Supermarket LED lights talk to smartphone app
French shoppers have become the first to experience a new LED lighting system that sends special offers and location data to their smartphones.
The technology was designed by Philips and has been installed at a famous supermarket in Lille.
It transmits codes via light waves, which are undetectable to the eye but can be picked up by a phone camera.
The innovation offers an alternative to Bluetooth-based "beacons", which are being installed by many retailers.
If users open a compatible app and let their smartphone camera look upwards, this can be used to determine their location - accurate to up to 1m -and the direction they are facing.
It functions in a similar way to GPS-based maps used outdoors, and compares favourably to wi-fi based location systems, which are typically accurate to only 3-5m.