Technology is described for transferring one or more mobile tags using a light based communication protocol. A mobile device, for example a smart phone, with an image sensor and an illuminator, like a camera flash, initiates transfer of data formatted in a mobile tag displayed by another device by automatically controlling the illuminator to generate sequences of light representing data transfer messages. The other device, for example a user wearable computer device with sensors capturing biometric and health related data, has a photodetector unit for capturing the sequences of light and converting them into digital data. A processor of the other device identifies the data transfer messages and causes a display of one or more mobile tags responsive to the messages. In this way, a number of mobile tags may be used to transfer several kilobytes of biometric data, for example 4-7 KBs, using low power for the wearable device.
