sim808 freezes after one SMS using stm32 - arm

Question

I am trying to design a GPS car tracker with a SIM808 module using a STM32F103RET6 header board and I want to get the location link messaged to my phone by sending an SMS to the module. Right now my code works but only when I reset the board after sending each SMS. I attached my code can you figure out what is the problem?
main code :
#include <stm32f10x.h>
#include "usart.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
char S=0x1A;
#define Enter usart_sendchar('\n');
#define CR usart_sendchar('\r');
#define GIM usart_sendchar('"');
#define SUB usart_sendchar(S);
#include "stm32f10x.h"
#include <string.h>
char get_Enter = 0;
uint8_t ch;
char str1[300];
char str2[100];
int i=0;
char flag=0;
char str_tmp[20];
char str_tmp2[20];
char* p;
volatile uint32_t msTicks;
//calling all the functions
void Send_SMS(char *text);
void CMTI(void);
void wait_to_get(char ch);
void del_All_SMS(void);
void CMGF_1(void);
void Delay (uint32_t Time);
void CMGR (void);
void CGNSPWR_1(void);
void CGNSINF(void);
void interrupt_activation(void);
void CGNSINF_C(void);
void AT(void);
void Delay (uint32_t dlyTicks);
void SysTick_Handler(void);
// the interrupt handler for the systick module
void SysTick_Handler(void) {
msTicks++;
}
void Delay (uint32_t dlyTicks) {
uint32_t curTicks;
curTicks = msTicks;
while ((msTicks - curTicks)< dlyTicks);
}
void Send_SMS(char *text)
{
CMGF_1();
Delay(500);
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"AT+CMGS=");
Delay(500);
usart_sendstring(str_tmp);
GIM
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"+98905xxxxxxx");
Delay(500);
usart_sendstring(str_tmp);
GIM
Enter
CR
Delay(500);
usart_sendstring(text);
Enter
CR
str_tmp[0]='\0';
Delay(500);
SUB
Delay(100);
del_All_SMS();
}
void USART1_IRQHandler(void) {
ch = USART1->DR & 0xFF;
if (ch == '\n'){ // 13 enter
get_Enter =1;
}
else{
str1[i]= ch;
i++;
}
}
void CMGF_1(void)
{
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"AT+CMGF=1");
Delay(500);
usart_sendstring(str_tmp);
Enter
CR
}
void del_All_SMS(void)
{
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"AT+CMGD=1,4");
Delay(500);
usart_sendstring(str_tmp);
Enter
CR
}
void CMGR(void)
{
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"AT+CMGR=1");
Delay(500);
usart_sendstring(str_tmp);
Enter
CR
}
void CGNSINF(void)
{
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"AT+CGNSINF");
Delay(500);
usart_sendstring(str_tmp);
Enter
CR
}
void CGNSPWR_1(void)
{
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"AT+CGNSPWR=1");
Delay(500);
usart_sendstring(str_tmp);
Enter
CR
}
void AT(void)
{
str_tmp[0]='\0';
Delay(100);
strcpy(str_tmp,"AT");
Delay(500);
usart_sendstring(str_tmp);
Enter
CR
}
int main()
{
SystemInit();
SysTick_Config(SystemCoreClock/1000); // setup systick timer for 1ms interrupts
usart_init();
AT();
p=NULL;
check:AT();
Delay(2000);
p=strstr(str1,"OK");
if(p==NULL) goto check;
CMGF_1();
Delay(500);
CGNSPWR_1();
Delay(500);
del_All_SMS();
Delay(500);
RCC->APB2ENR |= (1<<3);
GPIOB->CRL &= ~0xF;
GPIOB->CRL |= 0x3;
while (1)
{
if (get_Enter ==1)
{
if (flag==0){
////waiting for +CMTI: from sim800
do
{
p=strstr(str1,"+CMTI:");
}
while(p==NULL);
Delay(1000);
// sending AT+CMGR=1 command
if (p!=NULL)
{
CMGR();
Delay(350);
flag=1;
}
}
if (flag==1) {
p=strstr(str1,"+CMGR");
if (p){
p=strstr(str1,"loc");
if (p!=NULL)
{
CGNSINF();
Delay(300);
}
else if (p==NULL)
{
del_All_SMS();
memset(str1, 0, 300);
flag=0;
}
p=strstr(str1,"+CGNSINF:");
if (p)
{
float a[5];
char str2[80];
const char s[2] = ",";
char *token;
// getting the lattitude and longitude
token = strtok(p, s);
for (int i=0;i<5;i++){
sprintf( str2," %s\n", token );
a[i]=atof(str2);
token = strtok(NULL, s);
}
sprintf(str2,"https://maps.google.com/?q=%.6f,%.6f",a[3],a[4]);
Send_SMS(str2);
p=NULL;
del_All_SMS();
flag=0;
memset(str1, 0, 300);
}
}
}
}
}
}
usart code :
#include "stm32f10x.h"
#include "usart.h"
char str[200];
char data;
//// initialize usart
void usart_init(void)
{
RCC->APB2ENR |= ( 1UL << 0); /* enable clock Alternate Function */
AFIO->MAPR &= ~( 1UL << 2); /* clear USART1 remap */
RCC->APB2ENR |= ( 1UL << 2); /* enable GPIOA clock */
GPIOA->CRH &= ~(0xFFUL << 4); /* clear PA9, PA10 */
GPIOA->CRH |= (0x0BUL << 4); /* USART1 Tx (PA9) output push-pull */
GPIOA->CRH |= (0x04UL << 8); /* USART1 Rx (PA10) input floating */
RCC->APB2ENR |= ( 1UL << 14); /* enable USART#1 clock */
USART1->BRR=0x1D4C; // 9600 #72MHz
// USART1->BRR = 0x0271; /* 115200 baud # PCLK2 72MHz */
USART1->CR1 = (( 1UL << 2) | /* enable RX */
( 1UL << 3) | /* enable TX */
( 0UL << 12) ); /* 1 start bit, 8 data bits */
USART1->CR2 = 0x0000; /* 1 stop bit */
USART1->CR3 = 0x0000; /* no flow control */
USART1->CR1 |= ( 1 << 13); /* enable USART */
USART1->CR1 |= ( 1UL << 5); // RXNE interrupt enable
NVIC_SetPriority(USART1_IRQn,5); /* Default priority group 0, can be 0(highest) - 31(lowest) */
NVIC_EnableIRQ(USART1_IRQn); /* Enable UART0 Interrupt */
}
void usart_sendchar(char data){
while(!(USART1->SR&(1<<7)));
USART1->DR=data;
}
char usart_getchar(void)
{
while (!(USART1->SR&(1<<5)));
data=USART1->DR ;
return data;
}
void usart_getstring(char *str)
{
char *temp = str;
do{
*temp = usart_getchar();
usart_sendchar (*temp) ;
} while(*(temp++) != 0x0D );
*(temp-1) = 0;
}
void usart_sendstring(char *s)
{
while (*s)
{
usart_sendchar(*s);
s++;
}
}