The objective of my thesis was to design the central unit of bus passenger system. Work has been done with cooperation of Silex Intustrial Automatisation Company. They provided the necessary hardware components, and development tools. The aim of this thesis was to create a central unit of GPS based bus passenger information system, which can be controlled manually, or by means of external GPS module. The central unit can communicate with external and internal display boards too.
The bus line database was stored in text files while sound information was stored in MP3 files on SD card. The role of the central unit was to send text and sound information via CAN bus, if the bus reaches the bus stop or door opening/closing event had occurred. The display boards have not been created yet, so initial tests were performed using a development board. The central unit has two operation modes. In the first mode, the bus driver can manually trigger the system to inform the passengers about the next bus stop. In the second mode, the system is capable to inform the passengers according to GPS coordinates without manually interaction. A PC software was created to assign bus stops manually, using GoogleMaps.
The bus passenger information system has simple user interfaces: LCD display, keyboard, and push buttons. High performance 32 bit Fujitsu microcontrollers were used in the central and receiver units, which are designed for automotive applications.
In my thesis, I have examined the available passenger information systems, and collected the advantages and disadvantages and compared these with my system. In the next chapter I introduced the system specification and examined the feasibility of sending sound stream over CAN bus. In the following two chapters, I introduced the hardware and software design. The last part of the thesis I introduced the GPS related program parts.