Ultrasonic sensor echo_pin on i2c invalid input

meijerwynand commented 3 years ago

Operating environment/Installation (Hass.io/Docker/pip/etc.):

pip

ESP8266 (NodeMCU):

EPS8266 NodeMCU

ESPHome version (latest production, beta, dev branch)

ESPHome v1.15.2

Affected component:

https://esphome.io/components/sensor/ultrasonic.html

Description of problem: When attempting to add an ultrasonic distance sensor on a PCF8574, I am unable to specify the echo_pin as an "i2c" pin. The compiler stops with an error message [pcf8574] is an invalid option for [echo_pin].

Problem-relevant YAML-configuration entries:

...
i2c:
  sda: D2
  scl: D1
  scan: True
  id: bus_a

pcf8574:
  - id: 'pcf8574_hub'
    address: 0x38
    pcf8575: False
...

Expected config to work:

  - platform: ultrasonic
    name: "Ultrasonic Sensor"
    trigger_pin:
      number: 3
      mode: INPUT
      pcf8574: pcf8574_hub
    echo_pin:
      number: 2
      mode: INPUT
      pcf8574: pcf8574_hub

Expected config to work log:

> esphome  i2c.yaml compile
INFO Reading configuration i2c.yaml...
INFO Detected timezone 'SAST' with UTC offset 2
Failed config

sensor.ultrasonic: [source i2c.yaml:49]
  platform: ultrasonic
  name: Ultrasonic Sensor
  trigger_pin:
    number: 3
    mode: INPUT
    pcf8574: pcf8574_hub
  echo_pin:  [source i2c.yaml:56]
    number: 2
    mode: INPUT

    [pcf8574] is an invalid option for [echo_pin]. Please check the indentation.
    pcf8574: pcf8574_hub [source i2c.yaml:58]

Expected config to work note:

The trigger_pin option does not appear to be subjected to this issue / limitation

Additional information and things you've tried:

Alternative test

Here I set the echo_pin to a "normal pin" (non-i2c), keep trigger_pin as an i2c pin and I am able to compile

  - platform: ultrasonic
    name: "Ultrasonic Sensor"
    echo_pin:
      number: 2
      mode: INPUT
    trigger_pin:
      number: 3
      mode: INPUT
      pcf8574: pcf8574_hub

Alternative test log

> esphome  i2c.yaml compile
INFO Reading configuration i2c.yaml...
INFO Detected timezone 'SAST' with UTC offset 2
INFO Generating C++ source...
INFO Compiling app...
INFO Running:  platformio run -d i2c
Processing i2c (board: nodemcuv2; framework: arduino; platform: espressif8266@2.6.2)
...
Building .pioenvs/i2c/firmware.bin
RAM:   [=====     ]  45.5% (used 37296 bytes from 81920 bytes)
Flash: [====      ]  38.5% (used 401732 bytes from 1044464 bytes)
Creating BIN file ".pioenvs/i2c/firmware.bin" using "/home/xxx/.platformio/packages/framework-arduinoespressif8266/bootloaders/eboot/eboot.elf" and ".pioenvs/i2c/firmware.elf"
====== [SUCCESS] Took 9.99 seconds ======
INFO Successfully compiled program.

Observation:

It appears the echo_pin does not honor the Pin Schema as in the documentation.

Thanks

glmnet commented 3 years ago

Well, did not test this but ESPHome measures time between sending a trigger and receiving an echo, while this could be done via a port expansor, getting reliable results will be a nightmare, so I recommend you to not use port expansion pins in this case.

probot-esphome[bot] commented 3 years ago

ultrasonic source ultrasonic issues ultrasonic recent changes _{^{(message by IssueLinks)}}

meijerwynand commented 3 years ago

Well, did not test this but ESPHome measures time between sending a trigger and receiving an echo, while this could be done via a port expansor, getting reliable results will be a nightmare, so I recommend you to not use port expansion pins in this case.

That is what I was testing with, a port expander. The chip is supported as per documentation.

As you mentioned results may not be as reliable, however, for the use case I have in mind should not be an issue. Using a distance sensor to check whether a vehicle is present in the garage. Thus nano second response time is not high on the requirements list.

pctdetail 775-160 1

Thank you for taking the time to look into the issue and giving feedback. It is much appreciated.

ssieb commented 3 years ago

The echo_pin is defined in the config to only accept a gpio pin, not a general pin config. As already mentioned, this is due to the timing requirements and it most likely also uses an interrupt. If your timing requirements are that flexible, you could implement it yourself with a switch: and binary_sensor: using a global variable to measure the time.

stale[bot] commented 3 years ago

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

esphome / issues