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FM Transmitter of APRS Telemetry in 144 MHz Band
Bohátka, Jan ; Šádek, Václav (referee) ; Urbanec, Tomáš (advisor)
APRS system is described are sent toin my essay, which is used for sending and receiving text messages. The text messages frequenc 144 MHz by using the modulation scheme AFSK. APRS communicate by using the protocol AX 25, which sends and receives the text messages in the area where are carried despatches and control bits as well. The whole area of high frequency part is in one integrated circuit. The control, coding and decoding of the area is the microcontroller’s job.
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FM Transmitter of APRS Telemetry in 144MHz Band
Bohátka, Jan ; Šádek, Václav (referee) ; Urbanec, Tomáš (advisor)
APRS system is described are sent toin my essay, which is used for sending and receiving text messages. The text messages frequenc 144 MHz by using the modulation scheme AFSK. APRS communicate by using the protocol AX 25, which sends and receives the text messages in the area where are carried despatches and control bits as well. The whole area of high frequency part is in one integrated circuit. The control, coding and decoding of the area is the microcontroller’s job.
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Precise universal timer
Bohátka, Jan ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
Nowadays the precision of the time is highly required. Often not even the user is aware of the possibility to use different services thanks to the fact that the time is synchronized by some means. There is a plenty of possibilities how to keep exact time: through the use of atomic clock, by synchronization through the internet, radio after as much as the GSM, DCF. The signal DCF77 that is available in a great part of Europe is precise enough for most of the common goods and services. The signal is broadcasted from long-wave sender in Germany located not far from Frankfurt. In the thesis I described possibilities of the DCF signal reception and proposed the device able to decode the signal. For the usage and the configuration of the device a PC is required, after the configuration the device is able to work without a connection to the PC. Module enables to switch on and off four uniphase devices into tension 230V and electric current 10A. The most important part is microcontroller Atmega8 that decodes an signal, switches off and on the loads and operates the clock. Atmega8 does not contain USB port so for a comfortable communication it was necessary to complete the module by a converter RS232 USB. Software of the microcontroller is programmed in C-language and the AVR Studia environment. Application control is designed in C#-language and the Visual Studio 2005 Professional environment.
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FM Transmitter of APRS Telemetry in 144MHz Band
Bohátka, Jan ; Šádek, Václav (referee) ; Urbanec, Tomáš (advisor)
APRS system is described are sent toin my essay, which is used for sending and receiving text messages. The text messages frequenc 144 MHz by using the modulation scheme AFSK. APRS communicate by using the protocol AX 25, which sends and receives the text messages in the area where are carried despatches and control bits as well. The whole area of high frequency part is in one integrated circuit. The control, coding and decoding of the area is the microcontroller’s job.
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Precise universal timer
Bohátka, Jan ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
Nowadays the precision of the time is highly required. Often not even the user is aware of the possibility to use different services thanks to the fact that the time is synchronized by some means. There is a plenty of possibilities how to keep exact time: through the use of atomic clock, by synchronization through the internet, radio after as much as the GSM, DCF. The signal DCF77 that is available in a great part of Europe is precise enough for most of the common goods and services. The signal is broadcasted from long-wave sender in Germany located not far from Frankfurt. In the thesis I described possibilities of the DCF signal reception and proposed the device able to decode the signal. For the usage and the configuration of the device a PC is required, after the configuration the device is able to work without a connection to the PC. Module enables to switch on and off four uniphase devices into tension 230V and electric current 10A. The most important part is microcontroller Atmega8 that decodes an signal, switches off and on the loads and operates the clock. Atmega8 does not contain USB port so for a comfortable communication it was necessary to complete the module by a converter RS232 USB. Software of the microcontroller is programmed in C-language and the AVR Studia environment. Application control is designed in C#-language and the Visual Studio 2005 Professional environment.
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FM Transmitter of APRS Telemetry in 144 MHz Band
Bohátka, Jan ; Šádek, Václav (referee) ; Urbanec, Tomáš (advisor)
APRS system is described are sent toin my essay, which is used for sending and receiving text messages. The text messages frequenc 144 MHz by using the modulation scheme AFSK. APRS communicate by using the protocol AX 25, which sends and receives the text messages in the area where are carried despatches and control bits as well. The whole area of high frequency part is in one integrated circuit. The control, coding and decoding of the area is the microcontroller’s job.
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