I was wondering if it would be possible to wake an ESP8266 from a request over MQTT while it is in Light-Sleep mode? I am planning to implement a smart switch that would receive messages from a Raspberry Pi to turn off and on, however, I don't want to have to manually hit a button to trigger an external reset (I've seen this done in many examples already). I also don't think it would be efficient for me to just set a timer and have the ESP wake up in intervals. For instance, if I want to have the smart switch turn on an appliance and the PI sends a request over MQTT when the ESP is sleeping... this will do me no good. Curious if anyone has run into this issue before and what recommendations you have.
I was wondering if it would be possible to wake an ESP8266 from a request over MQTT while it is in Light-Sleep mode?
No. The ESP8266 has to be awake to communicate with the MQTT server.
The best you can hope for is a periodic wakeup to connect to the server and check for any new data. But of course that relies on the data being set to QOS 2 so it keeps trying to be delivered until the ESP8266 is awake to receive it.