Help Needed in Connecting PIC to PC via USB

Replies

• 

  Harshad Italiya

  I think C language is good platform for this project
• 

  Harshad Italiya

  Take a look here for interfacing Circuit.
  #-Link-Snipped-#
• 

  mohit30goel

  mosh11

  Currently i am doing my bachelor project.
  
  the idea of the project is to control several devices and systems using PC, i will connect the PC to PIC using USB interface
  
  i already found the circuit and connected it and also the pc (windows xp sp2) identified my circuit as Human Interface device(HID).
  
  ● The problem now how can i test this connection(how do i send and receive data between both terminals)?
  
  
  ● Which program language or platform can i use to have access to usb port in the PC?
  
  
  --here is code that i downloaded to the PIC microcontroller
  
  1-The interrupt part for keeping the connection alive by sending message every 3.3ms
  
  2-When pic receives (P=??) it is expected to send to PC data on PORTC
  
  When it receives (P=nT) it is expected to output n in PORTB
  
  

  #include "C:\Program Files\Mikroelektronika\mikroC\Examples\EasyPic4\extra_examples\HID-library\USBdsc.c"
  unsigned char Read_buffer[64];
  unsigned char Write_buffer[64];
  unsigned char num,x;
  //
  // Timer interrupt service routine
  //
  void interrupt()
  {
  HID_InterruptProc(); // Keep alive
  TMR0L = 100 ; // Re-load TMR0L
  INTCON.TMR0IF = 0 ;  // Reload TMR0
  }
   
   
  void main()
  {
   
  ADCON1 = 0xFF; // Set PORTB to digital I/O
  TRISB=0; // Set PORTB to outputs
  TRISD=0;
  TRISC=1;
  PORTD=0;
  PORTB = 0; // Clear all outputs
   
  INTCON=0;
  INTCON2=0xF5;
  INTCON3=0xC0;
  RCON.IPEN=0;
  PIE1=0;
  PIE2=0;
  PIR1=0;
  PIR2=0;
  //
  // Configure TIMER 0 for 3.3ms interrupts. Set prescaler to 256
  // and load TMR0L to 100 so that the time interval for timer
  // interrupts at 48MHz is 256.(256-100).0.083 = 3.3ms
  //
  // The timer is in 8-bit mode by default
  //
  T0CON = 0x47; // Prescaler = 256
  TMR0L = 100; // Timer count is 256-156 = 100
  INTCON.TMR0IE = 1; // Enable T0IE
  T0CON.TMR0ON = 1; // Turn Timer 0 ON
  INTCON = 0xE0; // Enable interrupts
   
  // Enable USB port
   
  Hid_Enable(&Read_buffer, &Write_buffer);
  Delay_ms(2000);
   
  // Read from the USB port. Number of bytes read is in num
   
  for(;;) // do forever
  {
   
  if(Read_buffer[0]=='P' && Read_buffer[1]=='=' && Read_buffer[2]=='?' && Read_Buffer[3]=='?' ){
   
   
  while(!Hid_Write(PORTC, 1)){
                     x = Hid_Write(PORTC, 1);
                     }
  }
   
   // Read from the USB port. Number of bytes read is in num
   
  if(Read_buffer[0] == 'P' && Read_buffer[1] == '=' && Read_buffer[3] == 'T')
  {
  if(Read_buffer[2]=='1'){
  PORTD=1; // opens gate
  }
  PORTB = Read_buffer[2];
  }
  }
  Hid_Disable();
  }
   
   
   
  

  
  
  Its not a much bigger problem man....? u can test ur connections over making a locan lan panel b/w no. of computers u have..u can also try for the php server method .....that can also be beneficial 4 u???
• 

  debu

  @mosh11: Debu's Innovations: USB-101 should help you. It explains how to write both PC side and Device side USB code, meant for beginners.
  
  Hope this helps,
  
  Regards,
  
  Debu 😀