ir port...

Hello All! I would like to install an IR port on my computer (for communicating with my mobile phone)... There is a connector on the motherboard where, according to the manual, Vcc, GND, Rx, Tx are displayed and in the BIOS regarding this, settings for switching UART2 to IR mode. In the price lists for this purpose, only a certain piece of hardware from Asus was found for $20. I don't want to pay $20 for this yet... Maybe someone made a subject? Do you just need a photodiode and an LED and that’s it? Or something else (for example a couple of transistors)? Does your mobile need exactly the same port as the one provided on the motherboard? What should be set in the BIOS? What does this look like programmatically? Does it emulate real Rx/Tx? Or hangs himself on DCD as for Winlirc? Best regards, Evgeniy.