to need some fine tuning on the amount of the pull-up. Try a different pin? I may have missed something.