How to build a simple but cool IR (Infra Red) receiver.

[-] Once Lirc is compiled and installed, set the serial port, load the lirc kernel module, and start the lirc daemon (lircd):

setserial /dev/ttySx uart none
depmod -a
modprobe lirc_serial

If everything has gone well, we can test the actual receiving hardware. Take a remote control and start the "xmode2" program (if you don't use X start the character application, "mode2"); press then some buttons on the remote. You should see something like this:

Graphical representation of the IR pulses

Alternatively, if you are using the character version of this program, you should see a list of numbers, spaces, and pulses. What is this all about? It's the graphical representation of the IR pulses, a sort of IR oscilloscope. If you can see the pulses when you press the remote control buttons, you can be sure the hardware is almost basically working. Each button should generate a different "wave" from the others, but always the same if you press it more times.