LED data transmission stable even in >90K lux sunlight is open source and low cost using commercially available hardware

https://www.eurekalert.org/news-releases/1111320

"new 8B13B coding scheme on field-programmable gate array, employing return-to-zero format maintaining balanced number of logical 1 and 0 bits, suppressing visible flicker for stable synchronization... up to 3.48 Mbit/s data rates over approximately 3 m, packet (893 bits) loss rate10^−4 to 10^−5... commercially available: field-programmable gate array, Raspberry Pi, and other electronic parts... autonomous driving (traffic lights/ street lamps transmit data to vehicles)"