[dheera]

Hi Valentin, Nice work here. I've played around with a very similar thing in my apartment before, but instead of using visible codes, I thought about various ways to make them invisible to the naked eye. One relatively simple way is using IR LED beacons. Cell phone cameras often pick up near-IR (in fact, the crappier the cell phone, the better). They can continually flash codes that can be read directly by the phone over 30fps video.

The downside is that, being 30fps, your bitrate is heavily limited, thus your address space is limited, but this can be alleviated by geo-localization or combining IR beacons with BLE beacons, either by using BLE beacons to localize, or by synchronizing the BLE beacon broadcast with an IR pulse picked up on camera.

I would love to chat with you more. I'm a recent MIT alum and still in the Boston area.