Visible Light Communication enables the interaction between objects using only LEDs.
If devices are going to communicate with one other, more times than not it’s going to be done through Bluetooth or Wi-Fi. However, wireless networks aren’t always available and Bluetooth can drain battery life. Knowing this, a Disney Research team has come up with an alternative way for Internet of Things objects to ‘talk.’ How, you ask? Through LED lights.
Unlike incandescent or fluorescent bulbs, the brightness of LEDs can be controlled with extreme precision. Meaning, they can be turned on and off at very high frequencies that are faster than the human eye can detect. Aside from that, LEDs can even be used as receivers just like photodiodes.
Similar to how two ships passing in the night can communicate via Morse code, a couple of IoT gadgets can now secretly converse through the visible light generated by an LED — a method that the team calls Visible Light Communication, or VLC. Not only can it illuminate a room, but the MCU inside each bulb is capable of transmitting and receiving data.
“VLC creates opportunities for low-cost, safe, and environmentally friendly wireless communication solutions. We focus on connected toys and light bulb networks,” the team writes. “Our work targets a full system design that spans from hardware prototypes to communication protocols, and applications.”
Though the concept of “Li-Fi” has been around for a while, as expected, it would appear that many of VLC’s initial examples are focused primarily on toys. (It is Disney, after all!) Among them included a toy car that can turn on its own lights and come to life when placed near a lamp, as well as a princess dress whose embedded LEDs are activated whenever a wand with its own light comes near.
“LED-to-LED Visible Light Communication allows interaction between toys by only using LEDs. No dedicated hardware is required. When multiple devices are networked with each other, we organize the communication with our software protocols,” the researchers add.
However, the technology has other potential applications as well, with an adapter connected to the headphone jack of a smartphone or tablet to receive signals from overhead lights operating at wavelengths unnoticeable by the human eye. This, for instance, opens the door for LED emitters to be placed around a store to beam notifications to the smartphones of shoppers.
Using a simple mobile app on the device, the lightbulb data can be used to tell a story and visualize both pictures and text. When off, no data is transmitted. When switched back on, the storytelling continues.
As you can see in the photo above, the researchers employed various Arduino Uno boards (ATmega328) as part of the study’s testbed. Read all about the project here.
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