Perancangan Sensor Kapasitor Dan Penggunaan Sensor Warna Sebagai Pendeteksi Tingkat Kematangan Biji Kopi Kawi Roasting Menggunakan Logika fuzzy Berbasis Arduino

Kopi merupakan salah satu minuman yang sangat di gemari di Indonesia karena rasa dan aromanya. Kopi dalam penyajiannya memiliki jenis berbeda yang ditentukan oleh tingkat kematangan biji kopi saat roasting antara lain light roast, medium roast dan dark roast. Dari ketiga jenis profil roasting tersebut masing-masing memiliki tingkat kadar air dalam biji yang berbeda. Penggunaan mesin roaster untuk menentukan tingkat kematangan biji kopi sering menggunakan pengaturan temperatur dan waktu roasting. Dengan mengetahui nilai kapasitansi dalam menentukan tingkat roasting diharapkan akan menambah keakurasian tingkat roasting. Pada penelitian ini dirancang sebuah sensor kapasitor yang terdiri dari dua keping plat tembaga yang sejajar untuk menentukan tingkat kematangan biji kopi yang telah diroasting.Nilai frekuensi dan sensor warna pada system digunakan untuk menentukan nilai dasar klasifikasi tingkat kematangan biji kopi kawi pada system fuzzy. Berdasarkan hasil penelitian yakni pa da jarak sensor kapasitor sejajar sebesar 2cm pembacaan osiloskop tingkat kematangan dark memliki range frekuensi antara 201 KHz-213 KHz, medium pada range 179 KHz- 206 KHz dan light 178 KHz- 200 KHz. Sedangkan pada pembacaan frequency counter arduino pada tingkat kematangan dark memiliki range 204 KHz- 234 KHz, medium pada range 210 KHz- 227 KHz dan light pada 205 KHz-223 KHz. Hasil klasifikasi jenis tingkat kematangan biji kopi kawi dengan nilai fuzzy untuk dark < 43.50 , 43,50 < medium < 1 74 dan light > 174.

Design of a Linear Voltage to Frequency Converter for Digital Audio Applications

Voltage to frequency converters are used in various types of analog to digital converters in suitable digital audio applications. One of the applications is the Audio Interface which has been considered. The Voltage to frequency converter (VFC) thus plays a major role in the analog to digital conversion. This paper proposes a low power VFC designed in 0.18 µm technology which in turn is used to design a low cost and a high-resolution analog to digital converter (ADC). The analog signal is given to the V-F converter and the VFC output is given to the frequency counter using a suitable link. This counter gives the digital output. The design is implemented in PSoC and the performance is analysed with the previous technologies. Parameters such as sensitivity, output frequency and power consumption are analysed. This V-F converter and ADC are used in the digital audio interface which is used for audio applications. With the proposed VFC and ADC, the interface produced a good SNR compared to the conventional audio interfaces.

Device for Generating and Measuring Time Intervals

The article suggests a device that extends the functionality of the measuring devices such as generators and frequency meters. So these devices can be used as part of working standards in a complex for verification and calibrating stopwatches. The device consists of an electronic commutator and a component controlled by a microcontroller, which forms the required intervals of time and provides a necessary connection from the generator output to the frequency counter input, turned on in the pulse counting mode. The control signal simultaneously arrives at the commutator and the device for automatic start/stop of stopwatches. The circuit design of the device allows minimizing the device’s influence on the overall metrological characteristics of the complex through the use of a high-speed controlled M74HC125 buffer (high-speed CMOS QUAD BUFFER (3-STATE)) as a switch. The M74HC125 buffer in this device is the only metrologically significant node; the state switching time of which in the aspect of this task can be ignored (Fig. 3). A computer and standard software, such as HyperTerminal from the Windows XP or PuTTY distribution, are used to control and communicate with the device. The device can be connected to the computer via USB. For laboratories that have these instruments in operation, this approach can help to avoid acquisitions of the additional reference equipment, which helps to reduce the maintenance and calibration costs of reference equipment.

Effect of a multi-frequency counter-current S-type ultrasound pretreatment on the defatted corn germ protein: enzymatic hydrolysis, ACE inhibitory activity and structural characterization

The effect of low-frequency ultrasound pretreatments on the properties and structure of the defatted corn germ protein (DCGP) are investigated.

Low cost GNSS receivers in time synchronization systems

The GNSS (GNSS — Global Navigation Satellite Systems) receivers can be utilized to obtain accurate time markers. The preliminary results of the cheap GNSS receivers’ tests are presented in the paper. The one receiver’s price (including antenna) does not exceed 30 $. The studies on the use of receivers in the time synchronization systems were executed. Three identical models of receiver modules were used. The 1PPS (1PPS — 1 Pulse Per Second) signals available on the receiver’s output were used. The 1PPS’s main time characteristics were described. Delay times between different receivers 1PPS signals were measured. Measurements were taken using 1 GHz oscilloscope and precise time/frequency counter T3200U. Keywords: time synchronization, 1PPS, GNSS, GPS time