The aim of our diploma work was to create a basis for digital cordless transmission of data over DECT (Digital Enhanced Cordless Telecommunication), which could be expanded in a further project.

The results of our work:

• Three identical input-output-prints (I/O-print), which consist of a complete serial interface, nine switches, a row of eight LED and a serial socket for an additional serial interface. This print was developed and tested by ourselves.
• The DECT transmission unit (MD32, developed by Siemens) and an embedded system (hosting a 167 CPU and our I/O-print) have been mounted on a board. We call this equipment DECT system.
• Routine to set up an active connection between two DECT systems (one has to be configured as a so-called portable part and one as a fixed part).
• Basic routines to transmit and receive data over the serial interface.
• Routines to subscribe and unsubscribe up to 16 DECT systems (portable parts) at a fixed part.
• Routine which enables the fixed part to switch its active connection between the subscribed portable parts.
• Application which uses the described routines above. The positions of the switches are transferred to the remote DECT system and the received data are displayed on the LED row. Typed characters on a PC are submitted via our DECT system to another PC and vice versa.

Current stage of the project:

The hardware has now been developed and might be used as a universal interface for further projects. We provide different routines to establish one active and up to 15 inactive connections. Since we had only three DECT systems, we have tested our application with one fixed part and two portable parts.

The aim of our diploma project was to create a basis for the transmission of data over the isdn-net with the TCP/IP Protocol. This project could be expanded upon at a later stage.

We had to develop hardware and software. The hardware consists of the following components:

• 4 x 40 characters display to display information
• 4 x 4 buttons matrix keyboard to input text and to operate in the menu
• ISDN Modem module
• Mainboard with the TCP/IP Network Protocol Stack
• Microcontroller Siemens C167CR

The software provides the following:

• User interface
• Initialization of the hardware
• Dial-up, send mail, terminate connection
• Scanning of the dynamically assigned IP-address

Current stage of the project:

We provide a data interface on which it is ideal to continue this work on a higher level. Now various Internet-applications can be realized like for example a mail- or a web- server.

The diploma project was very exciting and it was interesting to learn more about the TCP/IP Protocol.

In accordance with the conceptual formulation, a microcontroled board was coupled with a GSM module over a serial interface and finished as an embedded system. We used a standard controller board and a complete GSM module, which is controlled over a serial interface. The communication between the GSM module and the controller board with simultaneous use of the monitor program of the controller board needs two serial interfaces. For a simultaneous data transfer another serial interface is needed. Two of them are available on the standard controller board. The other one was implemented by us using the ports via an UART device and a RS232-Interface converter. The GSM module was arranged together with the serial interface and the communication coupled devices on a european card. The connection between the auxiliary assembly group and the controller board was implemented with the contact strips designed for such projects. The system will be powered with a power supply unit or an accumulator.

The programming of the controller board is done in the high-level language C and can be extended or amended as desired. That not experienced users can make adjustments for in and output units, the allocation for the ports is solved with a simple modifiable table-based file.

For the demonstration of the system a program was developed, which can test and represent all functions easily and descriptive. The program was written in Java and is executable on windows based PC's. All data the GSM module supplies can be represented. For the data link an ISDN-Terminal, or a GSM modem is used with a terminal program like Windows disposes one. In order to analyse the supplied data, a small demo data base was created.

Alternatively the different conditions of the GSM module can also be determined by commercial GSM telephones.

The Universal Serial Bus, USB, will replace the various serial and parallel interfaces for PC peripheral devices in the foreseeable future. Therefore we decided to acquire some knowledge within the area of the USB communication. The project in/output module USB was created.

A PC with Windows 98 and USB link serves as the host of our communication system. The main task of the hardware is the reading of the client data through a serial RS232 interface and the transfer to the host through the USB. The host processes the data and sends it back to the hardware through USB. Then the data is passed on to the second client through the serial RS232 interface.

Due to the different transmission-speeds between USB (12Mbps) and the RS232 interfaces (each 38'400 Baud), it is necessary to buffer the data. Therefore we implemented a buffer administration tool which adjusts the possible transfer fluctuations. The number of the filled buffer is transmitted to the host, so that this can influence the data stream.

Our hardware consists of the Infineon demo board Easy UTAH. This board is equipped with a C161U 16 bits micro controller with USB Interface. The processor is able to produce an output of 18 Mflops with a clock frequency of 36 MHz. In addition, two National Semiconductors 16550 UART were used for the serial RS232 interfaces to the clients.

The application Visual C++ helped us to develop the requested Windows software. Using this development environment we created a graphic user surface to control the communication. The data on the host can be changed for demonstration purpose. The software of the micro controller was implemented with the wedge uVision software in C. In order to test this software we used a remote debugger of pls.

We are convinced having created a well-prepared base for further USB projects.

The goal of this thesis was to develop a system with two embedded systems, connected to communicate either by a CAN-Interface or by a Serial Interface. One embedded system hosts a C167 microcontroller and is responsible for controlling an LC-Display with a Touch-Panel. The other embedded system, a C164 microcontroller, hosts the specific user application software. It was crucial to separate the control of the Touch-Panel from the implemented specific user application software.

Due to the high data transmission rate of the CAN-Interface (1 Mbps) the implemented flow control does not affect the dynamics of the communication.

To reach the highest possible transfer rate in the Serial Interface mode we decided to realize without a flow control in this transfer mode.

As a result of the higher transmission rate as well as the higher security the communication with the CAN-Interface is the transfer mode to be suggested. It is also important to have the opportunity to connect the C167 to a system without a CAN-Interface, such as a 8051-Microcontroller. Therefore we implemented a communication software for the Serial Interface.

With our user application running on the C164 it is possible to show the strengths as well as the weaknesses of the LC-Display used. Because of the small size of the display it is only useful for short text and three or four function keys at most on a single display. Running our application shows a wide range of possibilities for the display from text, to graphics, function keys with different sizes, and even to an animation.

The main problem of our thesis was the communication between the two microcontrollers. The CAN-Interface with its high data transmission rate does not cause any problem.

In the transfer mode with the Serial Interface an application should not have too many graphics on one display, because transfering them to the C167 would lead to noticeable delays.

XEMICS is an internationally semiconductor company, which mainly develops "low cost" and "low power" products in the area of microelectronics. XEMICS gave us two programming and two Socketboards for the XEMICS -Controller XE88LC05, as well as the programming software, which are necessary for the implementation of the program. Our first target was to develop an evaluation board which permits any -Controller to connect over a modem, DECT or LAN to the Internet. The second target consisted of developing a program which can connect over the evaluation board and a modem to the Internet. Thereby a 8-Bit -Controller XE88LC05, supported by a coprocessor S-7600A, is used. The S-7600A takes over the function of the network stack and packs the data, which he receives from the -Controller, in the TCP, IP and PPP frames. The S-7600A also manages all arriving data packages, outgoing data packages and takes over the communication with the modem. We achieved the target of this thesis and are able to present the evaluation board and the program. The 8-bit -Controller can react on an event (keys, sensors...) and establish a connection to the Internet. After this occured an E-Mail is sent with the information on what happened. The -Controller can also receive an E-Mail, analyse its contents and react corresponding the Information in the E-Mail. In the following projects the hardware design is not needed to be changed. The only thing that has to be done, is just to remove a few Jumper (modem, DECT or Ether-net). So further developers can just concentrated themselve on programming the software. This thesis required the knowledge of microcomputer systems and communication networks. Since we only studied control engineering and microcomputer systems, we had to introduce ourselves into communication networks. We are happy to have done this thesis, because we are in the lucky position to have acquired the the knowledge of a new topic.

The company Sulzer Hexis had the patronage to this thesis. This company is developing of a fuel cell, which can be used for generating current and heat production in buildings.

The entire process in such a fuel cell is very complex and needs several regulations as well as control devices. These individual functional blocks of the regulation and monitoring are connected by a bus system of the company Echelon, the Lonworks.

The aim of this thesis was to develop a device which can be attached to the Lon Bus. On the basis of certain network variables this device decides whether a message must be issued by SMS to a service technician. The message is transmitted directly via GSM network or via a similar fixed mains connection. In the latter case, the message is transmitted by a gateway, which passes on the message as an SMS. In the opposite direction the device receives messages and changes certain network variables.

The autocall serves as a base for this system. It should be extended to receive messages. Additionally a binding should be implemented to the Lon Bus System. The following systems were implemented:

ECS1 (Emergency Communication System):Due to input variables pre-defined messages can be transmitted via SMS to a phone number of a technician. He can remote control certain output variables.

ECS2:In contrast to the ECS1 the connection with the ECS2 is a fixed mains connection via a gateway. Subsequently, the message is transmitted with EMI specification. Additionally the possibility of remote controlling the output variables via DTMF tones is offred.

Gateway: The gateway can be operated by Sulzer Hexis and serves as an interface between several systems and the appropriate technicians. The messages received from the individual systems, are passed on on the base of data base entries. Additionally the gateway can receive messages from responsible technicians and passes them with the necessary information on to the appropriate fuel cell system.