We have developed a system using a combination of a multi-hop sensor network and 3G networks to support patients daily medication in home care. Each medication of a patient is represented by a sequence of close-open-close events of an off-the-shelf pill box, which are detected by a small Hall sensor. The system enables home visiting nurses to remotely monitor their patients' medication and to give feedback on the medication status to patients. This bidirectional communication between medical staff and patients is essential to motivate patients' medication and to make their experience of being taken care for at homes more comfortable. A semi-automatic message generation system helps medical staff to send feedback without spending excessive time and effort. We have been examining this system for more than three months with three subjects and found that a simple open/close sensing of an off-the-shelf pill box can provide a valuable medication history. It has also shown that the feedback system improves the rate of failure medication from 5.3% to 0.0% in the best case.