High-Speed, Real Time Sensor Data Acquisition and Transfer based on the Raspberry Pi Single Board Computer

The Raspberry Pi single board computer is widely used by researchers, hobbyists and professionals as a platform to develop data logging applications and sensor nodes. Nevertheless, there is a considerable lack of effort towards reliable high-speed, data logging implementations. One reason for this is the complexity and missing documentation when employing Direct Memory Access (DMA) channels for the data stream. DMA is necessary for eliminating the significant jitter to the data sampling timing, caused by higher priority task interrupts to the Central Processing Unit. In this paper, we present and validate a high-speed, real time sensor data acquisition and transfer system based on the Raspberry Pi. Data samples are generated by an analog-to-digital converter, which can be used to interface analog sensors. The samples are then stored in the memory with timestamps at sampling rates up to 50 kilo Samples Per Second. Finally, the generated data are transferred to a server using the User Datagram Protocol over Ethernet.