A method and system are disclosed that collect data from various devices, such as sensors, to a mobile device traveling in proximity to such devices. The mobile device may travel with a user who is traveling a regular-scheduled route. The devices may output a signal at a low frequency to preserve battery power. The mobile device may form an ad hoc connection with the devices using Bluetooth Low Energy, for example, and retrieve the data while the mobile device is in proximity to each of the devices. In this manner, the devices do not need to transmit data over long ranges or at a high speed, thereby preserving batter power for the devices.