[51] GSM module"SIM 300" interfacing with 8051 in C language

[asoni14593]

Hi,
I am making a project related to GSM module in which i just want to send message but the error i am facing is how i connect that modem to microcontroller and how i get the output of GSM module on LCD 1602.
i.e. Firstly When i send AT command to the GSM modem how i get OK on my LCD .
Waiting for the Best Reply.
Thank you

 

[sudheer kumar]

As SIM300 works with UART protocol, use UART TX to send commands.Then what ever GSM replies read with UART RX and display the same on LCD.
smaple code:

tx_string("AT");
x=RX();
LCD_dat(x);

 

[asoni14593]

Hi,
Sir here it is my whole code.
i did as per ur advise.

firstly it gives an error that

"MAIN.C(38): error C214: illegal pointer conversion"

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Code C - [expand]
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#include<reg51.h>
#include<string.h>
sfr LCD=0xA0; //LCD on Port 2
sbit RS=P0^4;
sbit EN=P0^5;
sbit RW=P0^6;
int i;
void delay(int msec);
void LCD_CMD(unsigned char cmd);
void LCD_alpha(unsigned char alpha);
void LCD_string(unsigned char *string);
void LCD_init();
void Ser_init();
void Ser_TX(unsigned char *msg);
void alpha_sent(unsigned char alph);
 
void main()
{
LCD_init();  
Ser_init();
LCD_string("Serial Port Initialisation DONE!!");
IE=0x92;
Ser_TX("AT");
delay(10);
LCD_alpha(0x0D);   //For Carrier return
delay(50);
}
 
 
void Ser_RX() interrupt 4    //receive msg from GSM module
{
unsigned char rec_msg;
int l_msg;
while(1)
{
while(RI==0);
rec_msg=SBUF; 
l_msg=strlen(rec_msg);      //error generate here
for(i=0;i<l_msg;i++)
{
alpha_sent(rec_msg[i]);
delay(50);
}
RI=0;
}
}
 
void alpha_sent(unsigned char alph) //Send an alphabet to GSM module
{
SBUF=alph;
while(TI==0);
TI=0;
}
 
void Ser_TX(unsigned char *msg) //Send String to GSM module
{
int len_msg;
len_msg=strlen(msg);
for(i=0;i<len_msg;i++)
{
alpha_sent(msg[i]);
delay(50);
}
}
 
void Ser_init()       //serial port initialised
{
TMOD=0x20;
TH1=0xFD;
SCON=0x50;
TR1=1;
}
 
void LCD_init()       //lcd initialised
{
LCD_cmd(0x38);
LCD_cmd(0x0E);
LCD_cmd(0x01);
LCD_cmd(0x06);
LCD_string("LCD initialisation Done!!");
}
 
void LCD_string(unsigned char *string) //Send a string to LCD
{
int len;
len=strlen(string);
for(i=0;i<len;i++)
{
LCD_alpha(string[i]);
delay(100);
}
}
void LCD_alpha(unsigned char alpha) //Send an alphabet to LCD
{
RW=0;
LCD=alpha;
EN=1;
RS=1;
delay(5);
EN=0;
}
 
void LCD_CMD(unsigned char cmd) //Send Commands to drive LCD
{
RW=0;
LCD=cmd;
EN=1;
RS=0; 
delay(5);
EN=0;
}
 
void delay(int msec) 
{
int j;
for(i=0;i<msec;i++)
{
for(j=0;j<125;j++)
{
}
}
}

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Thank You For your Last REPLY it was helpfull.
waiting for your next reply sir..