Development of Wireless Torque Sensing Using Embedded Microchip

In this study, we use two one-port SAW resonators (SAWR) oriented at 45 degree to the shaft to measure the strain of the shaft. When the shaft is applied by torque, the frequency of SAWRs with maximum received signal strength indication (RSSI) will be influenced by the applied torque. Therefore, we measure the shift of the central frequency for the SAWRs and then the values can be used to obtain the applied torque on the shaft. To measure the RSSI signal with respect to the frequency in real-time, a dsPIC33F microchip is developed to control the RF chips (C1100) to achieve the transmitting and receiving task to obtain the frequency shifts. Finally, the torque signal is passed through CAN BUS and UART to integrate with the PC. In the implementation, a microchip based wireless passive torque measurement system is presented.