problem in receving message with pic16f877a

[kittythakur]

heelo guys …. i m making project to switch on and off led by sms….i m using p16f877a with sim900a modem 

 

i m able to send message from modem to mobile but i m getting problem while receiving text

 

i m using AT+CMGR=1 

and getting +CMGR: “REC READ”,”+917696897725″,,”12/07/22,14:24:11+22″

#a1

 

i want to extract #a1 from the string and rest string i want to skip 

i apllied various logic but did’t get right output

 

here is my code

 

if(UART1_Data_Ready()>0)

 {

inchar=UART1_Read();

i++;

delay_ms(10);

        if (inchar==’#’)

        {i++;

        if(inchar==’o)’

        {i++;

        if(inchar==’n’)

 

                {led=1;}

          else if (inchar==’f’)

        {led=0;}

        }

        }

        else {led=0;Tx();delay_ms(10);inchar=UART1_Read();UART1_Write_Text(“AT+CMGD=1,4”);UART1_Write(0x0D); }

        }

 

can anybody correct my code ????

[AJISH ALFRED]

Hi,

Put that piece of code inside the infinite loop

 

while (1)

{

/////// code /////

}

[kittythakur]

Thanks for reply 

 

actaully i apllied this code in infinite loop …you can check this

 

 

 

while(1)

{ UART1_Init(9600);

delay_ms(500);

UART1_Write_Text(“ATeo”);

UART1_Write(0x0D);

delay_ms(300);

UART1_Write_Text(“AT+CMGF=1”);

UART1_Write(0x0D);

delay_ms(300);

UART1_Write_Text(“AT+CNMI=2,2,0,0” );

UART1_Write(0x0D);

delay_ms(300) ;

UART1_Write_Text(“AT+CMGR=1”) ;

UART1_Write(0x0D);

delay_ms(300);

 

led1=1 ;

if(UART1_Data_Ready()>0)

 {

 while (UART1_Read()==’’)

 {

inchar=UART1_Read();

i++;

delay_ms(10);}

 

        if (inchar[0]==’#’)

        {i++;

        if(inchar[1]==’o’)

        {i++;

        if(inchar[2]==’n’)

 

                {led=1;}

          else if (inchar[2]==’f’)

        {led=0;}

        }

        }

else led=0;Tx();delay_ms(10);inchar=UART1_Read();UART1_Write_Text(“AT+CMGD=1,4”);UART1_Write(0x0D);

        }

        }

        }

 

 

 

now tell me what to do ???

it is not working ….can any body correct this??

[Rajesh K]

yes… ur code hs a few prblems I cn see. U r using MikroC, yes?

 

what is ur current state….? do u hv a deadline when this musst b fixed?

[kittythakur]

rakesh thanx for reply

 

yes m using micro c and i having problem in receiving data .can u plz tell me how to properly receive data,store in variable and compare with any string .you can see my code .

 plz its urgent

 

[Rajesh K]

many ways 2 debug this… some loops r wrong (or too complx  til bugs r fixd). ur code has no err chking so how can u find the problem???

 

examples:

 

add serial tap 2 chk io to sim900a (connect 2 pc via max232 or similr n thn use hyprterm)

 

or add i2c lcd display n add code to out all recd data to lcd

 

or add soft uart code in microc compiler n out all recd data to it

 

or use microc sw simulatr

[Rajesh K]

when i do this proj in past,,, i use differnt algo to u ,,,,, eg init UART once, setup sim900 once, then loop waiting 4 chars to start, then loop reading chars into buffer or state machne testing 4 cmd start char eg #, then action on recd cmd (led, relay,,,), then back to loop waiting 4 chars. u shld not need delay_ms after UART1_Read!
 

[kittythakur]

thnx rakesh 

 i tried as u said 

  Now i m checking my code in proteous with the help of  virtual terminal     i applied logic in which what i send to rx pin i should get in tx pin ,but when i send “#ON” to rx pin then i get “#NNN” or other garbage value

 

 

case:2- sometimes if i send ‘#on’  ..i got #on on tx pin

but if i send long string to rx pin then i only get 3 character accurate but after 3 character i get garbage value again

[Rajesh K]

i hv not used proteous in that way so unless u know it vry well, you can add more prblems instead of solve them!

 

ur reslts cn happn eg due to ur exact new code this is y i wud use serial tap – no new code needed!

 

remembr p18f877a uart rx fifo is very small – mayb u need to chk for rx over run, if u do to much than just rx chars

 

 

[kittythakur]

thnx rakesh- 

 

i only want toknow how i can store received string into a variable 

 

 

problem is here “inchar=UART1_Read();”

 

i cant suceesfully store data into “inchar” from UART1_Read  

 

actaully i want to print received data on LCD 16*2 ,i tried many times but i get wrng result

can u tell me how to correct this code.how can i print received string on lcd

[Rajesh K]

>problem is here “inchar=UART1_Read();”
>i cant suceesfully store data into “inchar” from UART1_Read  

 

1. how do u kno data fm UART1_Read() is gud?

2. what exact prblem u get – compile err? run err? what?  same problem every time (with same SMS txt) or no?

3. only when 2 points abve r clear, then we discuss how to stor gud data. OK bro?

 

>actaully i want to print received data on LCD 16*2 ,i tried many times but i get wrng result
>can u tell me how to correct this code.how can i print received string on lcd

 

fix depnds on ur hw (pic+lcd+circuit) and sw (code+lib).

 

[kittythakur]

1. how do u kno data fm UART1_Read() is gud?

hello dear,   actaully m running my code in proteous bcoz my hyperterminal and com port is not wroking well.i m using virtual terminal with receiving and transmiting pin.,so when i give input on rx pin through virtual terminal ,it stores in  UART1_Read().after that i use UART1_Write(UART1_Read()); i get the same string on tx virtual terminal which i sent on rx pin.thats why i m saying UART1_Read is gud . but i want to store the string from UART1_Read() to  in a array,so that i can print data on lcd with the help of ” for loop. “

2. what exact prblem u get – compile err? run err? what?  same problem every time (with same SMS txt) or no?

i think, you got my problem now, . i m unable to store received data into a array

here  inchar=UART1_Read();

 

 

 

#define led1 PORTC.F1

#define led PORTC.F0

#define RS PORTC.F2

#define RW PORTC.F3

#define EN PORTC.F4

unsigned char inchar;

unsigned int i=0,j,k;

char buffer[80] ;

void Tx();

void cmd( unsigned char x)

{

PORTD=x;

RS=0;

RW=0;

EN=1;

delay_ms(100);

EN=0;

}

void dat ( unsigned char x )

{

PORTD=x;

RS=1;

RW=0;

EN=1;

delay_ms(100);

EN=0;

}

void int_lcd()

{

cmd(0x38);

cmd(0x0e);

 

cmd(0x06);

cmd(0x80);

}

  void rcv ()

 {

inchar=UART1_Read();   // i want to store received string in a buffer .and after that i want to print on lcd .i m having problem

delay_ms(100);

while(inchar!=’’)

{ 

 buffer=inchar;

i++;

}

 

}

 

void main()

{

TRISD=0x00;

TRISC=0x80;

led=0;

led1=0;

UART1_Init(9600);

delay_ms(300);

UART1_Write(0x0D);

delay_ms(300);

UART1_Write_Text(“AT+CMGF=1”);

UART1_Write(0x0D);

delay_ms(300);

UART1_Write_Text(“AT+CNMI=2,2,0,0” );

UART1_Write(0x0D);

delay_ms(300) ;

    int_lcd();

while(1)

{

led1=1 ;

if(UART1_Data_Ready()>0)

  {

  rcv();

for (j=0;j<=8;j++)

  {

  dat(buffer[j]);

  delay_ms(10);

 

  }

     cmd(0x01);

 

}

       // UART1_Write_Text(“AT+CMGD=1,4”);

 

}

}

firstly i want to controll led but now i want to  print data on lcd .

 

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