一、STM32的USART窗口通讯程序
代码:
int main(void)
{
uint8_t len=0;
uint8_t i=0;
DEBUG_UART_Config();
while(1)
{
if(USART_RX_FLAG & 0x8000)
{
len = USART_RX_FLAG & 0x3FFF;
USART_SendString(DEBUG_USARTx, "Send Message:\n");
for(i=0; i<len;i++)
{
USART_SendData(DEBUG_USARTx, USART_RX_BUF[i]);
while(USART_GetFlagStatus(DEBUG_USARTx, USART_FLAG_TC)!=SET);
}
USART_SendString(DEBUG_USARTx, "\n\n");
if(strcmp((char *)USART_RX_BUF,"stop,stm32")==0)
{
USART_SendString(DEBUG_USARTx, "stm32 Stop Send Message!");
break;
}
USART_RX_FLAG=0;
memset(USART_RX_BUF,0,sizeof(USART_RX_BUF));
}
else
{
USART_SendString(DEBUG_USARTx, "Hello windows!\n");
delay_ms(800);
}
}
}
结果:
二、C语言程序里全局变量、局部变量、堆、栈等概念,并在ubuntu和树莓派系统中分别编程,输出信息进行验证
代码:
#include <stdio.h>
#include <stdlib.h>
//定义全局变量
int init_global_a = 1;
int uninit_global_a;
static int inits_global_b = 2;
static int uninits_global_b;
void output(int a)
{
printf("hello");
printf("%d",a);
printf("\n");
}
int main( )
{
//定义局部变量
int a=2;
static int inits_local_c=2, uninits_local_c;
int init_local_d = 1;
output(a);
char *p;
char str[10] = "qwe";
//定义常量字符串
char *var1 = "1234567890";
char *var2 = "qwertyuiop";
//动态分配
int *p1=malloc(4);
int *p2=malloc(4);
//释放
free(p1);
free(p2);
printf("栈区-变量地址\n");
printf(" a:%p\n", &a);
printf(" init_local_d:%p\n", &init_local_d);
printf(" p:%p\n", &p);
printf(" str:%p\n", str);
printf("\n堆区-动态申请地址\n");
printf(" %p\n", p1);
printf(" %p\n", p2);
printf("\n全局区-全局变量和静态变量\n");
printf("\n.bss段\n");
printf("全局外部无初值 uninit_global_a:%p\n", &uninit_global_a);
printf("静态外部无初值 uninits_global_b:%p\n", &uninits_global_b);
printf("静态内部无初值 uninits_local_c:%p\n", &uninits_local_c);
printf("\n.data段\n");
printf("全局外部有初值 init_global_a:%p\n", &init_global_a);
printf("静态外部有初值 inits_global_b:%p\n", &inits_global_b);
printf("静态内部有初值 inits_local_c:%p\n", &inits_local_c);
printf("\n文字常量区\n");
printf("文字常量地址 :%p\n",var1);
printf("文字常量地址 :%p\n",var2);
printf("\n代码区\n");
printf("程序区地址 :%p\n",&main);
printf("函数地址 :%p\n",&output);
return 0;
}
在虚拟机上运行:
开发板:
树莓派: