Frequency reference controlled by GPS navigation system

Namen moje diplomske naloge je bil izdelati GPS kontroliran frekvenčni standard. Pri izdelavi naprave smo se nanašali na članek Željka Božiča »A GPS controlled frequency standard«. Naprava omogoči, da s cenovno ugodnim kristalnim oscilatorjem pridobimo natančnost, ki jo premorejo dražji oscilatorji. Kristalni oscilator je fazno vklenjen na GPS sprejemnik, ki ima visoko natančen 10 kHz izhod sinhroniziran z univerzalno koordiniranim časom (fr. Temps Universel Coordonné – UTC). Kristalni oscilator je vezan v PLL zanko, s pomočjo katere je krmiljen, da se pridobi visoko natančen 10 MHz signal. Obstajajo naprave, ki omogočajo kvaliteten 10 MHz oscilacijski signal, vendar so cenovno veliko dražje od moje naprave. Naprava vsebuje 10 MHz in 1PPS izhod. Komunikacija z GPS sprejemnikom poteka preko vhoda USB-B, preko komunikacijskega itegreranega vezja FT231. V uvodu diplomske naloge je predstavljeno delovanje GPS sistema, vloga atomske ure in opis GPS sprejemnika Jupiter-T. V drugem poglavju je opisan program EAGLE in izdelava posameznih elementov, ki smo jih dodali v knjižnico EAGLE. V tretjem poglavju je opisana izdelava tiskanega vezja verzije I. in II., delovanje tiskanega vezja in meritev signalov na tiskanem vezju II. V četrtem poglavju je opisana izdelava ohišja, opis indikatorjev in konektorjev na ohišju. V petem poglavju je opisan preizkus naprave. V zaključku so napisane ugotovitve, ki so bile pridobljene med izdelavo diplomske naloge.The object of this thesis, is to construct a GPS controlled frequency standard. When manufacturing the device, we referred to Željko Božič\u27s article »A GPS controlled frequency standard«. The device enables us to gain the same precision by using an affordable crystal oscillator as we would by using a more expensive one. The crystal oscillator is phase locked on the GPS receiver with highly precise 10 kHz output, which is synchronised with Coordinated Universal Time ( French: Temps Universel Coordonné, abbreviated as UTC). The chrysalis oscillator is locked into a PLL loop, and that is how it is controlled to gain a highly precise 10 MHz signal. There are devices, which allow us the quality of 10 MHz oscillating signal, however they are more expensive than my own device. The device contains 10 MHz and 1PPS output. The communication with the GPS receiver is done through the USB-B input, through the FT231 communication chip. The introductory part of the thesis includes a description of the GPS system and how it works, the role of the atomic clock, and the description of the Jupiter-T GPS receiver. The following, second chapter, provides the description of the EAGLE program, and the making of individual elements, which we have added to the EAGLE booklet. The third chapter describes the making of the printed circuit board (PCB) version I. and II., how the PCB works, and the signal measurements of PCB version II. In the next, fourth chapter, the construction of the casing is described, and also the indicators and connectors on the casing. The fifth chapter offers a description of the device testing process. In the conclusion findings are presented, that were discovered whilst writing this thesis

Brushless motor driver designed for standalone photovoltaic system

To diplomsko delo predstavlja načrtovanje in izvedbo samostojnega sistema za pogon brezkrtačnega motorja s pomočjo fotovoltaičnega modula, in sicer gre za pogon obtočne črpalke za kroženje bazenske vode. Običajno so tako imenovani samostojni fotovoltaični sistemi zgrajeni okrog baterijske banke, ki shranjuje viške energije, kadar je le te preveč, in zagotavlja energijo v času, ko sonca ni. Pri kroženju bazenske vode to ni tako bistveno, baterije pa bi pomenile dodatni strošek, težo in volumen sistema, zato je bil eden glavnih ciljev, da se bateriji izognemo. Ker v tem primeru zalogovnika energije ni, je bilo potrebno zagotoviti, da sistem stalno prilagaja moč delovanja zelo dinamičnim trenutnim razmeram osončenja. Sistem ima zato izvedeno sledenje točki maksimalne moči na fotovoltaičnem modulu [1]. S pomočjo pulzno širinske modulacije (PŠM) [2] prilagaja moč črpalke tako, da je le ta v vsakem trenutku enaka trenutni razpoložljivi moči fotovoltaičnega modula. Na mikrokrmilniku, ki nadzira delovanje celotnega sistema, teče operacijski sistem v realnem času, kar omogoča hiter odziv na spremembe razmer in zanesljivo delovanje. Sistem omogoča tudi priključitev drugih 24 V bremen in delovanje motorja s stalno močjo, nekatere parametre vezja pa je moč nastavljati na vgrajenem prikazovalniku LCD, kjer lahko opazujemo tudi trenutne razmere delovanja sistema.This diploma thesis presents the development of a brushless motor controller, powered by a photovoltaic module, incorporating a maximum power point tracking algorithm. This is essentially an off grid photovoltaic system powering a circulation pomp in a home swimming pool. Off grid photovoltaic systems are normally built around a battery bank that serves as a storage for excess energy during high insolation and supplies loads when solar power is not available. This flexibility is not essential to be used in a swimming pool water circulation system. A battery bank would only present additional cost to the system and require more space for the installation, therefore one of the main goals was to design the system that can operate without the battery. Such a system has to be able to control pump power in real time to constantly track the maximum power point on the photovoltaic module. A microcontroller is used to measure the system\u27s parameters and control the motor, and real time operating system provides fast transient response and high system reliability. The system also allows the supply of other 24V loads and includes a constant power mode. An LCD screen is added where basic measured parameters are displayed

CMOS Band-gap reference circuit optimization

Magistrsko delo predstavlja načrtovanje in optimizacijo napetostnega referenčnega vira na osnovi energijske reže v CMOS tehnologiji. Iz simulacij v 0,18 μm in 0,35 μm tehnologiji smo ugotovili, da z uporabo kompenzacije drugega reda dobimo boljši temperaturni koeficient (TK) referenčne napetosti. Referenčna napetost je sestavljena iz napetosti z negativnim temperaturnim koeficientom in pozitivnim temperaturnim koeficientom ter kompenzacijske napetosti. V 0,18 μm tehnologiji referenčna napetost znaša 1,348 V. Simulacije smo izvedli v temperaturnem območju od -40 ◦C do 125 ◦C. TK znaša 9,48 ppm/◦C in rejekcijski faktor napajalne napetosti (PSRR) je -65 dB pri nizkih frekvencah. Vpliv spremembe napajalne napetosti na referenčno napetost znaša 0,25 μV/mV v napetostnem območju od 3 V do 3,6 V. Cilj optimizacije v 0,35 μm tehnologiji je bil dobiti TK boljši od 20 ppm/◦C v temperaturnem območju od -40 ◦C do 150 ◦C. TK je blizu 13 ppm/◦C in PSRR -68,1 dB pri nizkih frekvencah. Vpliv spremembe napajalne napetosti na referenčno napetost znaša 0,40 μV/mV v napetostnem območju od 3 V do 3,6 V. Aktivna površina integriranega vezja znaša 0,073 mm2. Simulacijski rezultati z modeli dveh različnih proizvajalcev v 0,35 μm tehnologiji so pokazali veliko razliko v temperaturnem koeficientu referenčne napetosti. Rezultati meritev izdelanega vezja v 0,35 μm CMOS tehnologiji so pokazali, da se TK in vpliv spremembe napajalne napetosti na referenčno napetost dobro ujemata s simulacijskimi rezultati.The thesis addresses the design optimization of bandgap voltage reference in CMOS technology. The conclusion obtained from computer simulations in 0.18μm and 0.35μm technology is that the second order compensation circuit can improve temperature coefficient (TC) of reference voltage. The bandgap voltage is a sum of a negative TC voltage, a positive TC voltage and a compensation voltage. Simulations based on 0.18μm CMOS technology provide a reference voltage of 1.348V. The TC is 9.48ppm/◦C in temperature range between -40◦C to 125◦C. The power supply rejection ratio (PSRR) is -65dB at low frequencies. The line regulation of voltage reference is 0.25μV/mV with supply voltage variation from 3V to 3.6V. The target of optimization in the 0.35μm techonology was to achieve better than 20ppm/◦C in temperature range between -40 to 150◦C. The resulting temperature coefficient in simulations is close to 13ppm/◦C. The PSRR is -68.1dB at low frequencies. The line regulation of voltage reference is 0.40μV/mV with supply voltage variation from 3V to 3.6 V. The bandgap reference occupies 0.073mm2. A comparison of simulated results between models of two different foundries in 0.35μm technology shows significant differences in reference voltage temperature coefficient. Measurement results of the fabricated integrated ciruit show good complience of the reference voltage TC and line regulation with the simulation results

The development of an iOS application driven mobile robot

This thesis presents the design process and development of a mobile robot and all the necessary software to control it. The goal of the thesis is also to determine, whether a Raspberry Pi computer is a suitable platform to use for robotics related projects. The iOS application provides the ability to guide the robot, watch its video stream and control the angle of its video camera. By using five LED diodes for illumination it is possible to watch the video stream in low light conditions. The mobile application communicates over the network with a program written in Python, that runs on the Raspberry Pi and manages all robot’s functionalities. This work describes the design process of a robot, appropriate hardware and software selection, software development and integration of all needed components into a finished product

Design and implementation of OpenCL kernel in FPGA device

V diplomskem delu smo predstavili zasnovo in izvedbo računskega jedra OpenCL z vezjem FPGA. Uvodoma smo podali problematiko in ključne rešitve za povečevanje zmogljivosti in učinkovitosti procesnih sistemov. Predstavili smo heterogene sisteme, navedli njihov razvoj in izvedbe strojne opreme. Načrtovanje programske opreme za tovrstne sisteme je izredno kompleksno. Rešitev je v ogrodju OpenCL, ki ga je zasnovalo podjetje Apple Inc. in ga prepustilo krovni organizaciji Khronos Group. V delu je predstavljen osnovni koncept ogrodja OpenCL in komponente, ki sestavljajo program napisan za heterogene sisteme. Namen ogrodja OpenCL je splošna uporabnost programa na različni strojni opremi. Za ta namen je podjetje Altera razvilo razvojno okolje Altera SDK za OpenCL, ki smo ga v delu detajlno predstavili. Osredotočili smo se na izvedbo računskega jedra z vezjem FPGA, saj ta predstavlja pomemben del razvoja heterogenih sistemov. Vezja FPGA se vse več pojavljajo v visoko zmogljivih računalniških sistemih HPC in v vgrajenih sistemih, kjer je pomemben dejavnik učinkovitost procesiranja. V primerjalni študiji smo primerjali čas izvajanja funkcije matričnega množenja na računskem jedru OpenCL z vezjem FPGA in z izvajanjem funkcije na splošnem procesorju CPU. Primerjali smo tudi različne izvedbe računskega jedra. Ugotovili smo: (i) da je čas izvajanja funkcije na računskem jedru OpenCL hitrejše za faktor 131 in (ii) da je računsko jedro FPGA-B za faktor 15 hitreje izvršilo funkcijo v primerjavi z FPGA-A.In this thesis we introduce a design and implementation of OpenCL kernel in FPGA. Initially we presented limits of increasing performances of traditional CPU technology. The end of frequency scaling has caused a shift to multicore processing. However, multicore processing has diminishing returns in terms of increasing true application performance due to limits in I/O and memory bandwidth. Heterogeneous computing is a solution to increase performances and efficiencies. However, writing software application for such computing system is a quite challenging. OpenCL is a framework for heterogeneous systems, which was developed by Apple Inc., but is now maintained by the Khronos Group. It allows programs to run on multicore CPUs, GPUs, DSPs and FPGAs. Altera introduced the SDK for OpenCL which convert the OpenCL code to kernels that can be run on an FPGA device. In this thesis we present a user-centric overview of Altera SDK for OpenCL. In the comparison study we take matrix multiplication function and compare the ordinary CPU execution time and the computed kernel time on FPGA. Within the same comparison study we compare computed kernel time of optimized FPGA-B kernel and non-optimized FPGA-A kernel as well. We find out, (i) that same calculation using the OpenCL model provide a speed of 131 times over the ordinary CPU execution and (ii) that only kernel optimization provide a speed of 15 times

Production process of PCB manufacturing

Namen diplomske naloge je predstaviti proizvodni proces opremljanja tiskanega vezja. Tiskana vezja danes srečujemo pravzaprav že v čisto vseh elektronskih napravah. Od njih je odvisno, kako bo naprava delovala. Osredotočili smo se na del strojnega polaganja komponent, imenovan SMT oddelek. V tem delu bo predstavljena izdelava programa za tiskanje spajkalne paste na PCB (Printed Board Circuit), sestava spajkalne paste, optični pregled nanosa paste in glavni del polaganja komponent na tiskano vezje. V proizvodnem procesu je bistvenega pomena tudi taljenje spajkalne paste oz. spajkanje SMT komponent, zato smo tudi to tematiko bolj natančno opisali in predstavili. Spoje na tiskanih vezjih je potrebno skrbno pregledati in morebitne napake odpraviti, preden vezje nadaljuje svojo pot po proizvodnji. Za to skrbi AOI (Automated Optical Inspection) operater. Večina tiskanih vezij je sestavljena z uporabo THT (Through Hole Technology) komponent, ki jih potrebujemo za pravilno delovanje tiskanega vezja. Spajkanje teh komponent se opravlja ročno ali z metodo selektivnega spajkanja. Po končani obdelavi tiskanega vezja sledi pregled in čiščenje vezja pred odhodom v odpremo. Na tem mestu se tiskano vezje ustrezno zapakira, da med transportom ne pride do poškodb.The thesis presents the production process of assembling a circuit board. Circuit boards are nowadays found in almost every electrical device. They determine how a certain device will operate. The main focus of the thesis is on the SMT section. In this part we present everything about the development of the program for solder paste printing on PCB, the structure of the solder paste, optical overview of paste deposit and the main part, assembling components on the PCB. We can say, that the main production process is reflowing of the solder paste or soldering SMT components. That is why we have focused mostly on this topic. Special attention needs to be devoted on the PCB joints, in order to find any production faults which need to be resolved before the board moves to further processing. This work is controlled by the AOI operator. The majority of the PCBs are composed with THT components, which are needed for proper functioning of the board. Soldering of the components is carried either manually or using a selective soldering technique. When the PCB is manufactured, final check and cleaning is performed before dispatching. At this point, the PCB is properly packed, in order to avoid any damage during the transport

Power supply for communication devices in electric energy metering

Magistrsko delo obravnava izdelavo AC/DC pretvornika na podlagi stikalnega napajalnika za uporabo pri komunikacijskih napravah pri merjenju električne energije. V začetku opišemo tipične predstavnike napajalnikov v elektronskih števcih in moţnje topologije AC/DC pretvornika. V nadaljevanju opišemo delovanje zapornega pretvornika z galvansko ločitvijo, ki je nato uporabljen v naši aplikaciji. Osredotočimo se na dimenzioniranje elektronskih komponent, kjer je glavni poudarek na dimenzioniranju transformatorja, saj ta najbolj vpliva na lastnosti zapornega pretvornika. Na kratko se dotaknemo problematike elektromagnetne združljivosti in varnostnega standarda pri načrtovanju pretvornika. Na koncu predstavimo potek razvoja od izračuna komponent do načrtovanja tiskanega vezja in predstavimo rezultate našega dela.The work describes AC/DC converter design for communication devices used in advanced metering infrastructure. At the beginning we describe some typical power supply topologies used in electricity metering devices and possible solutions for our design. Further we describe the topology and priciple of operation of Flyback converter that we use in our application. Focus of our work is the design of electronic components where the main focus is the design of Flyback transformer, due to its large impact on the operation of the converter. We present some electromagnetic compatibility and safety standard issues in designing switchmode power supply. At the end we present development of the converter and the results of our work

A collision prevention safety system for an electric wheelchair

V magistrskem delu je predstavljen razvoj varnostnega sistema za preprečevanje trkov med invalidskim vozičkom in okoliškimi ovirami. Predstavljene so obstoječe rešitve in teoretično ozadje delovanja ter področja uporabe svetlobnih in ultrazvočnih senzorjev za merjenje razdalje. Po opravljeni medsebojni primerjavi senzorjev z vidika natančnosti so izbrani ultrazvočni senzorji, katerih vrednost izmerjene razdalje se je najbolj približala dejanski. Za zagotavljanje fizičnih povezav med zunanjim krmilnim modulom vozička, smernimi tipkami, mikrokrmilnikom Arduino Micro ter že obstoječim krmilnikom, ki omogoča upravljanje vozička z jezikom, je izdelano vezje s pripadajočimi povezovalnimi elementi. Zadnji korak predstavlja razvoj krmilnega algoritma kot rezultat odločitvenih pravil, določenih s tehniko strojnega učenja. Mikrokrmilnik na podlagi izmerjenih razdalj vseh senzorjev določi in hkrati na zaslonu grafično prikaže, v katero smer je premik dovoljen oz. v katero ni.In the master thesis, development of a safety system for the prevention of collisions between electric wheelchair and surrounding obstacles is presented. The existing solutions and theoretical background of the operation and the scope of use of light and ultrasonic sensors for distance measuring are presented. After performing a comparison between the sensors in terms of accuracy, ultrasonic sensors are selected, because their value of the measured distance is the most similar to the actual one. To provide physical connections between the external control module of the wheelchair, arrow keys, the Arduino Micro microcontroller and the existing controller, which allows operating with the tongue, a printed circuit board is developed with the associated connecting cables. A development of the control algorithm as a result of decision rules is determined by the machine learning technique. On the basis of the measured distances from all sensors, the microcontroller determines and simultaneously graphically displays on the screen in which direction the movement is permitted and in which is not