"The common blister pack could have an embedded matrix so that the broken foil registers when a pill has been removed. The blister pack would need something like an induction system to communicate with the dispenser that holds it. That seems rather overcomplicated."
Or just print the foil side of the blister pack with the day and dose number. Tablets only ever taken daily are often already printer with three letter day names. Then all yo need is for an app to remind you to take it and cancel the alarm. People with visual or cognitive problems have...erm....problems already so an e-ink label isn't likely to help them much if at all anyway.