Plug for a gate relay

dan

I am looking to use a plug to open a relay but have through about two failure modes I would like help mitigating. Also are there other risks I need to think about…?

The plug is connected to a transformer that outputs 12V 2A to a mortice strike lock.

Failure scenario 1 is that the plug is disconnected from the home assistant server and doesn’t get a command to switch off (so the gate stays unlocked). Can I have the plug know to switch off after a maximum of, say, 10 seconds?

Failure scenario 2 is the plug starts as “on” after a power cut or if the power goes when it was turned on. I think this is resolved with

substitutions:
   # Aka: `restore_mode` in documentation
   # Options: `RESTORE_DEFAULT_OFF`, `RESTORE_DEFAULT_ON`, `ALWAYS_ON` & `ALWAYS_OFF`
   default_state: "RESTORE_DEFAULT_OFF"".

Thanks for your help, a great community, and a great product!!

MichaelMKKelly

for scenario 1 you could use the “on_client_disconnected” trigger in the api section
so when home assistant disconnects it does something (e.g. unlock) you will probably want home assistant to relock it if it detects that its been unlocked for seemingly no reason (it may not be aware that there was a connection drop). and you can specify the home assistant ip address so it doesnt randomly trigger if you visit the webui for debugging.

I am not 100% sure that connection is active all the time or not but you could maybe trigger something that checks if something is connected. or maybe you could just periodically check if a client is connected or not using “api.connected” my everything presence one flashes an red when its not connected. maybe you could investigate that code and see what they did and “selectively reuse” parts of it. could maybe have a last state variable so it can return to last known state when it reconnects although it might be easier to just have home assistant do that as when its reconnected it will discover the status has changed.

further reading:
https://esphome.io/components/api.html

I hope I have given you some ideas for you to start from.
MK

dan

Thank you RebeccaH; how would i implement that code (I can’t see the example you mention). Is it possible to create a button on the plug that will only power it up for a set amount of time rather than toggle on and off manually.

dan

Got it! Added this to the YAML file:

button:
   # New Switch to Control Relay
  - platform: template
    name: "Unlock gate"
    id: unlock_gate
    icon: "mdi:key-wireless"
    on_press:
      - switch.turn_on: relay
      - delay: 10s
      - switch.turn_off: relay

dan

And thank you, I meant @MichaelMKKelly