Android-based oscilloscopes have been developed for research and educational purposes because they are able to acquire, transmit, display, and analyze any electrical signals since they are mobile and easy to operate.
Due to the speed limitation of wireless transmission channels, android oscilloscopes have some limited performances on several aspects such as bandwidth, waveform capturing rate (WCR), etc.
Kim Mun Hyok, a section head at the Faculty of Automation Engineering, has proposed a real-time lossless data compression scheme to solve a bottleneck of continuous data flow from a data acquisition device (DAQ) to a smartphone. This scheme consists of triggering a signal and encoding differences between waveforms (DBWs).
He also proposed an advanced structure of android bluetooth oscilloscope (ABO) to implement the proposed compression algorithm with field programmable gate array (FPGA)-based hardware and software.
To evaluate WCR improvement, he first analyzed relationship between WCR and compression ratio, and then, verified the compression efficiency by MATLAB simulations using various waveforms, such as simple sinusoidal, complex periodic, square, and chirp waveforms.
He finally studied the robustness of this instrument within the range of 0–15% noise amplitude and 0–2rad phase offset. All the experimental results showed that the proposed scheme can enhance WCR and at the same time it can also be applied to the wireless transmission fields collecting and displaying electrical waveforms.
If further information is needed, please refer to his paper “A Triggering-and-Encoding Lossless Compression Scheme for Waveform Capturing Rate Enhancement of Android Bluetooth Oscilloscope” in “IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT” (SCI).
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