RSSI based analysis of Bluetooth implementation for intra-car sensor monitoring

This research evaluates the application of Bluetooth for monitoring in-car sensors. Bluetooth technology is chosen to provide reliable communication system with low complexity and production costs. To assess connection among the predefined sensor positions in car, the RSSI (received signal strength indicator) measurement is conducted by using the HC-05 Bluetooth module as the receiver and Android smartphone as the transmitter. The measurement scenario is defined based on the link between master-station at car dashboard to all possible sensor positions. More measurements are also conducted for the coverage of Bluetooth connection in the possible longest distance of car dimensions. The measurement results show that the RSSI receptions from all sensor nodes are higher than the used receiver-sensitivity threshold. Therefore, the implementation of Bluetooth is feasible. However, in the real application, the sensitivity of the implemented Bluetooth module should be carefully considered because the signal reception has possibility to drop below typical threshold in the Bluetooth standard. Therefore, rigorous measurements assuring that all possible sensor placement scenarios should be guaranteed to result in RSSI higher than the threshold of the implemented Bluetooth hardware.