I have been working on a few LED and piezo buzzer automations with the Apollo Automation MSR-1 mmWave CO2 Multisensor. The LED turns green on trash night and red if the CO2 levels in our bedroom get too high. I am using the piezo buzzer to alert me when the CO2 levels are dangerously elevated. Let me know what you think and share any LED and piezo ideas/automations you have. I've also added a bonus piezo buzzer song, so be sure to give it a listen! Thanks!