Receive string on PIC18F452 UART

[Swys]

pic18f452 uart

Hi all,

I was wondering if anyone could help me on this. I am working on MPLAB with a PIC18F452 and the HI-TECH compiler. I want to write a function which must be able to receive a string of characters from the UART. I enter this string on my terminal program.

I am able to receive a single character, but i want to receive a whole string of characters.

//Receive one character
unsigned char getch()
{
	while (!RCIF)
		continue;
	
	return RCREG;
}

//Input a series of characters into the specified buffer
//NOT WORKING!!!
void gets(char *s)
{
	char c = 0;
	
	while (c != '\0')
	{
		c = getch();
		*s = c;
		*s++;
	}	
}

I've been struggeling with this for a while now. If anyone can help I would greatly appreciate it!

 

[saeed_pk]

pic18f452 usart

I am sending you exact files

usart.c and usart.h use in your program

it have a function receive string

it receives string terminated by NULL

I hope this will help you.
you can change return type from void to 'const char *'

 

[Fayyaz Hussain]

Re: pic18f452 usart

I am sending you exact files

usart.c and usart.h use in your program

it have a function receive string

it receives string terminated by NULL

I hope this will help you.
you can change return type from void to 'const char *'

Dear
I am doing Final year project about GSM and i have much problem to reading and displaying my data on LCD
basically i have problem with UART
how i can read my complete data from UART and display on LCD
and i am using MikroC v6 compiler
Plz guide me
my code is:

#include <built_in.h>
unsigned char i;
unsigned char Byte[30];
sbit LCD_RS at RB0_bit;
sbit LCD_EN at RB1_bit;

sbit LCD_D4 at RB4_bit;
sbit LCD_D5 at RB5_bit;
sbit LCD_D6 at RB6_bit;
sbit LCD_D7 at RB7_bit;

sbit LCD_RS_Direction at TRISB0_bit;
sbit LCD_EN_Direction at TRISB1_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;
void main()
{
TRISB=0X00;
PORTB=0X00;

UART1_init(9600);

Lcd_Init();
while(1)
{
Lcd_Cmd(_LCD_CURSOR_OFF);
Lcd_Cmd(_LCD_CLEAR);
Lcd_Out(1,1,"PROJECT OF");
Lcd_Out(2,1,"MSc ELT");
Delay_ms(2000);
Lcd_Cmd(_LCD_CLEAR);
Lcd_Out(1,1,"MTU");
Delay_ms(500);
TXSTA = 0X20;
UART1_write_Text("AT\r");
Delay_ms(200);
UART1_write_Text("AT+CMGF=1\r");
Delay_ms(200);
Lcd_Cmd(_LCD_CLEAR);
Lcd_Out(1,1,"RAEDING RTU DATA");
Lcd_Out(2,1,"WAITING....");
UART1_write_Text("AT+CMGR=1\r");
CREN = 0X10;
while (UART1_Data_Ready() == 1) //problem is how UART will read the data transmited by GSM
{
Byte = UART1_Read();
Lcd_Out(2,1,Byte);
i++;
}
Delay_ms(500);
//UART1_write_Text("AT+CMGD=1\r");

Delay_ms(500);
Lcd_Cmd(_LCD_CLEAR);
Lcd_Out(1,2,"RTU DATA READ");
Delay_ms(10000);
}
}

 

[nick703]

try to put some delay after UART1_init(9600) function and remove

while (UART1_Data_Ready() == 1) //problem is how UART will read the data transmited by GSM
this to like
if((UART1_Data_Ready())

and also reply .

 

[themask]

Re: pic18f452 uart

void gets(char *s)
{
	char c = 0;
	
	while (c != '\0')
	{
		c = getch();
		*s = c;
		*s++;              //<---- WRONG
	}	
}

it should be

s++;

since you want the pointer to point to the next character position in the string, and not increment the value.

Review your C pointer operations in the meantime.