After some thought I have gone down the road of seeing if I can't use one of those little bluetooth tile like trackers as the timer. They have built in buzzing, lights, batteries and are found for < $5. They also have the added benefit of being able to connect to a phone to allow easier customization on timers, logging , etc. The ultimate goal would be to allow for phone-free control still but give the option to change some settings if desired. Progress will slow a little other projects have picked up. Just wanted to share the thoughts with others.