Luca Soltoggio made two ESP32 boards communicate using visible light; on each board, a single LED serves as both transmitter and receiver. An Arduino library called SecurePair provides encrypted communication and key exchange. The system relies on the LED’s ability to function as a kind of photodiode. The library is also compatible with ESPNow and LoRa; in typical use, pairing takes place over light, while encrypted data transfer happens over a wireless connection. Although the examples feature two ESP32 boards, more devices can join the system.
Background
LED is not a new name in the FikirPilot archive: we published 2 stories featuring this name in the last 90 days; the most recent one is dated September 20, 2026.