The performance of mobile phones and portable computers are increasing day by day. It is not rare, that a multi core processor, few gigabyte of system memory or dedicated graphics core are integrated into one phone. Besides the raw computing power, these devices are also equipped with increasing amount of wireless capabilities and sensors. The phones are able to gather information about their surroundings with their GPS, accelerometer or camera. This data can be easily shared on WiFi networks with other devices, forming a sensor network between them.
The SpyCar project is trying to achieve this kind of sensor network, where a remote controlled car shares its own and collected sensor data with the remote controller. The communicating programs are running on smartphones with Android operating system. My task was to develop two new features for the existing system. I have extended the WiFi network with adhoc mode and developed a new module for NFC.
With the help of NFC, the car can gather location-based informatin from tags placed on the floor. This data is then transmitted back to the remote controller, so the user can receive the message too.
Adhoc mode can be useful, when there are more than two nodes in the network. In normal situations, when the central node of the network moves away from the other clients, then they are unable to communicate until the access point is in range again. In adhoc mode, there is no central node in the network, the clients are able to communicate directly with each other regardless of the state of the node creating the network.