Scalable visible light communications with a micro-LED array projector and high-speed smartphone camera

Solid state camera systems are now widely available in portable consumer electronics, providing potential receivers for visible light communications in every device. Typically, data rates with camera receivers are limited by the 60~fps frame rate of both the image sensor and projector systems. Recent developments in high frame rate microdisplays and slow motion cameras for smartphones now permit high-speed, spatially structured signals to be transmitted and captured. Here, we present a method for transmitting data to a smartphone using a CMOS controlled micro-LED projector system. Spatial patterns are projected onto a wall at a refresh rate of 480 Hz, which can be captured by the smartphone's 960 fps camera. Data transfer is performed over meter scale distances, and the use of an alignment frame gives the system a level of tolerance to motion and misalignment. The current system allows data transmission at a peak rate of 122.88 kb/s using a 16 x 16 micro-LED array, which can be readily scaled to Mb/s rates with a higher resolution transmitter.