Abstract:
A connection apparatus and a portable system thereof are connected to a traffic message channel (TMC) device through a universal serial bus (USB) port. The portable system includes a satellite navigation device for performing a positioning function through the global positioning system and displaying a traffic message through a display interface, a USB port connecting to the TMC device to transmit the traffic message to the satellite navigation device, and a switch device for determining whether the connecting device is a USB device or a TMC device and switching the transmission standard and power supply mode thereof.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 09410318 filed in Taiwan, R.O.C. on Mar. 2, 2005, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a connection apparatus and particularly to a connection apparatus and a portable system (such as a satellite navigation device) adopted in the connection apparatus that are used in wireless navigation systems to enable a traffic message channel (TMC) device, to be linked to the satellite navigation device through a universal serial bus (USB). 
     2. Related Art 
     Development of the information society has created a higher demand for traffic information. To establish a comprehensive traffic information announcement system is the main content of an intelligent traffic system. This is a traffic information service, heavily focused on city traffic management in many countries. 
     In most cities and metropolitan areas of many countries traffic broadcasting radio stations have been set up. Before the advanced vehicle-based navigation devices are widely available, the traffic broadcasting radio station is the main channel for announcing instant and dynamic traffic information. Most foreign traffic information broadcastings adopt the radio digital system (RDS) developed by the European Broadcasting Union (EBU). The present RDS has been converged with the TMC to form RDS-TMC. According to statistics, information utilization that adopts the RDS-TMC has increased from 39% of the regular traffic broadcasting system to 64%, travel time can reduce 3%-9%, and driving speed can increase 30%. In recent years, with the advance of traffic broadcasting technology, the broadcasting method has switched from analog to digital. With the new generation of handheld satellite navigation devices coupled with the TMC system, users have even better control of traffic conditions. 
     However, problems still exist for coupling the USB 1.1 interface with the TMC device and satellite navigation device. For instance, power supply is one of the problems. As the general satellite navigation device is connected to other electronic devices (such as computers) through the USB interface, the voltage required for the satellite navigation device is provided from the computer. On the other hand, when coupling with the TMC device, the voltage required for the TMC device has to be provided by the satellite navigation device. 
     Hence how to smoothly connect the TMC device to the satellite navigation system through the USB is an issue remained to be resolved in the industry. 
     SUMMARY OF THE INVENTION 
     In view of the disadvantages and problems not yet resolved in the prior art, the present invention aims to provide a connection apparatus and a portable system thereof that can connect a USB communication port to a TMC device. The TMC device can receive radio frequency to transmit traffic messages to the TMC device. 
     The connection apparatus according to the invention includes a USB port and a switch device. 
     The USB port is connected to a TMC device to transmit traffic information. The switch device determines whether the connecting device is a USB device or a TMC device, and switches the transmission method and power supply mode. 
     In addition, the invention also provides a portable system that includes a satellite navigation device to perform positioning through a global positioning system (GPS) and display traffic information through a display interface, a USB port connecting to the TMC device to transmit the traffic information to the satellite navigation device, and a switch device to determine whether the connecting device is a USB device or a TMC device, and switch the transmission standard (e.g. USB 1.1 or USB2.0) and power supply mode. 
     By means of the switch device, the TMC device can be connected to the satellite navigation device through the USB. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given in the illustration below only, and thus does not limit the present invention, wherein: 
         FIG. 1  is a system block diagram of a satellite navigation device and a TMC device according to the invention; 
         FIG. 2A  is a circuit diagram of the connection system of the invention; 
         FIG. 2B  is a transformation circuit diagram between the TMC device and the USB device of the invention; 
         FIG. 3A  is a circuit diagram of power supply switch according to the invention; 
         FIG. 3B  is a circuit diagram of USB power supply according to the invention; 
         FIG. 3C  is a circuit diagram of TMC power supply according to the invention; and 
         FIG. 4  is a system flowchart of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Refer to  FIG. 1  for a system block diagram of a satellite navigation device and a TMC device according to the invention. The satellite navigation device  200  includes a USB port  210 , a switch device  220 , a central processing unit (CPU)  230  and a display interface  240 . The TMC device  100  is connected to the satellite navigation device  200  through a USB interface  150 . 
     The TMC device  100  receives traffic information by radio transmission through a radio digital system (RDS). When a remote traffic incident occurs, the information of the traffic incident is transmitted to a traffic information center (TIC); then the incident information is sent to the TMC device  100  through an FM bandwidth via a radio broadcasting station. When the TMC device  100  receives the incident information, the signal is transmitted to the satellite navigation device  200  through the USB interface  150 . 
     The satellite navigation device  200  may be a handheld satellite navigation device, or a built-in or externally connected smart phone or personal digital assistant (PDA). The satellite navigation device  200  has the CPU  230  to process various signals, such as sound, images, control signals, and the like. The satellite navigation device  200  generally includes a GPS module, which transmits data (TX and RX) with the CPU  230  through a universal asynchronous receiver transmitter (UART) (not shown in the drawings), which serves as an interface. 
     The satellite navigation device  200  of the invention further has a USB port  210  to connect to instruments (such as computers) that are equipped with a USB interface  150 . After connection, data stored in the hard disk of the satellite navigation device  200  can be moved to input and output. Of course, if the USB port  210  is connected to the TMC device  100 , the signal of the TMC device  100  can be transmitted to the satellite navigation device  200 . After having been processed and analyzed through software, the location of the traffic incident can be indicated on the display device  240 . 
     As the satellite navigation device  200  and TMC device  100  have respectively an independent power supply, the general satellite navigation device  200  connected to the USB is a client with a voltage provided by an external system. But if it is connected to the TMC device  100 , the satellite navigation device  200  has to be provided with a switch device  200  to switch between the general USB device and the TMC device  100 . Details of data transmission and power supply are elaborated as follows: 
     For data transmission, refer to  FIG. 2A  for the circuit diagram of the connection system of the invention. A connector  300  is provided to receive signals from a USB device or TMC device through a circuit. The connector  300  may adopt a product of model No. UH51543-S7 produced by FOXCONN corporation. The USB device and TMC device  100  transmit data through contacts RX_USBN− and TX_USBP+ through the connector  300 , and contacts USB 1 _N− and USB 1 _P+ that are linked to the CPU  230  of the satellite navigation device  200 , the traffic incident information is received for processing and analyzing. 
     Refer to  FIG. 2B  for a transformation circuit diagram between the TMC device and USB device of the invention. In the circuit diagram there are a first analog switch multiplexer  311  and a second analog switch multiplexer  312 . The analog switch multiplexers may adopt analog switch multiplexers model No. NC7SB315 produced by Fairchild corporation. Take NC7SB3157 as the first analog switch multiplexer  311  as an example, it has six contacts. Contact VCC is the power supply end. Contact GND is grounded. Contact A is connected to the contact RX_USBN− shown in  FIG. 2A . Contact B 1  receives signals of the USB device. Contact S is connected to a determination level USB/TMC#. Contact B 0  aims to transmit data from the TMC device  100 . Take NC7SB3157 as the second analog switch multiplexer  312 , which also has six contacts. Contact VCC is the power supply end. Contact GND is grounded. Contact A is connected to the contact RX_USBP− shown in  FIG. 2A . Contact B 1  aims to transmit signals of the USB device. Contact S is connected to a determination level USB/TMC#. Contact B 0  aims to transmit data from the TMC device. Signal switching is based on the determination level USB/TMC#. If the determination level USB/TMC# is 1, it means that the TMC device  100  is connected, then the contacts A and B 0  of the first analog switch multiplexer  311  are connected, and the contacts A and B 0  of the second analog switch multiplexer  312  are connected, then the signals of the TMC device  100  can be transmitted according to the serial communication protocol. 
     For power supply, refer to  FIG. 3A  for the power supply switch circuit diagram, which shows a switch device. It includes a high-speed switch device  329  and an inverter  328 . The high-speed device  329  may adopt a high-speed switch device, model No. IRLML6402, produced by an International Rectifier corporation. The inverter  328  may adopt an inverter model, No. 3LN01M, produced by SANYO corporation. The high-speed switch device  329  and the inverter  328  are connected through a node C. The high speed switch device  329  has a node B connecting to a determination level TMC_ON of the TMC device. The inverter  328  has a node D connecting to a contact USB_VBUS shown in  FIG. 2A . When the determination level TMC_ON is 1 in the system, it means that the TMC device  100  is connected, and the inverter  328  is activated. The power supply is connected to the high-speed switch device  329 , and provides electric power to the TMC device  100  from the satellite navigation device  200  through the contact USB_VBUS. 
     By contrast, referring to  FIG. 3B  for the USB power supply circuit diagram, if a general USB device is connected, one end of the circuit is connected to the contact USB_VBUS shown in  FIG. 2A , another end is the determination level USB_CABLE_DET of the USB device. If the level of the USB_CABLE_DET is 1, it means that the USB device is connected. Therefore through a voltage dividing circuit, the satellite navigation device  200  can get the voltage through the connected USB device. 
     Refer to  FIG. 3C  for the TMC power supply circuit diagram. The external power supply of the TMC device is connected to a node B shown in  FIG. 3A  through a power transformation chip  330  which is model No. AAT3110IGH-5-T1, and a determination level TMC_ON output by a contact SHDN. If the TMC device  100  is connected to the satellite navigation device  200 , the output level of the determination level TMC_ON is 1. 
     Refer to  FIG. 4  for the system flow chart of the invention. First, at step  401 , initially, the determination level TMC_ON is 0, it means that TMC power supply end of the system does not provide electric power. If a device is connected in such a condition, the system proceeds determination. If the level of USB/TMC# is 1, it means that the connecting device is a general USB device (i.e. not a TMC device). At step  402 , the system determines whether the level of USB_CABLE_DET is 1. If the level is 1, the step  403  is processed to activate connection with the USB device, and data signals are transmitted through the contacts USBN− and USBP+ to the satellite navigation device. Meanwhile, the level of TMC_ON is 0, it means that the power supply of the satellite navigation device is provided by the connecting USB device. If the level of the USB_CABLE_DET is 0, it means that the connecting device is not a USB device, then no change occurs to the satellite navigation device at step  404 . 
     In another condition, if the level of the USB/TMC# is 0, it means that the connected device is a TMC device. At step  405 , determine whether the level of the USB_CABLE_DET is 1. If the level is 0, connection of the TMC device at step  406  is activated. If the level of the TMC_ON changes to 1, the satellite navigation device provides power supply to the TMC device. On the contrary, if the level of USB_CABLE_DET is 1, enter step  407 , namely the TMC device is not functioning; the satellite navigation device performs charging function, and the level of the TMC_ON is 0. 
     Knowing the invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.