hi my project for the end of the sem in industrial electronics is a home alarm system. my groupmates and i already have infrared sensors in mind and also the use of magnetic contacts in mind for doors and windows. however my prof does not want the system only to rely on infrared and protection of doors and windows alone. does anyone have ideas on other types of human detecting sensors that i could use to incorporate in the home alarm system? i was also thinking of having a sensor in case of fire as well.