RPi Zero (rpi_gpio) + 8 channel relay: how to configure the default state of relays after a power outage?

Configuration
1

Hello,

I use RPi Zero (rpi_gpio) and a multi channel relay to control some devices. It is configured as follows:

switch:
  - platform: rpi_gpio
    ports:
      17: aquarium_lights
      18: aquarium_oxygen_pump

Everything works nice so far. The only problem I face is the state of the system after a power outage. Right now after a power outage all GPIOs are turned ON after the boot. How can I configure which GPIOs I would like to be ON and which OFF after an power outage reboot? Like in my example above - I would like RPi to turn aquarium_lights OFF and aquarium_oxygen_pump ON by default on each power outage reboot.

Thank you!

2

Use the home assistant start event to trigger an automation that sets the relays how you want.

  trigger:
    platform: homeassistant
    event: start
3

And where/how do I set the relays in the state I want? Can you give an example for the above mentioned GPIOs 17 and 18?

4 
  trigger:
    platform: homeassistant
    event: start
  action:
    service: switch.turn_off
    entity_id: switch.aquarium_lights

The O2 pump is on when home assistant starts so no need to use the switch.turn_on service for that.

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5

Do you have these lights on a schedule?

You can check if you should turn them off using a condition. For example if the lights are normally on between 8am and 6pm:

  trigger:
    platform: homeassistant
    event: start
  condition:
    condition: time
    after: '18:00:00'
    before: '08:00:00'
  action:
    service: switch.turn_off
    entity_id: switch.aquarium_lights

This way the lights won’t turn off if they are supposed to be on.

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6

I actually have several automatons defined for all my relays. Is there such a thing as launch all automations on start event? This way I will not have to mention my conditions twice and I will be able to edit them (once needed) in one place instead of two. Does it make sense?

7

Two ways,

  1. Add this extra trigger to all the automations you want to run on start:
  trigger:
    - platform: homeassistant
      event: start
    - platform: <your existing triggers...>

OR

  1. Add a list of automations to trigger in the start detection automation.
  trigger:
    platform: homeassistant
    event: start
  action:
    service: automation.trigger
    data:
      skip_condition: false
      entity_id: 
        - automation.one_of your_automations_you_want_to_run_on_start
        - automation.and_another
        - automation.and_yet_another
        - etc...

You might want to break up the triggering a bit with delays if there are lots of automations:

  trigger:
    platform: homeassistant
    event: start
  action:
  - service: automation.trigger
    data:
      skip_condition: false
      entity_id: automation.one_of your_automations_you_want_to_run_on_start
  - delay: 1
  - service: automation.trigger
    data:
      skip_condition: false
      entity_id: automation.and_another
  - delay: 1
  - service: automation.trigger
    data:
      skip_condition: false
      entity_id: automation.and_yet_another
  - delay: 1
  - service: automation.trigger
    data:
      skip_condition: false
      entity_id: etc...
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8

If those automations have conditions inside - will the executions of those automations be conditioned or just executed without checking the conditions?

9
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