Ancient Web: LIRC Made the PC Serial Port Listen to TV Remotes

Part of the Ancient Web Collection.

Long before every television accessory came with an app, computer hobbyists looked at the infrared remote on the coffee table and wondered whether it could control Linux. Some then soldered together the answer.

Visit Linux Infrared Remote Control.

LIRC is a software project for receiving and sending signals used by infrared remote controls. The surviving site carries a 1999 copyright attribution to Karsten Scheibler and Christoph Bartelmus, and still maintains a design mixing project documentation, mailing lists, driver information, and unusually specific hardware advice.

It explains that the lircd daemon decodes incoming remote signals and makes their commands available to user programs through a socket. A button press could therefore operate a media player, trigger a computer command, or control other hardware.

Build the receiver yourself

The serial-port receiver guide is the kind of page that makes a modern electronics shopper smile. It lists infrared receiver modules by manufacturer, distinguishes carrier frequencies, warns about incompatible pin assignments, and provides a circuit with a diode, capacitor, resistor, voltage regulator, and nine- or twenty-five-pin connector.

Its diagrams include actual ASCII circuit art. Instructions explain how a receiver gets power from the serial port's RTS line, and why the choice of infrared component matters. Readers are warned that some parts may behave badly under fluorescent lighting or have become discontinued.

The homepage also links parallel-port and sound-card designs, older hardware experiments, and a remote-control configuration database. It describes roughly 2,500 supported device configurations at the time of the site's text. That is the project's stated figure, not a fresh inventory of working modern equipment.

The FAQ and HOWTO material keep the software side attached to the circuits. The documentation acknowledges that some newer Linux kernels can recognize certain remotes directly, making LIRC unnecessary in those cases. This is an evolved project retaining its roots, not an application frozen in 1999.

The larger story is an era of personal computing when convenience could begin with identifying an integrated circuit, checking a serial connector's pins, and sharing the schematic with strangers online.

Read the original receiver-building guide.

Part of the Ancient Web Collection.