Ganesh k
Sharing of codes regarding different interfacing of electronics modules.
GSM Interfacing
#include "mbed.h"
#include <pic18f4550.h>
#include "Configuration_Header_File.h"
#include "LCD_16x2_8-bit_Header_File.h"
#include "USART_Header_File.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
void GSM_Init();
void GSM_Calling(char *);
void GSM_HangCall();
void GSM_Response();
void GSM_Response_Display();
void GSM_Msg_Read(int);
int GSM_Wait_for_Msg();
void GSM_Msg_Display();
void GSM_Msg_Delete(unsigned int);
void GSM_Send_Msg(const char* , const char*);
char buff[160]; /* buffer to store responses and messages */
volatile char status_flag; /* monitor to check for any new message */
volatile int a;
unsigned int mobile_no[14];
unsigned char msg_received[60];
unsigned int position=0;
void main(void)
{
a=0;
int is_message_arrived=0;
OSCCON =0x72; /* set internal oscillator Freq = 8 MHz*/
LCD_Init(); /* initialize LCD */
INTCONbits.GIE=1; /* enable Global Interrupt */
INTCONbits.PEIE=1; /* enable Peripheral Interrupt */
PIE1bits.RCIE=1; /* enable Receive Interrupt */
MSdelay(100);
USART_Init(9600); /* initialize USART communication */
GSM_Init(); /* check GSM responses and initialize GSM */
// LCD_Clear();
// LCD_String("Sending SMS...");
// MSdelay(3000);
////
// GSM_Send_Msg("8007332284","TEST"); /*send sms on "mobile no."*/
// MSdelay(3000);
LCD_Clear();
while(1)
{
LCD_Clear();
/* waiting for message to receive */
LCD_String_xy(0,0,"waiting for msg");
// status_flag=0;
if(status_flag==1)
{
LCD_Clear();
// LCD_String_xy(0,0,"New msg arrive");
// MSdelay(1000);
// LCD_Clear();
is_message_arrived = GSM_Wait_for_Msg(); /*wait for new message to read */
if(is_message_arrived==1)
{
LCD_String_xy(0,0,"New msg arrive");
GSM_Msg_Read(position);
}
MSdelay(3000);
is_message_arrived==0;
status_flag = 0;
}
MSdelay(1000);
}
// while(1);
}
void GSM_Init()
{
while(1)
{
LCD_Command(0xc0);
USART_SendString("ATE0\r"); /* send AT to check module is ready or not*/
MSdelay(500);
if(strstr(buff,"OK"))
{
GSM_Response(); /* find response and display it on LCD16x2 */
memset(buff,0,160);
break;
}
else
{
LCD_String("Error");
}
}
MSdelay(2000);
LCD_Clear();
LCD_String_xy(0,0,"Text Mode");
LCD_Command(0xc0);
USART_SendString("AT+CMGF=1\r");/* select message format as text */
GSM_Response();
MSdelay(2000);
LCD_Clear();
LCD_String_xy(0,0,"Mfd name");
LCD_Command(0xc0);
USART_SendString("AT+GMI\r"); /* identify manufacturer */
GSM_Response();
MSdelay(2000);
LCD_Clear();
LCD_String_xy(0,0," Model No.");
LCD_Command(0xc0);
USART_SendString("AT+GMM\r"); /* find model no. */
GSM_Response();
MSdelay(2000);
LCD_Clear();
LCD_String_xy(0,0," IMEI No. ");
LCD_Command(0xc0);
USART_SendString("AT+GSN\r"); /* find IMEI no. of module */
GSM_Response();
MSdelay(2000);
LCD_Clear();
LCD_String_xy(0,0,"Service Provider");
MSdelay(1000);
LCD_Clear();
LCD_Command(0xc0);
USART_SendString("AT+CSPN?\r"); /* find service provider name */
GSM_Response();
MSdelay(2000);
}
void GSM_Msg_Delete(unsigned int position)
{
a=0;
char delete_cmd[20];
sprintf(delete_cmd,"AT+CMGD=%d\r",position); /* delete message at specified position */
USART_SendString(delete_cmd);
MSdelay(100);
memset(buff,0,strlen(buff));
}
int GSM_Wait_for_Msg()
{
char i,val[4];
LCD_Clear();
a=0;
while(1)
{
if(buff[a]==0x0d || buff[a]==0x0a) /*eliminate "\r \n" which is start of string */
{
a++;
}
else
break;
}
if(strstr(buff,"CMTI:")) /* check if any new message received */
{
while(buff[a]!=',')
{
a++;
}
a++;
// LCD_Command(0x80);
// LCD_String("Position: "); /* display position of message received */
i=0;
while(buff[a]!=0x0d)
{
val[i]=buff[a];
// LCD_Char(buff[a]); /* display position of new message where it is stored */
a++;
i++;
}
position = atoi(val);
if(position>20)
{
LCD_String_xy(0,0,"Msg mem full");
memset(buff,0,strlen(buff));
return 2;
}
memset(buff,0,strlen(buff));
a=0;
return 1;
// GSM_Msg_Read(position); /* read message which is recently arrived from position */
}
else
{
return 0;
}
// status_flag = 0;
}
void interrupt ISR()
{
if(RCIF)
{
buff[a] = RCREG; /* read received byte from serial buffer */
a++;
if(RCSTAbits.OERR) /* check if any overrun occur due to continuous reception */
{
CREN = 0;
NOP();
CREN=1;
}
status_flag=1; /* use for new message arrival */
}
}
void GSM_Send_Msg(const char *num,const char *sms)
{
int i;
char sms_buffer[35];
a=0;
sprintf(sms_buffer,"AT+CMGS=\"%s\"\r",num);
USART_SendString(sms_buffer); /*send command AT+CMGS="Mobile No."\r */
MSdelay(200);
while(1)
{
if(buff[a]==0x3e) /* wait for '>' character*/
{
a=0;
memset(buff,0,strlen(buff));
USART_SendString(sms); /* send msg to given no. */
USART_TxChar(0x1a); /* send Ctrl+Z then only message will transmit*/
break;
}
a++;
}
MSdelay(300);
a=0;
memset(buff,0,strlen(buff));
memset(sms_buffer,0,strlen(sms_buffer));
}
void GSM_Calling(char *mobile)
{
char call[20];
sprintf(call,"ATD%s;\r",mobile); /* send command ATD8007xxxxxx; for calling*/
USART_SendString(call);
}
void GSM_HangCall()
{
USART_SendString("ATH\r"); /*send command ATH\r to hang call*/
}
//void GSM_Response()
//{
// unsigned int timeout=0;
// int CRLF_Found=0;
// char CRLF_buff[2];
// int Response_Length=0;
// while(1)
// {
// if(timeout>=60000) /*if timeout occur then return */
// return;
// Response_Length = strlen(buff);
// if(Response_Length)
// {
// MSdelay(1);
// timeout++;
// if(Response_Length==strlen(buff))
// {
// for(int i=0;i<Response_Length;i++)
// {
// memmove(CRLF_buff,CRLF_buff+1,1);
// CRLF_buff[1]=buff[i];
// if(strncmp(CRLF_buff,"\r\n",2))
// {
// if(CRLF_Found++==2) /* search for \r\n in string */
// {
// GSM_Response_Display();
// return;
// }
// }
//
// }
// CRLF_Found =0;
//
// }
//
// }
// MSdelay(1);
// timeout++;
// }
//}
void GSM_Response(){
unsigned int timeout=0;
int Response_Length=0;
// while(1){
// if(timeout>=60000) /*if timeout occur then return */
// return;
// Response_Length
MSdelay(500);
GSM_Response_Display();
// }
}
void GSM_Response_Display()
{
a=0;
int lcd_pointer=0;
while(1)
{
if(buff[a]==0x0d || buff[a]==0x0a)
{
a++;
}
else
break;
}
LCD_String_xy(1,0," ");
LCD_Command(0xc0);
while(buff[a]!=0x0d)
{
LCD_Char(buff[a]);
a++;
lcd_pointer++;
if(lcd_pointer==15)
LCD_Command(0x80);
}
a=0;
memset(buff,0,strlen(buff));
}
void GSM_Msg_Read(int position)
{
int i,k;
char flag,read_cmd[10];
i=0;
sprintf(read_cmd,"AT+CMGR=%d\r",position);
USART_SendString(read_cmd);
MSdelay(1000);
GSM_Msg_Display();
}
void GSM_Msg_Display()
{
unsigned int m=0;
if(!(strstr(buff,"+CMGR"))) /*check for +CMGR response */
{
LCD_String_xy(0,0,"No message");
}
else
{
a=0;
while(1)
{
if(buff[a]==0x0d || buff[a]==0x0a) /*wait till \r\n not over*/
{
a++;
}
else
break;
}
// while(buff[a]!=0x3a) /*wait till string not equal to ':' */
// {
// a++;
// }
while(buff[a]!=',')
{
a++;
}
a=a+2;
while(buff[a]!=0x22)
{
mobile_no[m] = buff[a];
m++;
}
do
{
a++;
}while(buff[a-1]!=0x0a);
LCD_Command(0xC0);
int i=0;
while(buff[a]!=0x0d && i<31)
{
msg_received[i]=buff[a];
LCD_Char(buff[a]);
a++;
i++;
if(i==16) /* if received message is greater than 16(for display message)*/
LCD_Command(0x80); /* resume display of message from 1st line */
}
a=0;
memset(buff,0,strlen(buff));
}
status_flag = 0;
}
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