how to read a string line by line via rs232

[adnan_merter]

hi everybody,

i need to know how i can receive a string from rs232,

i mean (and already know the gets() and get_string() functions) i am sending a bunch of string without no time delay from pc to pic

and i need to read them line by line and compare each line whether it contains particular character and if it contains, pic should send it to the other pc

i already tried gets() function and it doesnt work,

here is my function, i have written to get each line seperately.

#include "main.h"
#include "LCD.c"
#include <string.h>

#use rs232(baud=9600,parity=N,xmit=PIN_C1,rcv=PIN_C0,bits=8,STOP=1, stream = PC2)
#use rs232(baud=300,parity=E,xmit=PIN_C6,rcv=PIN_C7,bits=7,STOP=1, stream = PC1)

static unsigned char ReceivedMsg[25];

static unsigned int1 endoftransmission = FALSE;

void Readline();

void main()
{

   setup_adc_ports(NO_ANALOGS|VSS_VDD);
   setup_adc(ADC_CLOCK_DIV_2);
   setup_spi(SPI_SS_DISABLED);
   setup_wdt(WDT_OFF);
   setup_timer_0(RTCC_INTERNAL);
   setup_timer_1(T1_DISABLED);
   setup_timer_2(T2_DISABLED,0,1);
   setup_ccp1(CCP_OFF);
   setup_comparator(NC_NC_NC_NC);
   setup_vref(FALSE);
   lcd_init();
   lcd_putc('\f');
   lcd_gotoxy(1,1);
//Setup_Oscillator parameter not selected from Intr Oscillator Config tab 
   
   // TODO: USER CODE!!

   fprintf(PC2,"WAITING FOR THE NECCESSARY VALUES");
   while(1)
   {
   while(!endoftransmission){ 
   Readline();
   fputs(ReceivedMsg,PC2);
   }
   }

}

void Readline()
{
memset(ReceivedMsg,0,sizeof(ReceivedMsg));
unsigned char MsgChar;
int k=0;
while(MsgChar != 0x0A)//getch() until LF char received
   {
      
      MsgChar = fgetc(PC1);   
     if(MsgChr=='!')
         endoftransmission=TRUE;
      ReceivedMsg[k] = MsgChar;
      k++;
   }
}

here is main.h

#include <18F2550.h>
#device adc=8

#FUSES NOWDT                 	//No Watch Dog Timer
#FUSES WDT128                	//Watch Dog Timer uses 1:128 Postscale
#FUSES HSPLL                 	//High Speed Crystal/Resonator with PLL enabled
#FUSES NOPROTECT             	//Code not protected from reading
#FUSES NOBROWNOUT            	//No brownout reset
#FUSES BORV20                	//Brownout reset at 2.0V
#FUSES NOPUT                 	//No Power Up Timer
#FUSES NOCPD                 	//No EE protection
#FUSES STVREN                	//Stack full/underflow will cause reset
#FUSES NODEBUG               	//No Debug mode for ICD
#FUSES NOLVP                 	//No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOWRT                 	//Program memory not write protected
#FUSES NOWRTD                	//Data EEPROM not write protected
#FUSES IESO                  	//Internal External Switch Over mode enabled
#FUSES FCMEN                 	//Fail-safe clock monitor enabled
#FUSES PBADEN                	//PORTB pins are configured as analog input channels on RESET
#FUSES NOWRTC                	//configuration not registers write protected
#FUSES NOWRTB                	//Boot block not write protected
#FUSES NOEBTR                	//Memory not protected from table reads
#FUSES NOEBTRB               	//Boot block not protected from table reads
#FUSES NOCPB                 	//No Boot Block code protection
#FUSES MCLR                  	//Master Clear pin enabled
#FUSES LPT1OSC               	//Timer1 configured for low-power operation
#FUSES NOXINST               	//Extended set extension and Indexed Addressing mode disabled (Legacy mode)
#FUSES PLL5                 	//Divide By 5(20MHz oscillator input)
#FUSES CPUDIV1             	//System Clock by 1
#FUSES USBDIV                	//USB clock source comes from PLL divide by 2
#FUSES VREGEN                	//USB voltage regulator enabled

#use delay(clock=48000000)

(i didnt work on the compare section yet)
i am using pic18f2550 and ccs c compiler, when i tried to run this code, it reads first line and it stops, Readline() function starts for a second line but it doesnt read the second line, everything looks fine but something is definately wrong.

waiting for your advices thanks

 

[FoxyRick]

A couple of things: You need to make sure that your serial-reading loop terminates before the ReceivedMsg variable overflows, and you have not initialised MsgChar - either initialise it before entering the while loop, or use a do...while loop instead.

I fail to see why gets() won't work, provided your string has a carriage return.

How are you programming the PIC - are you using the CCS ICD-U programmer?

Since you already have a serial output, try sending some debug information as well - like send a number for each line of your code, and the variable values, so that we can tell exactly where it stops. That's what I do if not using ICD. I have a serial VFD that I hook up just for that purpose even when not using the serial port for the program itself.

 

[adnan_merter]

A couple of things: You need to make sure that your serial-reading loop terminates before the ReceivedMsg variable overflows, and you have not initialised MsgChar - either initialise it before entering the while loop, or use a do...while loop instead.

I fail to see why gets() won't work, provided your string has a carriage return.

How are you programming the PIC - are you using the CCS ICD-U programmer?

Since you already have a serial output, try sending some debug information as well - like send a number for each line of your code, and the variable values, so that we can tell exactly where it stops. That's what I do if not using ICD. I have a serial VFD that I hook up just for that purpose even when not using the serial port for the program itself.

thanks for reply,

my ReceivedMsg variable is enough to store a line, max line size is 22 char,
i tried to initialise msgChar variable before while loop as a '0' value, nothing changed

gets() function really doesnt work i dont know why? my strings already have CR+LF chars at the end

and i tried to sen some numbers before each line of program and, my program stops running exactly before the while loop in readline() function.

i am using classic a usb pic programmer not a ccs-icdu