@B3nihana ok i thought it may has problems with es6 in updte process, but chrome should be able to handle es6. can you show your browser console logs

Yeah, I assumed it would be a long shot. I also agree that the refresh flash for something like a clock would be pretty bad, I was thinking that you rarely stare at the mirror information for that long. That also means that using a more power hungry solution with PIR would likely be fine (as long as standby power is low). Thanks for the reply :)