Use of a Raspberry PI single-board computer for image acquisition and transmission

The article presents an analysis of the use of a single-board computer Raspberry PI for video acquisition and transmission. The article focuses on requirements necessary for the recorded image to be used for face analysis to identify facial expressions and microexpressions. The quality of the recorded video frames was verified for different resolutions and fps using PSNR (Peak Signal-to-Noise Ratio). Tests of CPU cores usage were also carried out for simultaneous recording and transmission of different types of video streams. The results show that the size of the effective image area depends on the resolution of recorded video stream. Increasing the frame rate for the given video resolution has a significant impact on the value of PSNR. And the resultant CPU usage, for the available resolutions and frame rates of the video recorded, in most cases does not exceed 15% of the total computing power of the CPU

Algorithms and methods for dual processor control system with precision time counter

W artykule przedstawiono projekt oprogramowania systemu wieloprocesorowego, składającego się z dwóch procesorów programowych Nios II firmy Altera i precyzyjnego licznika czasu o rozdzielczości około 80 ps. Pierwszy procesor odpowiedzialny jest za komunikację systemu przez interfejs Ethernet z aplikacją uruchamianą na komputerze PC. Drugi procesor steruje licznikiem czasu oraz zajmuje się obliczeniami statystycznymi w czasie wykonywania próby pomiarowej. W artykule przedstawiono również opis projektu sprzętowego oraz problem komunikacji pomiędzy procesorami w systemie wieloprocesorowym.This paper presents issues of designing and implementing soft ware for multiprocessor systems. Practical example consists of two soft core processors Nios II from Altera. Developed system is designed for control and data processing of precision timer counter with 80-ps resolution. The first processor runs as a server, providing communication and supervision of the system via the Internet. The second processor controls timer counter and performs statistical computation. Shared memory from FPGA resources is used to interchange data between processors

Dual processor system for precision time counter based on system-on-chip device

W artykule przedstawiono problematykę projektowania systemów wieloprocesorowych jako zintegrowanych systemów cyfrowych (SoC - ang. System-on-Chip). Opisano zaprojektowany system, składający się z dwóch procesorów programowych Nios II firmy Altera i precyzyjnego licznika czasu o rozdzielczości około 80 ps. Pierwszy procesor odpowiedzialny jest za komunikację systemu przez interfejs Ethernet z aplikacją uruchamianą na komputerze PC. Drugi procesor steruje licznikiem czasu oraz zajmuje się obliczeniami statystycznymi w czasie wykonywania próby pomiarowej. Wymiana danych pomiędzy procesorami realizowana jest za pomocą pamięci współdzielonej.This paper presents issues of designing and implementing FPGA-based multiprocessor systems. Practical example consists of two softcore processors Nios II from Altera. Developed system is designed for control and data processing of precision timer counter with 80 ps resolution. The first processor runs as server, providing communication and supervision of the system via Internet. The second processor controls timer counter and performs statistical computation. Shared memory from FPGA resources is used to interchange data between processors

Low-cost MEMS sensors for inertial navigation systems

W artykule zaprezentowano system pozycjonowania zbudowany przy użyciu sensorów nawigacji inercyjnej (INS) oraz odbiornika GPS. Jako czujniki inercyjne zastosowano niskokosztowe, powszechnie dostępne akcelerometry i żyroskopy wykonane w technologii MEMS. Omówiono sposób kalibracji akcelerometru oraz metody przetwarzania sygnałów z sensorów MEMS. Przedstawiono również wyniki przeprowadzonych badań eksperymentalnych.The paper presents a positioning system with GPS and inertial sensors. The system is based on commercial solutions described in [1, 3]. The designed system consists of a GPS receiver, a MEMS accelerometer, a MEMS gyroscope, an electronic compass and a pressure sensor. Data processing was carried out by use of a microcontroller with ARM Cortex-M3 core. Designated positions are recorded on a microSD memory card and transmitted by the UART interface according to the NMEA standard. The experimental tests consisting in driving on city roads were performed. The measurement results were recorded directly from the GPS receiver and the system output. Characteristic places such as a tunnel or railway traction were analysed. The results obtained show that MEMS sensors improve the accuracy of determining the position during short-term GPS signal outages. They allow setting the positions more accurately in difficult terrain such as dense urban areas and underground tunnels. In addition, application of low-cost sensors gives a possibility to use the system in popular car navigation systems or mobile phones

A Low-Power Autonomous Sensor Module for Biomedical Applications

The paper presents the construction of an energy-efficient, stand-alone measurement module, designed for use in biomedical applications. The paper discusses the use of an algorithm implementing the acquisition and processing of data, whose main objective was to minimize energy consumption. For the construction of the measuring module, there are used a microcontroller with Cortex-M4F core and two external digital sensor systems: (1) analog-front-end circuit, designed to measure the ECG signal, and (2) a 3-axis system of an integrated accelerometer, gyroscope and magnetometer, made in MEMS technology. In order to minimize the energy consumption, the solutions proposed include dynamic frequency management, the introduction of sleep modes, and the use of selected hardware features of the microcontroller. The proposed techniques and algorithms are implemented to measure the ECG signal at a sampling rate of 250 Hz. Experimental studies of the sensor module constructed were carried out. As a result of the energy saving techniques used, the working time of the device was extended by more than 6 times

A method for testing the performance of a dual-core microcontroller with integrated program and data memory

The paper presents a set of test procedures for performing an extended test of dual-core microcontroller performance. The procedures described enable the performance of the system to be determined with regard to memory organization, mutual influence of cores and ability to verify the impact of code optimization level. The experimental trials were performed using an LPC4357 microcontroller with onboard FLASH and SRAM memory. The results obtained showed a slight performance drop for the various microcontrollers operating simultaneously in typical conditions. However, with frequent references to a shared memory, the performance drop may reach as much as 80%

Real-time data acquisition based on common use interfaces at Matlab and embedded system

The article presents the tests of method for real-time data acquisition from embedded systems using Matlab software. Data transmission is performed using several common use interfaces: UART/USB, Ethernet, Bluetooth and WiFi. The article includes a description of a protocol, measuring station based on two types of embedded system, implementing the proposed protocol, as well as a description of the algorithm of test programs. Experimental studies were performed using a STM32F4 microcontroller and Raspberry PI-3 single-board computer. Executed tests related: (1) the average transmission time, (2) the effective throughput of a full cycle of data exchange, (3), the required working time of Matlab to handle the transmission, and (4) the stability of the program timer used for periodic data transmission calls. Experimental studies have shown that it is possible efficient data exchange between the embedded system and Matlab while maintaining the real-time requirements

Heart rate measurement using EMFi sensors

W artykule przedstawiono sposób użycia elektromechanicznej folii EMFi do pomiaru częstości skurczów serca człowieka. Stanowisko pomiarowe składa się z dwóch sensorów EMFi, umieszczonych na typowym krześle biurowym, modułu referencyjnego do pomiaru EKG i SpO2 oraz karty DAQ. Wyznaczono wartość tętna dla sygnału EMFi i EKG. Błąd pomiaru tego parametru określony z serii pomiarów wykonanych w czasie 1 minuty i szacowany jako różnica między sygnałem pochodzącym z EMFi a sygnałem EKG wynosi < 1 %.The Electro-Mechanical Film (EMFi) sensor for measurement of the human heart rate is presented. EMFi material is used to non-invasive technique for the assessment of the cardiac function called ballistocardiography (BCG). Construction and sensor operation are shown in Fig. 2. There was built a measurement setup from a typical office chair with ECG and SpO2 reference module (Fig. 4) for obtaining the ballistocardiogram . The EMFi signals from a subject sitting on the chair are recorded by a specially-designed amplifiers, analog filters and dedicated data acquisition card. A Matlab PC software was used for recording, data processing and displaying the results. EMFi sensors were mounted on the chair seat and backrest. The example signals are shown in Figs. 5, 6. The authors' method was evaluated by comparing the beat-to-beat heart rate (HRBB) values obtained from the EMFi sensors with the accurate reference values calculated from the reference ECG signal. The experimental results (calculated heart rate) are presented in Figs. 9, 10. The measurement error for the HRBB parameter, estimated as a difference between the EMFi and reference signal, is below 1 %, during 60-second recording

Evaluation of performance of processors embedded in FPGAs systems

W artykule przedstawiono ocenę wydajności sprzętowego (PowerPC) i programowego (MicroBlaze) procesora, wbudowanego w układ FPGA typu Virtex-4 firmy Xilinx. Uzyskane miary wydajności zestawiono z wynikami uzyskanymi dla procesorów autonomicznych typu ARM i DSP. Opisane szczegółowe porównanie procesorów wbudowanych w układ FPGA może pomóc projektantowi w wyborze sprzętowego lub programowego procesora dla różnych aplikacji oraz daje ogólną ich ocenę w porównaniu z procesorami autonomicznymi. Badania wydajności przeprowadzono na dwa sposoby: pierwszy dotyczył testów dla jednakowej częstotliwości pracy zegara (100 MHz) i różnych konfiguracji pamięci, natomiast drugi przeprowadzono dla częstotliwości maksymalnych.This paper describes a simple, yet effective and convenient method for evaluation of the computing performance of hard- and soft-processor (PowerPC and Micro-Blaze, respectively) embedded in Virtex-4 FPGA from Xilinx. Experimental results have been compared with standalone ARM and DSP microprocessors. Detailed comparison of the performance of both processors is presented to help designers to choose between the hard- and soft-processor in different applications. This comparison has been performed in twofold way: the PowerPC and Micro-Blaze cores have been tested at the same clock frequency (100 MHz) for some available configurations of the memory subsystem, and maximum performance factors of both cores have been measured using maximum clock speed

Zintegrowany system monitorowania stanu psychofizycznego kierujących pojazdami

The article presents a system designed for training and researching driver behaviour to improve road safety as well as to identify and eliminate potentially dangerous situations. The testing station has been equipped with a truck cabin, indicators, sensors for testing the driver’s behaviour, and the necessary software. It is expected that research conducted in a strictly controlled environment will enable understanding the impact of the factors associated with driving (driving time, microclimate, noise, vibration, fatigue, stress), as well as other associated factors, such as pharmaceuticals, drugs, alcohol, etc. Understanding the impact of individual factors and their various configurations will enable developing methods to prevent negative effects of these factors, thus minimizing the risks in traffic.W artykule przedstawiono zaprojektowany system do badania zachowań kierowców i poprawy bezpieczeństwa ruchu drogowego, jak również do określenia i wyeliminowania potencjalnie niebezpiecznych sytuacji na drodze. Zbudowane stanowisko laboratoryjne wyposażono w kabinę ciężarówki, wskaźniki i czujniki do badania zachowania kierowcy oraz wytworzono oprogramowanie. Oczekuje się, że badania prowadzone w kontrolowanym środowisku pozwolą zrozumieć wpływ czynników (czas jazdy, mikroklimat, hałas, drgania, zmęczenie, stres, jak również leki, narkotyki, alkohol itp.) na sposób kierowania pojazdem. Zrozumienie wpływu poszczególnych czynników pozwoli opracować metodę zapobiegania negatywnym skutkom stosowania tych czynników