Here’s an easy way to transfer data with an infrared LED and an infrared remote control demodulator. The example uses an Arduino, but the technique will work with any microcontroller.

IR-UART

The transmitting microcontroller powers an IR LED from a pin configured as a 38KHz pulse-width modulator. Another pin configured as a 2400bps UART switches the IR LED ground pin on and off. This converts the standard UART output into a train of rapidly-blinking light pulses.

The receiver is an IR remote control demodulator connected to a 2400bps UART input pin. The demodulator is specially tuned to detect IR light pulses at 38KHz. It converts the transmission back into a 2400bps UART bitstream.

How would you use a line of sight data link?

Via Make.

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