CN104539500B - A kind of external device extension method of car-mounted terminal - Google Patents

Abstract

The present invention provides a method for expanding external equipment of a vehicle-mounted terminal, comprising the following steps: Step 1, the vehicle-mounted terminal is connected to the input end of a serial port box, the output end of the serial port box is connected to an external device, and step 2, the connection object of the serial port is set And the external device connected to the output end of the serial port box, step 3, when the vehicle-mounted terminal sends a packet of data, first group packets according to the communication protocol of the serial port box, get the packet one, and then send the packet one to the serial port box, the serial port box Analyze according to the communication protocol, and then send the data packet one to the external device according to the extended ID; when the external device sends the data packet two to the vehicle terminal, the serial port box receives the data packet two and follows The communication protocol is grouped into packets to obtain the second packet, and the vehicle-mounted terminal is analyzed according to the communication protocol to obtain the second data packet. The invention realizes the diversification of serial port external devices and realizes the function that one serial port can be connected to multiple external devices at the same time.

Description

A method for extending external equipment of a vehicle-mounted terminal

【Technical field】

The invention relates to a method for expanding external equipment of a vehicle-mounted terminal.

【Background technique】

Cars usually need to connect multiple external devices, usually through serial ports to connect external devices to achieve specific functions, for example, it is necessary to connect a driving recorder to record the driving status of the vehicle in real time, but. The needs of different customers will also be different. For example, taxis need to be connected to the meter to record the operation status, and buses need to record the bus operation status through the camera. Traditional vehicle-mounted terminals generally only provide 2 to 3 serial ports for connecting external devices. With the increasing functional requirements of customers, more and more peripherals are connected, and traditional vehicle-mounted terminals can no longer meet customer needs. In order to meet the customer's needs for connecting multiple external devices and develop a new vehicle-mounted terminal with more serial ports, not only the new product cycle is long, but also the development cost is high, which is obviously not advisable.

【Content of invention】

The technical problem to be solved by the present invention is to provide a vehicle-mounted terminal external device expansion method, which realizes the diversification of serial port external devices and realizes the function that one serial port can connect multiple external devices at the same time without changing the original vehicle-mounted terminal hardware.

The present invention is achieved like this: 1, a kind of external equipment expansion method of vehicle-mounted terminal, it is characterized in that, comprises the steps:

Step 1. Connect the input end of a serial port box with the serial port of the vehicle-mounted terminal, connect at least one external device with the output end of the serial port box, and the serial port box includes at least two output ports;

Step 2, setting the connection object of the serial port through the vehicle-mounted terminal as a serial port box, and configuring the serial port parameters of different external devices connected to the serial port box, the serial port parameters include the extended ID of each output terminal;

Step 3, when the vehicle-mounted terminal sends a data packet to one of the external devices, the data packet is first grouped according to the communication protocol of the serial port box to obtain a group packet, and then its group packet is sent to the serial box, The communication protocol defines that the group package 1 includes the extension ID, and the serial port box analyzes according to the communication protocol to obtain the data packet 1, and then sends the data packet 1 to the external device according to the extension ID ;

When the external device sends the data packet 2 to the vehicle terminal, the serial box receives the data packet 2 and performs grouping according to the communication protocol to obtain the group packet 2, and the serial port box sends the group packet 2 to the The vehicle-mounted terminal, the vehicle-mounted terminal analyzes according to the communication protocol to obtain the second data packet, and the communication protocol also defines that the second group packet contains the extended ID.

Further, the data format of the group package 1 includes a frame header, a device identification code of a serial port box, a command identifier including the extended ID, parameter content, a checksum, and a frame trailer.

Further, the data format of the group package 2 includes a frame header, the device identification code of the serial port box, the extension ID, data content, and a frame tail.

The present invention has the following advantages:

The vehicle-mounted terminal of the present invention identifies the external device corresponding to each data packet through the extended ID, and the serial port box identifies the data transmission object through the extended ID. Under the condition that the vehicle-mounted terminal hardware does not change, a single serial port can be externally connected to various external devices to meet the needs of customers' external devices. Add requirements.

【Description of drawings】

The present invention will be further described below in conjunction with the embodiments with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of connection between a vehicle-mounted terminal and an external device according to the present invention.

Fig. 2 is a flow chart of data transmission from the vehicle-mounted terminal to the external device according to the present invention.

Fig. 3 is a flowchart of the transmission of external data to the vehicle-mounted terminal according to the present invention.

【Detailed ways】

Please refer to Fig. 1 to Fig. 3, a kind of external device expansion method of vehicle terminal, comprises the following steps:

Step 1, the input end of a serial port box is connected with the serial port of vehicle-mounted terminal, at least one external device is connected with the output end of described serial port box, and described serial port box comprises at least two output ends; Described external device can be camera, Calculator, LED display, driving recorder;

Step 2, setting the connection object of the serial port through the vehicle-mounted terminal as a serial port box, and configuring the serial port parameters of different external devices connected to the serial port box, the serial port parameters include the extended ID of each output terminal;

Step 3, when the vehicle-mounted terminal sends a data packet to one of the external devices, the data packet is first grouped according to the communication protocol of the serial port box to obtain a group packet, and then its group packet is sent to the serial box, The communication protocol defines that the group package 1 includes the extension ID, and the serial port box analyzes according to the communication protocol to obtain the data packet 1, and then sends the data packet 1 to the external device according to the extension ID ; In this embodiment, the data format of the group package 1 includes the frame header, the device identification code of the serial port box, the command identification including the extended ID, the parameter content, the checksum and the frame tail.

When the external device sends the data packet 2 to the vehicle terminal, the serial box receives the data packet 2 and performs grouping according to the communication protocol to obtain the group packet 2, and the serial port box sends the group packet 2 to the The vehicle-mounted terminal, the vehicle-mounted terminal analyzes according to the communication protocol, and obtains the data package 2, and the communication protocol also defines that the group package 2 contains the extended ID. In this embodiment, the group package 2 The data format includes the frame header, the extended ID of the device identification code of the serial port box, the data content and the frame tail.

The vehicle-mounted terminal of the present invention identifies the external device corresponding to each data packet through the extended ID, and the serial port box identifies the data transmission object through the extended ID. Under the condition that the vehicle-mounted terminal hardware does not change, a single serial port can be externally connected to various external devices to meet the needs of customers' external devices. Add requirements.

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments we have described are only illustrative, rather than used to limit the scope of the present invention. Equivalent modifications and changes made by skilled personnel in accordance with the spirit of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (3)

1. A method for expanding external equipment of a vehicle-mounted terminal, comprising the steps of: Step 1. Connect the input end of a serial port box with the serial port of the vehicle-mounted terminal, connect at least one external device with the output end of the serial port box, and the serial port box includes at least two output ports; Step 2, setting the connection object of the serial port through the vehicle-mounted terminal as a serial port box, and configuring the serial port parameters of different external devices connected to the serial port box, the serial port parameters include the extended ID of each output terminal; Step 3, when the vehicle-mounted terminal sends a data packet to one of the external devices, the data packet is first grouped according to the communication protocol of the serial port box to obtain a group packet, and then its group packet is sent to the serial box, The communication protocol defines that the group package 1 includes the extension ID, and the serial port box analyzes according to the communication protocol to obtain the data packet 1, and then sends the data packet 1 to the external device according to the extension ID ; When the external device sends the data packet 2 to the vehicle terminal, the serial box receives the data packet 2 and performs grouping according to the communication protocol to obtain the group packet 2, and the serial port box sends the group packet 2 to the The vehicle-mounted terminal, the vehicle-mounted terminal analyzes according to the communication protocol to obtain the second data packet, and the communication protocol also defines that the second group packet contains the extended ID. 2. The external device extension method of a vehicle-mounted terminal according to claim 1, wherein the data format of said group package one includes a frame header, a device identification code of a serial port box, and a command identification comprising said extended ID , parameter content, checksum, and frame trailer. 3. The external device extension method of a kind of vehicle-mounted terminal according to claim 1, characterized in that, the data format of said group package two includes said extension ID, data content and frame of the device identification code of frame header, serial port box tail.