Most major cell phone manufacturers have been releasing cell phones equipped with Near Field Communication (NFC). At the same time there is also increasing use of mobile payments and user verification with the use of the NFC technology. These trends indicate both the increasing popularity and great potential for increased use of NFC in today’s society. As a result NFC has a huge potential to simplify our everyday tasks, ranging from paying for items to accessing our office or home. In this context we will focus on using NFC together with a Power over Ethernet (PoE) powered circuit board and NFC reader to realize a simple system for granting access to open a locked door. One of the purposes of this realization is to explore what services can be realized when such a system is connected to the home/building network and connected to the Internet. A second purpose is to learn how to use network attached devices, as the concept of the Internet of Things is considered by many to be a driving force in the next generation Internet. This project uses very in expensive and low power hardware, as the number of devices is potentially very large and thus in order to minimize the technology’s impact on the environment we must consider how to minimize the power used – while maintaining the desired user functionality. This bachelor’s thesis project made it possible for a PoE powered circuit board containing a MSP430 microcontroller to work along with a NFC reader, which was connected through the Serial Peripheral Interface (SPI). We hope that the end result of this project will lead to a simpler life by exploiting this increasingly ubiquitous technology. For example, a homeowner could send a one-time key to a repair person who is coming to fix their sink. Similarly a homeowner could send a key to their neighbor which is valid for two weeks so that their neighbor could come into their home to water the plants while they are away on vacation. Another example is lending your apartment key to a friend while you are out of town. / Det blir allt vanligare med närfältskommunikation (NFC) i dagens samhälle, mobiltelefons-tillverkarna börjar utveckla nya telefoner med NFC teknik inbyggd, samtidigt som användningen av NFC ökat. Det sker även en utveckling inom mobila betalningar och användar-verifiering med användning av NFC, då NFC förenklar detta. Med detta sagt kommer vi att arbeta med detta i detta kandidatexamens-arbete där vi fokuserar på NFC samt Power over Ethernet som använder MSP430 chippet som kärna. Med dessa enheter kombinerade kommer en enkel rörelse med ett NFC kort över en NFC läsare som sedan skall ge åtkomst till en låst dörr. Detta i större kombination med en Internetuppkoppling kunna ge ägaren möjligheten att kunna skicka ut dörrnycklar till andra användare. I detta kandidatexamensarbete gjorde vi det möjligt för ett PoE kretskort bestående av ett MPS430 mikroprocessor att samarbeta med en NFC läsare genom SPI protokollet. Genom att utveckla detta projekt hoppas vi att vårt slutresultat leder till en enklare delning av nycklar med hjälp av denna teknologi.