I would like to send a message to an Echo when my child turns on the computer…something like “good morning, did you brush your teeth”. I can detect when the computer turns on or comes out of sleep by seeing if it’s connected to the wifi network…so triggering isn’t a problem…but I’d like to deliver that message only once, not every time he turns on the computer during the day.
You could use a Time condition if he typically only turns it on before a certain time.
Alternately you’d have to create an input boolean. This would need to be reset to zero every night (in a separate automation triggered by time of day), added as a condition to the automation to announce only if it was zero, and as part of the automation itself have it set to 1 when it runs.