Need Serious Help

The DB9 connector,J5,in the dev board is RS232.Do not connect the RFID to this.
Instead tap the P0.4 and P0.5 ttl Rx/Tx signals from the connector J3.

For working with the COM port using VB's MSCOMM control refer to this thread...
http://www.8051projects.net/forum-t5021-0.html#post_5060

Also make sure no other device/modem is using the com port you are trying to communicate with.

sashijoseph, why cant i connect RFID to microcontroller J5?

Hmm I want to ask about the expander, if I have an expander for serial port, like on the page 1 of this forum, if connect them at the same time with no switch, will there be any clash?

Cause I was thinking for RFID, if I link 1 of them to computer and another one to microcontroller, then the linking should be complete.

But is my theory correct?

according to what shashi says...
you have two serial outputs..
1. TTL (Tx-Rx pair direct from port pins)J3.
2. RS232 level Tx-rX (j5).
so if u want to connect rfid directly to the uC do as shashi says.

o ok. thanks!

I wan to ask whether is it normal when I send this string "qweqwe" to serial port and when i read it, it return "n"

guys what if I wan to try whether if I pass in 5 volt, the microcontroller will read as "1" and when I switch off, it will pass in "0". can be it done with my development board?

hi spiritgate

o ok. thanks!

I wan to ask whether is it normal when I send this string "qweqwe" to serial port and when i read it, it return "n"

if u really need help then please add details to your question..
how are u sending qweqwe (PCto uC or uC to PC and how?)
similarlyhow are u reading?

for ur second ques..
yes can be done.

make any port pin as input.
now check if that pin receives high (1)
if yes then transmit /send "1"
else "0"

for the second question right, when i try to connect it to the LED together with a wire connecting to serial port (2) and another connecting to serial port (5). also it is connecting to the female side. Then when I put them together, it light up! is it normal?

Then I follow the code given in page 1, so if it is high, SUBF0 will be equal to "1" or 0x01?

Thanks:)

Do I need to set any timer or interrupt for the controller?because i tried it but is not working..

For the first question, I am sending it to com port 1.

This is my code:

Set objComport = CreateObject( "ActiveXperts.Comport" )    ' Create a new Comport instance

   objComport.Device              = "COM1"                    ' Use a COM port directly (no Windows Device Driver)
   objComport.BaudRate            = 9600
   objComport.Open                                            ' Open the port
  ' Wscript.Echo "Open, result: " & objComport.LastError
   If( objComport.LastError <>
 0 ) Then
     output.text = "Quit"
   End If

    objComport.WriteString( "0" )                           ' Write command
   str = objComport.ReadString
   'WScript.Echo "Received: [" & str & "]"
      output.text =      "Received: [" +str + "]"
      objComport.Close

Anyone know is there any free virtual breadboard software? Because I want to check whether my connection is correct or not. thanks!

Guys help me double check....

If I want to communicate with serial port, the things that I do are:

//-----------------------------------------------------------------------------
// Blinky.c
//-----------------------------------------------------------------------------
// Copyright 2005 Silicon Laboratories, Inc.
//
// AUTH: BD
// DATE: 06 FEB 04
//
// This program flashes the green LED on the C8051F35x target board about
// five times a second using the interrupt handler for Timer2.
//
// Target: C8051F35x
//
// Tool chain: KEIL Eval 'c'
//




//-----------------------------------------------------------------------------
//How Program Works?
//-----------------------------------------------------------------------------
//The variable start with seat represent the priority seats in the train
//the seats will given a number,
//"0" means Lights off
//"1" means lights on but without blinking
//"2" means lights on with blinking
//"3" means occupy by priority people
//"4" means occupy by non-priority people




//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <c8051f350.h>
 
#include <stdlib.h>

#include <stdio.h>
  

                  
//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F35x
//-----------------------------------------------------------------------------

sfr16 TMR2RL   = 0xca;                    // Timer2 reload value
sfr16 TMR2     = 0xcc;                    // Timer2 counter

//-----------------------------------------------------------------------------
// Global CONSTANTS
//-----------------------------------------------------------------------------

#define SYSCLK       24500000 / 8         // SYSCLK frequency in Hz

sbit LED1 = P0^0;  
sbit LED2 = P0^1;
sbit LED3 = P0^2;
sbit LED4 = P0^3;

sbit LED7 = P0^6;
sbit LED8 = P0^7;
sbit LED9 = P1^0;
sbit LED10 = P1^1;
sbit LED11 = P1^2;
sbit LED12 = P1^3;
sbit LED13 = P1^4;
sbit LED14 = P1^5;
sbit LED15 = P1^6;
sbit LED16 = P1^7;
sbit nLED = P2^0;

 
                      // LED='1' means ON
sbit SW2 = P1^0; 
int i;
int start;
unsigned int h;
unsigned int p;
unsigned int j;
int testing123=0;
unsigned int seat[17];
unsigned int section;
unsigned char serialNumber[20];
unsigned char a;
unsigned int counter;
unsigned int track;//collect the data that RFID has pass, also act as a stopper





              
		          

//-----------------------------------------------------------------------------
// Function PROTOTYPES
//-----------------------------------------------------------------------------
void SYSCLK_Init (void);
void PORT_Init (void);
void Timer2_Init (int counts);
void Timer2_ISR (void);
void Click (void);
void checkSection (void);
void serial_init();
unsigned char serial_read();
void blinking (void);
void variable_Init(void);
void serial_send(unsigned char dat);

//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
void main (void) {

	  j=0;
 if(testing123==0){
	for(i=4; i<8;i++){
	seat[i] = 0;
	 }
	 testing123=1;
	 }
 start=1;

   variable_Init();
   //section=2;//testing purpose
  // track=1;//testing purpose
  
   // disable watchdog timer
   PCA0MD &= ~0x40;                       // WDTE = 0 (clear watchdog timer

   

   SYSCLK_Init ();                        // Initialize system clock
   PORT_Init ();
   serial_init();

   
//------------------------------------------------------------------------    
while (start) {  
  PCA0MD &= ~0x40;
    serial_init();


a=serial_read();

if(a==0x00){
LED7 = 1;
}

   SYSCLK_Init ();                        // Initialize system clock
   PORT_Init ();
 

//where a cycle ends	
if(counter==800){
variable_Init();
counter=0;
track=0;
start=0;
main();
testing123=10;
}

//delay
for (i = 0; i < 10000; i++)  {  /* Delay for 10000 Counts */
                            /* call wait function */
}

//------------------------------------------------
//Switch testing purpose
//------------------------------------------------

while(SW2==0){

if(section==0 && track ==0){
     section=2;
  track=1;
     counter=1;
      
	 for (i = 0; i < 18000; i++)  {  /* Delay for 10000 Counts */
                            /* call wait function */
}
 

  
}else{
if(seat[7]==3 && seat[6]==3){
seat[7]=4;
seat[6]=4;
seat[5]=4;
seat[4]=4;
}else{
if(seat[7]==3){
seat[6]=3;
}else{
seat[7]=3;
}
}
counter = 799;
start=0;
testing123=10;
 main();


}

}


//-----------------------------------------------
if(track==2){
nLED = ~nLED;
}
//serial_read();//read from serial port
if(track==1){
checkSection();//check priority seats
blinking();

} //determine which seats to light up
 counter++;

}//end main routine
//-----------------------------------------------------------------------------------


   EA = 1;											// enable global interrupts

   
}

//-----------------------------------------------------------------------------
// SYSCLK_Init
//-----------------------------------------------------------------------------
//
// This routine initializes the system clock to use the internal 24.5MHz / 8
// oscillator as its clock source.  Also enables missing clock detector reset.
//
void SYSCLK_Init (void)
{
   OSCICN = 0x80;                         // configure internal oscillator for
                                          // its lowest frequency
   RSTSRC = 0x04;                         // enable missing clock detector
}
//-----------------------------------------------------------------------------
// serial_Init
//-----------------------------------------------------------------------------
void serial_init(){
        TMOD = 0x20;  
        SCON0 = 0x50;
        TH1  = 0xFD;
        TL1  = 0xFD;
        TR1  = 1;
}


//-----------------------------------------------------------------------------
// serial_read
//-----------------------------------------------------------------------------
//
// To read data from SBUF0

// 
unsigned char serial_read(){
         while(!RI0);
        RI0 = 0;
        return SBUF0;
}

//-----------------------------------------------------------------------------
// Blinking
//-----------------------------------------------------------------------------
//
void blinking (void){
if(seat[0]==1){
LED1 = 1;
}
if(seat[1]==1){
LED2 = 1;
}
if(seat[2]==1){
LED3 = 1;
}
if(seat[3]==1){
LED4 = 1;
}

if(seat[6]==1){
LED7 = 1;
}
if(seat[7]==1){
LED8 = 1;
}
if(seat[8]==1){
LED9 = 1;
}
if(seat[9]==1){
LED10 = 1;
}
if(seat[10]==1){
LED11 = 1;
}
if(seat[11]==1){
LED12 = 1;
}
if(seat[12]==1){
LED13 = 1;
}
if(seat[13]==1){
LED14 = 1;
}
if(seat[14]==1){
LED15 = 1;
}
if(seat[15]==1){
LED16 = 1;
}

 
 
	if(seat[0]==2){
      LED1 = ~LED1;
    }
    if(seat[1]==2){
      LED2 = ~LED2;
    }
    if(seat[2]==2){
      LED3 = ~LED3;
    }
    if(seat[3]==2){
      LED4 = ~LED4;
    }
   
    if(seat[6]==2){
      LED7 = ~LED7;
    }
    if(seat[7]==2){
      LED8 = ~LED8;
    }
    if(seat[8]==2){
      LED9 = ~LED9;
    }
    if(seat[9]==2){
      LED10 = ~LED10;
    }
    if(seat[10]==2){
      LED11 = ~LED11;
    }
    if(seat[11]==2){
      LED12 = ~LED12;
    }
    if(seat[12]==2){
      LED13 = ~LED13;
    }
    if(seat[13]==2){
      LED14 = ~LED14;
    }
    if(seat[14]==2){
      LED15 = ~LED15;
    }
    if(seat[15]==2){
      LED16 = ~LED16;
    }
                  
}



void variable_Init(void){

 counter=0;
 section=0;
 LED1 = 0;
 LED2 = 0;
 LED3 = 0;
 LED4 = 0;

 LED7 = 0;
 LED8 = 0;
 LED9 = 0;
 LED10 = 0;
 LED11 = 0;
 LED12 = 0;
 LED13 = 0;
 LED14 = 0;
 LED15 = 0;
 LED16 = 0;
 nLED = 0;
 track = 0;

}
//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Configure the Crossbar and GPIO ports.	
// P0.7 - LED (push-pull)
//
void PORT_Init (void)
{
   XBR0     = 0x00;                       // no digital peripherals selected
   XBR1     = 0x40;                       // Enable crossbar and weak pull-ups
   P0MDOUT |= 0xFF;                       // enable LED as a push-pull output
   SW2 = 1;
  //P1MDOUT |= 0xFF; 
   P1MDIN |= 0xFF;                   
}
void Click (void)  
{                  
                    /* only to delay for LED flashes */
}





void checkSection (void)
{
//---------------------------------------------------------------------
//section 1
//---------------------------------------------------------------------
if(section==1){

if(seat[1]>
2 && seat[0]>
2 && seat[2] >
2 && seat[3]>
2){
	

	 for(i=0; i<4; i++){
        if(seat[i]==4){
           seat[i]=2;
        }
     }
	 //------------------------------------------------------------
     if(seat[5]==0 || seat[4]==0 || seat[7]==0 || seat[6]==0){
	     for(i=4; i<8; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
	
	 }
	 //-------------------------------------------------------------
	 else if(seat[9]==0 || seat[10]==0 || seat[11]==0 || seat[8]==0){
	 for(i=8; i<12; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
	 }
	 //--------------------------------------------------------------
	 else if(seat[13]==0 || seat[14]==0 || seat[15]==0 || seat[12]==0){
	 for(i=12; i<16; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
	 }
	 //---------------------------------------------------------------

}else{
         for(i=0; i<4; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
}//end else
section=0;
}
//---------------------------------------------------------------------
//Section 2
//---------------------------------------------------------------------
if(section==2){
if(seat[5]>
2 && seat[4]>
2 && seat[7]>
2 && seat[6]>
2){
      for(i=4; i<8; i++){
           if(seat[i]==4){
              seat[i]=2;
           }
         }
	 //----------------------------------------------------------	 
     if(seat[2]==0 || seat[3]==0 || seat[9]==0 || seat[8]==0){
	  if(seat[3]==0){
	     seat[3] = 1;
	  }if(seat[2]==0){
	     seat[2] = 1;
	  }if(seat[9]==0){
	     seat[9] = 1;
	  }if(seat[8]==0){
	     seat[8] = 1;
	  }
	 }
	 //-----------------------------------------------------------
	 else if(seat[0]==0 || seat[1]==0 || seat[11]==0 || seat[10]==0){
	  if(seat[0]==0){
	      seat[0] = 1;
	 }if(seat[1]==0){
	      seat[1] = 1;
	 }if(seat[11]==0){
	      seat[11] = 1;
	 }if(seat[10]==0){
	      seat[10] = 1;
	 }
	 }
	 //------------------------------------------------------------
	 else if(seat[13]==0 || seat[14]==0 || seat[15] ==0 || seat[12]==0){
	    for(i=12; i<16; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
	 }
	 //-------------------------------------------------------------
}else{
        for(i=4; i<8; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
}//end else
section=0;
}
//---------------------------------------------------------------------
//Section 3
//---------------------------------------------------------------------
if(section==3){
if(seat[8]>
2 && seat[9]>
2 && seat[10]>
2 && seat[11]>
2){
		 for(i=8; i<12; i++){
           if(seat[i]==4){
              seat[i]=2;
           }
         }

     //-----------------------------------------------------------------
     if(seat[6]>
0 && seat[7]>
0 && seat[13] >
0 && seat[12]>
0){
	 if(seat[6]==0){
	 seat[6] = 1;
	 }if(seat[7]==0){
	 seat[7] = 1;
	 }if(seat[13]==0){
	 seat[13] = 1;
	 }if(seat[12]==0){
	 seat[12] = 1;
	 }
	 }
	 //------------------------------------------------------------------
	 else if(seat[15]>
0 && seat[14]>
0 && seat[4] >
0 && seat[5]>
0){
	  if(seat[5]==0){
	 seat[5] = 1;
	 }if(seat[15]==0){
	 seat[15] = 1;
	 }if(seat[14]==0){
	 seat[14] = 1;
	 }if(seat[4]==0){
	 seat[4] = 1;
	 }
	 }
	 //-------------------------------------------------------------------
	 else if(seat[1]>
0 && seat[2]>
0 && seat[3] >
0 && seat[0]>
0){
	  if(seat[1]==0){
	    seat[1] = 1;
	 }if(seat[2]==0){
	 seat[2] = 1;
	 }if(seat[3]==0){
	 seat[3] = 1;
	 }if(seat[0]==0){
	 seat[0] = 1;
	 }
	 }
	 //--------------------------------------------------------------------
}else{
        for(i=8; i<12; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
}//end else
section=0;
}
//---------------------------------------------------------------------
//Section 4
//---------------------------------------------------------------------
if(section==4){
if(seat[13]>
2 && seat[14]>
2 && seat[15] >
2 && seat[12]>
2){
        for(i=12; i<16; i++){
           if(seat[i]==4){
              seat[i]=2;
           }
         }
     if(seat[9]>
0 && seat[10]>
0 && seat[11] >
0 && seat[8]>
0){
	  for(i=8; i<12; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
	 }
	 else if(seat[4]>
0 && seat[5]>
0 && seat[6] >
0 && seat[7]>
0){
	  for(i=4; i<8; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
	 }
	 else if(seat[0]>
0 && seat[1]>
0 && seat[2] >
0 && seat[3]>
0){
	  for(i=0; i<4; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
	 }
}else{
        for(i=12; i<16; i++){
           if(seat[i]==0){
              seat[i]=1;
           }
         }
}//end else
}//end if IF
section=0;
}//end void
//-----------------------------------------------------------------------------
// Timer2_Init
//-----------------------------------------------------------------------------
//
// Configure Timer2 to 16-bit auto-reload and generate an interrupt at
// interval specified by <counts>
 using SYSCLK/48 as its time base.
//
void Timer2_Init (int counts)
{
 
   TMR2CN  = 0x00;                        // Stop Timer2; Clear TF2;
                                          // use SYSCLK/12 as timebase
   CKCON  &= ~0x60;                       // Timer2 clocked based on T2XCLK;

   TMR2RL  = -counts;                     // Init reload values
   TMR2    = 0xffff;                      // set to reload immediately
   ET2     = 1;                           // enable Timer2 interrupts
   TR2     = 1;
   
                            // start Timer2
}

//-----------------------------------------------------------------------------
// Interrupt Service Routines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// Timer2_ISR
//-----------------------------------------------------------------------------
// This routine changes the state of the LED whenever Timer2 overflows.
//
void Timer2_ISR (void) interrupt 5
{
   TF2H = 0;                              // clear Timer2 interrupt flag
   LED1 = ~LED1;  
   LED1 = ~LED1;                          // change state of LED
}

is it correct? like that can communicate with port 1? If this one can then my problem now is with the circuit. Because I need to pass a "1" or "0" to the serial port. And if it reads it, 1 of the LED on the development board will light up.


Thanks!