MEASUREMENT OF WIND POWER AND ENERGY USING AN ANEMOMETER WITHOUT MOVING PARTS

The paper deals with the application of a newly developed anemometer without moving parts. It is digitized and has built-in electronics that convert the vibrations of two aluminum fixed frames into two digital signals: one, which shows the strength (speed absolute value)) of the wind, and the other, which shows its direction. Both of these signals are used to calculate wind power and energy. Earlier works have shown that the two-bit stochastic digital measurement method overcomes (eliminates) the problem of the offset of the analog adder. The authors of this paper apply this idea to the digital output of the sensor, where the role of the offset of the analog adder is taken over by the integral nonlinearity of the digital output of the anemometer. The first step in this direction is digitally dithering the sensor output. This principle is presented in detail, as well as a rough estimate of the accuracy gain in measuring wind energy. The obtained result shows that the accuracy in measuring wind energy is not worse than the limit accuracy in the case of a cup anemometer that generates sinusoidal voltage.

Parallel Comparator based voltmeter using Single Electron Tunneling Transistor

By manipulating an electron that tunnels the tunnel junction of a single electron transistor, one will be able to reach a standard output logic “1” or logic “0”. The operation of the Single Electron Transistor (SET) is depending upon the bias voltage as well as the input signal(s). By varying the input voltage levels of a SET, the output voltage levels can significantly be changed on the basis of tunneling of an electron whether tunneling happened or not. As our concentration is the measuring of an unknown voltage, we are to implement a voltmeter system to provide a digital output of 3 bits whenever an unknown input voltage is kept in touching in the input terminal. A reference/standard voltage (say 8mV) will be connected in series with eight resistances ( 8 Rs) for the purpose of making a seven threshold voltages, for 7 comparators, in an ascending order of values from ground to reference voltage for seven comparators which are used in this present work. The voltmeter implemented consists of (i) a voltage divider, (ii) a set of seven comparators, (iii) seven Exclusive-OR gates and (iv) three 4-input OR gates. The concepts of implementing “Parallel Comparator based voltmeter” is discussed in two ways (i) by classical block diagram and (ii) using Single electron transistor based circuit. The measuring of an input analog voltage will not be the same as the digital output value. A 3-bit output indicates that the input analog voltage must lie on within a particular small range of voltage. The encoder circuit which is connected to the outputs of the comparators is hard to construct whenever the three terminals output are expressed with the output variables (Wi) of the comparators. For simple and user-friendly circuit, the outputs (Wi) of the comparators are modified to Di variables so as to get the same 3-bit encoder/voltmeter output. For this purpose, 7 extra component called 2-input XORs based on SET are used. Seven such XORs are set, and the output of them are passed to three 4-input OR gates according to the required logic expressions. It is found that all the output data of the voltmeter are coherently matched with the theoretical aspects. Processing delays are found out for all circuits. Power consumptions of all of them are shown in tabular and graphical forms. All the circuit we are intending to make are provided in due places with their logic circuit or simulation set and the simulation results are provided as well. Different truth tables are given for keeping track of whether input-output relationships matches with the theoretical results. We have thought of whether the present work circuits are faster or slower than the circuits of CMOS based-circuits. The power consumed at the time of tunneling event for a circuit is measured and sensed that it exists in the range between 1×10^(-18) Joules to 22×10^(-18)Joules which is very small amount. All the combinational circuits presented in this work are of SET-based.

IMPLEMENTATION OF LEBESGUE SAMPLING METHOD AND DIGITAL SENSORS FOR CONTROLLING THE LEVEL VARIABLE IN A CONTINUOUS SYSTEM

This study aims to show that the continuous control from a level system can be efficiently measured and controlled using capacitive digital binary sensors, which in this case, replace the measurement signal from an analog differential pressure transmitter in a level control system. The binary sensors low cost and the digital output they process allow the reproduction of a correct signal and the estimation of a variable for controlling the water level inside the process tank through a proportional pneumatic level control valve, which receives the control signal from the Lebesgue sampling estimation algorithm applied herein for processing digital measurements. In this particular case, the Lebesgue algorithm is applied to reproduce the estimation of values obtained from the continuous signal in the real level process for the measurement and control. Also, are compared both, simulated and real outputs obtained using the Lebesgue algorithm and digital sensors, which were applied to a state observer controller that relates digital signals for controlling the real level system output. The application of the Lebesgue algorithm in the real level process concludes that the analog level signal can be efficiently reproduced using this method. In addition, the controller enables the system to smoothly conduct digital output processing using digital sensors to control the system output correctly, validating that not only analog sensors should be applied for controlling the output of proportional actuators, because it is shown that digital binary signals can be used for controlling and emulating continuous signals, which were processed and applied to the pneumatic valve. Keywords: Lebesgue sampling, estimation, binary sensor, observer controller, finite state machine, continuous system, control, LTI systems, identification, state variable, estimated output, proportional actuator

Unjuk Kerja GPIO, PWM, ADC dan Timer pada Mikrokontroler STM32F103, ESP32S dan ATMega328

Perangkat embedded system pada masa sekarang memiliki banyak pilihan terhadap jenis mikrokontroler yang sesuai dengan kebutuhan. Hal ini menjadi tantangan tersendiri bagi pengguna ketika diharuskan untuk memilih salah satu jenis mikrokontroler tersebut. Sebagai contoh permasalahan apakah mikrokontroler yang telah dipilih tersebut memiliki sejumlah pin GPIO yang diinginkan, dengan frekuensi switching yang tinggi, berapakah jumlah kanal, resolusi, linieritas dan durasi konversi ADC, bagaimana kemampuan peripheral internal DAC, Timer dan PWM yang bisa dibangkitkan dari mikrokontroler tersebut. Penelitian ini telah membandingkan setidaknya 4 peripheral internal utama yang dimiliki oleh 3 jenis mikrokontroler. Metode yang dilakukan adalah dengan menguji karakteristik GPIO, PWM, TIMER dan ADC pada 3 jenis mikrokontroler yaitu Arduino ATMega328, STM32F103C8 dan ESP32. Eksperiment dilakukan dengan mengevaluasi frekuensi switching digital ouput, mengevaluasi resolusi sinyal hasil konversi ADC, mengevaluasi ketepatan hasil instruksi delay berkaitan dengan timer program dan waktu konversi sinyal DAC semuanya dilakukan pada masing-masing mikrokontroler. Hasil akhir dari penelitian ini menunjukkan, mikrokontroler ESP32 memiliki unjuk kerja GPIO, PWM, TIMER dan ADC terbaik apabila dibandingkan dengan jenis lainnya. Penelitian ini juga membuktikan integrasi FreeRTOS pada Framework Arduino bisa berfungsi dengan optimal meskipun mikrokontroler berjalan pada 2 task yang berbeda di 2 core CPU yang bekerja secara pararel. Frekuensi switching digital output pada ESP32 mampu mencapai 3MHz, waktu konversi ADC hanya 5,7us dan DAC hanya 3,7us. Today's embedded systems have many choices for the type of microcontroller that suits the needs. This is a challenge in itself for users when required to choose one type of microcontroller. For example, the problem of whether the selected microcontroller has the desired number of GPIO pins, with a high switching frequency, what is the number of channels, resolution, linearity, and duration of the ADC conversion, what is the ability of the internal DAC, Timer and PWM peripherals that can be generated from the microcontroller. This study has compared at least 4 main internal peripherals owned by 3 types of microcontrollers. The method used is to test the characteristics of the GPIO, PWM, TIMER, and ADC on 3 types of microcontrollers, namely Arduino ATMega328, STM32F103C8, and ESP32. The experiment was carried out by evaluating the digital output switching frequency, evaluating the signal resolution of the ADC conversion result, evaluating the accuracy of the delay instruction results related to the program timer and DAC signal conversion time, all of which were carried out on each microcontroller. The final results of this study indicate that the ESP32 microcontroller has the best GPIO, PWM, TIMER, and ADC performance when compared to other types. This research also proves that the FreeRTOS integration on the Arduino Framework can function optimally even though the microcontroller runs on 2 different tasks on 2 CPU cores that work in parallel. The digital output switching frequency on the ESP32 is capable of reaching 3MHz, the ADC conversion time is only 5.7us and the DAC is the only 3.7us.

Smart-band BPM and Temperature Based on Android Using Wi-Fi Communication

Monitoring of patients is an integral part of health-care system, both in the hospital and at home. Monitoring devices are useful to monitor a person's health. Monitoring is necessary in case of symptoms of a disease that must be acted quickly to prevent the patient's condition from worsening. One way of monitoring patients' specifications is shown by their BPM value and temperature. The purpose of this study is the design of devices on a patient's wrist that can monitor BPM and his body temperature in real time and are not affected by distance. This research contribution is a system that can provide bradycardia indicators and tachycardia for BPM while hyperthermia and hypothermia for temperature. For a monitoring device to be more practical and efficient for use, it has a device with real time monitoring and a small frame of bracelets and alerts phones and emails during abnormal conditions. The design of the device uses the SEN0203 sensors as a BPM sensor that has analog and digital outputs, as well as MLX90614 sensors that have a digital output, and then data will be processed and shown live to oled ESP333TTGO and data sent to the blynk application on the phone aided by ESP32TTGO as a wifi module. The BPM has the smallest 0.1% error and the largest of 1.09% whereas the temperature has the smallest 0.19% and the largest of 1.63%. These results can be redeveloped on monitor patients to increase the efficiency of the remote monitoring system with alert conditions of patients at an abnormal time via mobile phones and emails.

Who’s Cheating? Mining Patterns of Collusion from Text and Events in Online Exams

As the COVID-19 pandemic motivated a shift to virtual teaching, exams have increasingly moved online too. Detecting cheating through collusion is not easy when tech-savvy students take online exams at home and on their own devices. Such online at-home exams may tempt students to collude and share materials and answers. However, online exams’ digital output also enables computer-aided detection of collusion patterns. This paper presents two simple data-driven techniques to analyze exam event logs and essay-form answers. Based on examples from exams in social sciences, we show that such analyses can reveal patterns of student collusion. We suggest using these patterns to quantify the degree of collusion. Finally, we summarize a set of lessons learned about designing and analyzing online exams.

Primary calibration of mechanical sensors with digital output for dynamic applications

This article tackles the challenge of the dynamic calibration of modern sensors with integrated data sampling and purely digital output for the measurement of mechanical quantities like acceleration, angular velocity, force, pressure, or torque. Based on the established calibration methods using sine excitation, it describes an extension of the established methods and devices that yields primary calibration results for the magnitude and phase of the complex transfer function. The system is demonstrated with a focus on primary accelerometer calibrations but can easily be transferred to the other mechanical quantities. Furthermore, it is shown that the method can be used to investigate the quality and characteristics of the timing for the internal sampling of such digital output sensors. Thus, it is able to gain crucial information for any subsequent phase-related measurements with such sensors.

Temperature and humidity data acquisition design based on microcontroller ATMEGA8

The need for fast and accurate information is urgently needed to support human performance in various areas, including in the field of meteorology. Information about the weather parameters such as temperature and relative humidity on certain areas need to know quickly and accurately. For example the recording of temperature and humidity of a city, the mountains, or in disaster areas, it will definitely be easier if can be recorded automatically and continuously in a certain time. Therefore it needs a tool that can find out the weather parameters such as temperature and relative humidity on a certain position continuously and automatically. In this case the system can use data acquisition and data logger. System design used in this study consisted of DHT11 temperature and humidity sensor with digital output that is already terkalibrasi, microcontroller ATmega8 as the data processor of the DHT11 and the results will be displayed in the LCD. the display on the LCD always updated every 3 seconds. The results showed that "Temperature And Humidity Data Acquisition Design Based On Microcontroller ATmega8" Media has successfully created according to the specifications of the tool are expected.