To be able to evaluate different radio waveforms in a laboratory environment FOI in Linköping has developed an experimental system for radio communication called Rasmus. The system consists of a transmitter, a channel emulator and a receiver. The transmitter modulates a digital signal to a desired analogue waveform. The channel emulator is used to simulate a real radio channel. The channel emulator distorts the signal by splitting it up in several propagation paths.

Softube has developed DSP-card and software for simulation of the sound of old tube amplifiers. The purpose with this thesis is to design a compact amplifier with high power to function together with the DSP-card and build a unit that can replace several other guitar amplifiers. The advantages with that kind of solution could be that it would be cheaper, easier to carry and easier to stor than the real amplifiers. The amplifier that has been designed is of class D type with digital PWM modulator. There is several types of amplifier modules on the market that use analog input signal, but if one of them would be used a D-A converter is needed on the DSP card.

The Anybus CompactCom modules are today using the Anybus NP30 processor. These modules are used for communication between industrial machines and larger network protocols. The communication loads on these systems are increasing every day and the limiting factor for the system is the processor.HMS, the company that develops the Anybus CompactCom, has shown interest for a benchmark test between the old processor and a new processor, ARM Cortex-M3. This project includes that benchmark. To be able to get results that reflect reality a test environment was created to simulate Anybus CompactCom conditions.

Active headsets have been on the market for years and now it is time for something else to enter the stage. The technology of active noise reduction can for exmple also be used in ventilation systems for reducing ventilation noise. An active control system principally consists of four important components, namely the downstream error microphone, the upstream detection or reference microphone, the Digital signal processor (DSP) and a loudspeaker. The upstream reference microphone listen to the primary ventilation noise and sends it to the DSP which makes a phase shift to the signal and sends it to the loudspeaker. The loudspeaker sends out the opposite waveform of the incoming one and reduce the primary ventilation noise.

AbstractThis work was assigned by a technological company that manufactures gas detectors in which the sensor signal is processed using digital filters. These filters have been developed by a consultancy firm which converted previously used analog filters to digital filters. The purpose of this work has been to analyse inadequate, and sometimes erroneous, documentation from the project in order to provide the company with know-how and tools for further improvement of their products. The work has been done using the simulation software COMSOL which was bought solely for the project. Analysis showed serious flaws as well as pure errors in the consultant?s documentation.

Uppgiften var att ta emot och avkoda en radiosignal för tidsangivelse, DCF77. Avkodaren implementerades i en FPGA-krets från ALTERA. Utvecklingen genomfördes i Quartus II-miljön med språket VHDL samt en alternativ lösning där mjuk processor användes. Både utvecklingsmiljön och språken var väl lämpade för uppgiften. Ett genomgående problem var dock radiomottagaren ofta levererade för svag signal för att kunna avkodas korrekt.

Abstract The purpose of this project is to develop a modular processor card which is intended to work as a platform for Kitron Development Karlskoga. The modular processor card is meant to be used as a control system in development projects, mainly in medical and industrial products. The processor card will consist of a central unit with the basic functions for a control system. Furthermore there will be complete modules with machine commodity and programming, to pick exactly the necessary functions for a specific application. With consideration to the specification of the development and the main unit, I chose an adequate microprocessor (AT90CAN32) as core and interface circuits to stated border areas. The construction is first completed in the program MultiSim and then remade in the program OrCAD Capture. The programming language C was used in the software model.

A key part in the development and verification of digital systems is simulation. But hardware simulators are expensive, and software simulation is not fast enough for designs with a large number of gates. As today?s digital zesigns constantly grow in size (number of gates), and that trend shows no signs to end, faster simulators handling millions of gates are needed. We investigate how to create a software gate-level simulator able to simulate a high number of gates fast.

This report deals with RFID systems and how to detect nearby tags with the Mifare standard using only a microcontroller and an antenna circuit.The aim was to investigate whether there was any possibility to continuously search for a nearby tag for a system operated with batteries without compromising   the lifespan of the battery. At this time the system would take too long time to wake up and look for a tag to give a satisfactory battery lifespan, which should be done a couple of times every second.The report has two issues, namely:Is it possible to direct the microprocessor to detect and identify a nearby tag after the Mifare standard?What hardware is required for this to be possible?As the research method to provide answers to the above questions an action research was used. This approach has meant that the group worked on information retrieval, examined existing solutions, tested their own solutions and documented the results.The group examined an existing solution that can search for nearby tags with minimal energy consumption. An antenna circuit was built that was connected to the processor.

Denna rapport kommer att handla om mitt arbete att skapa en digital ecorche och jämföra traditionell och digital skulptering.och möjligheten att kombinera dem..

Syftet med denna undersökning är att ta reda på vad den elektroniska handeln via digital-TV har för förutsättningar att slå sig in på den redan befintliga marknaden där bland annat Internet finns. Elektronisk handel via digital-TV är en tjänst som inte finns idag, men som skall introduceras under hösten 1999.Eftersom handel via digital-TV inte finns i dagsläget, har en jämförelse gjorts mellan digital-TV och Internet för att på så sätt få ett mer konkret resultat vad det gäller digital-TV. Den elektroniska handeln via Internet är på frammarsch och om tekniken fungerar bra på Internet, kan erfarenheterna även utnyttjas och användas på digital-TV.Rapportens resultat visar att den elektroniska handeln via digital-TV kommer att fungera och även att handel via digital-TV kommer att bli ett komplement till Internet. Rapporten visar också vilka produkter och tjänster som kommer att finnas tillgängligt via digital-TV..

Högtalare består idag ofta av flera högtalarelement, avsedda för olika frekvensområden. Signalen som driver dessa måste delas upp genom att oönskade frekvenskomponenter filtreras bort ur respektive utgående signal. Normalt görs detta med passiva komponenter i högtalarlådan. I denna rapport beskrivs arbetet med att ta fram ett digitalt system för att ersätta dessa passiva filter. Teoridelen tar metodiskt läsaren till en relevant kravspecifikation för systemet.

Digital teknik utgör ett obligatoriskt inslag i svensk undervisning, såväl praktiskt som i rådande kursplaner. Följande uppsats behandlar hur digital teknik tillämpas i bildundervisningen på några grund- och gymnasieskolor, samt vad som påverkar tillämpningen. Vidare beskrivs även nårga lärares upplevda relation till anammandet av digital teknik i bildudnervisning..

The purpose with the report is to show that it is possible to design a class-D amplifier, using a programmable FPGA mounted on a developing card from Xess and a H-bridge. The FPGA was programmed in VHDL which is the language the software from Xilinx use to implement a logical function into the FPGA The logical function corresponds to a modeling of the music signal and the modeling can be described as a comparator which compare the music signal with a triangle wave and as a out signal produce a pulse width modulated (PWM) signal. The report is also a review and evaluating of two different modulating technologies, AD- modeling and BD-modeling. A detailed part about how the H-bridge was designed and how it works. The result of this project is a working audio amplifier to a significant lower price than the products in todays market..

This thesis is performed at Saab Bofors Dynamics in Karlskoga and investigates a technique for ranging with laser pulses. The investigated technique is called Constant Fraction Detection (CFD). Described briefly, the received laser pulse is split into two equal parts, where one part is delayed half the pulse width and inverted. This signal is added to the original pulse. The resulting curve has the shape of a laying S and the detection of the zero level is used to stop the time measurement.