Abstract: A marking detection system detects markings on a printed medium, such as pencil markings in bubbles on the printed medium. The marking detection system includes a circuit board with a plurality of components thereon, including an optical subsystem and an electronic subsystem including circuitry. The marking detection system further includes a shroud for optically isolating a plurality of emitting and detecting elements of the system.

Abstract: A wireless classroom response system includes multiple wireless networks, each serving a different classroom. Each network has a computer located proximate to the classroom that the wireless network serves. The computer executes a communications server and an application program, wherein the application program facilitates classroom activities. The system also includes a wireless access point located proximate to the classroom. The wireless access point is communicatively linked to the computer. The system also has a plurality of handheld units. Each handheld unit displays, to a user, a list of the networks, and receives a user input indicating which one of the wireless networks the handheld unit should connect. The handheld unit connects to the chosen wireless network, thereby becoming a node in the wireless network. It also transmits data to the application program via the wireless access point and the communications server.