For our Senior Project, we designed, built, and programmed a system capable of counting occupants in a room.
To this end, we used an MSP430 microcontroller to interface with a solid-state relay, two sets of both IR receivers and IR LEDs, and a PIR motion sensor to count the number of people entering and exiting a room. I made the initial design of the project, created a general materials list, programmed the microcontroller logic, and interfaced all the sensors and components. James, my project partner, made a specific materials list, purchased all materials, designed and built the test rig (including the components and actual doorway), designed a circuit board intended to integrate all the components, helped hash out the microcontroller logic, and made the report.
Some challenges included learning how all these sensors worked because we had never used them before, deciding on a logic flow for all of the sensors to follow, and placing the sensors to accurately count ingress and egress.
By the end of the course, the system was complete and it successfully turned on and off lights depending on a series of logical conditions to determine whether the room was occupied.