GPS bus automatic stop announcement system based on 51 single chip microcomputer

1. Hardware Solution

This design is mainly to produce a GPS automatic bus stop announcement based on 51 single-chip microcomputer. According to the design requirements, the hardware part should have the functions of GPS positioning, voice broadcast, LCD display, key operation and corresponding indicator light prompts. Therefore, this design uses STC89C58RC single-chip microcomputer as the main control chip, GPS module uses VK2828U7G5LF, LCD display part uses LCD12864 liquid crystal, audio playback part uses Miniplay module, and key circuit, indicator light prompt circuit also adds clock display circuit. The overall hardware block diagram is shown in the figure:

2. Design function

(1) There are two main ways of announcement in this design. One is that when arriving at the announcement station, the driver presses the corresponding button to make an announcement; the other is a fully automatic voice announcement method. When arriving at the announcement station, the design will automatically make an announcement.

(2) It has a built-in clock display and a GPS automatic time calibration switch. When the calibration button is pressed, the current time data will be automatically calibrated once each time the power is turned on if valid GPS data is received. Pressing the button again will turn off the automatic GPS time calibration function, but the manual debugging function is supported.

(3) The clock chip is equipped with a button battery. When the system loses power, the button battery continues to work; after powering on again, the time does not need to be reset;

(4) The volume of the voice broadcast can be adjusted by pressing the button.

(5) There are two ways to modify the latitude and longitude data during automatic broadcasting. One is to fix the program and cannot be modified. The other is to customize the latitude and longitude data. The user can stand at the location where the broadcast is desired with the device, select the corresponding menu, and press the corresponding button when the GPS data is stable to enter the latitude and longitude data of the station name.

3. Design Schematic

(1) The schematic diagram is mainly designed using AD software, as shown in the figure:

(2) The PCB diagram is as follows:

4. Software Design

(1) Program flow chart

(2) Main program source code

void main()

 {

   TimeInt();

   LCD12864_init();      //Call display function

// Send_Appoint_Music(1);

   read_memory();

Mode=0;

   if(Mode) 

    {

  read_GPS();

}

   while(1) 

    {  

  read_time1(); //Read time function, GPS_Write is equal to 1, indicating that the GPS to be acquired is assigned to the time

  GPS_Route_Dispose();

  Display(); //Display function

  key_dispose(); //Key processing function

  memory();

  memory_GPS();

  led_dispose();

  if(Busy == 0) 

   {

     if(Sound_flag)

  {  

    Sound_flag=0;

    Send_Appoint_Sound(Sound); 

  }

   }

}

 }