In this work we analyzed the decoding of the TV remote control using a PC sound card. The infrared coded signal is received by an optical sensor and is sent to the line-in channel of the PC sound card, which is used as an analogical-digital converter (A/D) of low cost and high efficiency for low frequency AC signals. A didactic software was used to simulate in the computer a virtual scope, allowing to observe in the PC screen the emitted signal by the remote control and to decode some of its control functions. The construction of the apparatus is easy, very economic, and opening teaching possibilities for high school students and undergraduates.
