MH-z19 Preheating time

[Brookke]

Describe the problem you have/What new integration you would like

When the MH-Z19 sensor first starts up the first few sensor readings are erroneous and should not be recorded.

Reading the documentation for esphome it states that the setup() method should not block. Therefore what I am proposing is to store the time that the setup method was called and then comparing that to the current time inside the update() method. If it exceeds the threshold then the sensor reading is recorded, otherwise a “sensor is warming up” debug message is added to the logs.

Would this proposal be acceptable?

Please describe your use case for this integration and alternatives you've tried:

N/A

Additional context

Warmup time on other projects has been set to ~2mins