LCD显示屏之前一切显示正常，有次上电之后LCD显示屏不显示应有内容。出现乱码

使用的是STM32F103C8T6最小系统版，LCD1602液晶

乱码如图：

代码如下

#include "led.h"
#include "delay.h"
#include "sys.h"
#include "key.h"
#include "usart.h"
#include "timer.h"
#include "lcd1602.h"
#include "useri2c.h"

char dis_temp[16];//ÏÔÊ¾Êý×éÔÝ´æ
char dis_temp1[16];//ÏÔÊ¾Êý×éÔÝ´æ
int dist_high = 1000;
int dist_low = 200;
u8 setFlag = 0;
u8 getFlag = 0;

//¶¨ÒåÒ»¸ö¹²Í¬Ìå£¬½á¹û¶ÁÈ¡µ½distanÊý×éÖÐ£¬distanc¾ÍÊÇ¾àÀëµÄÕûÊýÖµ£¬²»ÐèÒªÔÙÐ´³ÌÐò×ª»»
union distance_union
{
   unsigned long distance;
   unsigned int distanc;
   unsigned char distan[4];
};

int main(void)
{
   unsigned char dat[1] = {0};
   union distance_union dist;
   delay_init();       //ÑÓÊ±º¯Êý³õÊ¼»¯
   NVIC_Configuration();//ÉèÖÃNVICÖÐ¶Ï·Ö×é2:2Î»ÇÀÕ¼ÓÅÏÈ¼¶£¬2Î»ÏìÓ¦ÓÅÏÈ¼¶
   USARTx_Init(USART1,9600); //´®¿Ú³õÊ¼»¯

   UserI2c_Init();
    LED_Init();       //LED¶Ë¿Ú³õÊ¼»¯
   KEY_Init(); //°´¼ü¶Ë¿Ú³õÊ¼»¯
   TIM3_Int_Init(499,7199);//10KhzµÄ¼ÆÊýÆµÂÊ£¬¼ÆÊýµ½500Îª50ms
   Lcd_Init();   //Òº¾§³õÊ¼»¯
   delay_ms(20);
   Lcd_Puts(0,0,"Laser ranging");//ÏÔÊ¾
   delay_ms(1000);
   SensorWritenByte(dat,0x09,1);//ÉèÎª±»¶¯¶ÁÈ¡Ä£Ê½

   while(1)
   {
       if(getFlag){//500msÖÃÎ»Ò»´Î£¬¼´0.5ÃëÖ´ÐÐÒ»´Î²â¾à
           getFlag=0;//Çå³ý±êÖ¾Î»
           SensorReadnByte(dist.distan,0x02,4);//¶ÁÈ¡ÂË²¨ºó¾àÀë
       }
       KeyScan();//É¨Ãè°´¼ü
       if(KeyIsPress(key_set)){//Èç¹ûÉèÖÃ°´¼ü°´ÏÂ
           setFlag++;//ÉèÖÃ±êÖ¾Öµ¼Ó1
           setFlag%=3;//Ê¹ÉèÖÃ±êÖ¾ÖµÔÚ0~2Ö®¼ä±ä»¯£¬0Îª²»ÉèÖÃ£¬1ÎªÉèÖÃÏÂÏÞ£¬2ÎªÉèÖÃÉÏÏÞ
       }
       if(setFlag==1){//Èç¹ûµ±Ç°±êÖ¾ÊÇÉèÖÃÏÂÏÞÖµ
           if(KeyIsPress(key_dec)){//Èç¹û¡°¼õ¡±°´¼ü°´ÏÂ
               if(dist_low>20){//Èç¹ûÏÂÏÞÖµ´óÓÚ20£¨²âÁ¿¾àÀë¹ýÐ¡Ê±²»×¼È·£©
                   dist_low-=10;//ÏÂÏÞÖµµÝ¼õ10£¬µ¥Î»mm
               }
           }
           if(KeyIsPress(key_inc)){//Èç¹û¡°¼Ó¡±°´¼ü°´ÏÂ
               if(dist_low<(dist_high-10)){//Èç¹ûÏÂÏÞÖµÐ¡ÓÚÉÏÏÞ¼õ10£¨ÏÂÏÞ²»ÄÜ´óÓÚÉÏÏÞ£©
                   dist_low+=10;//ÏÂÏÞÖµµÝÔö10£¬µ¥Î»mm
               }
           }
           sprintf(dis_temp1," SL:%4d H:%4d",dist_low,dist_high);   //´òÓ¡
       }
       else if(setFlag==2){//Èç¹ûµ±Ç°±êÖ¾ÊÇÉèÖÃÉÏÏÞÖµ
           if(KeyIsPress(key_dec)){//Èç¹û¡°¼õ¡±°´¼ü°´ÏÂ
               if(dist_high>(dist_low+10)){//Èç¹ûÉÏÏÞÖµ´óÓÚÏÂÏÞ¼Ó10£¨ÏÂÏÞ²»ÄÜ´óÓÚÉÏÏÞ£©
                   dist_high-=10;//ÉÏÏÞÖµµÝ¼õ10£¬µ¥Î»mm
               }
           }
           if(KeyIsPress(key_inc)){//Èç¹û¡°¼Ó¡±°´¼ü°´ÏÂ
               if(dist_high<2000){//Èç¹ûÉÏÏÞÖµÐ¡ÓÚ2000£¨×î´ó²âÁ¿¾àÀë£©
                   dist_high+=10;//ÉÏÏÞÖµµÝÔö10£¬µ¥Î»mm
               }
           }
           sprintf(dis_temp1," L:%4d SH:%4d",dist_low,dist_high);   //´òÓ¡
       }
       else{
           sprintf(dis_temp1," L:%4d H:%4d",dist_low,dist_high);   //´òÓ¡
       }
       Lcd_Puts(0,1,dis_temp1);//ÏÔÊ¾

           if(dist.distanc>=dist_high || dist.distanc<=dist_low){//²»ÔÚãÐÖµ·¶Î§ÄÚ
               beep = 1;//·äÃùÆ÷±¨¾¯
           }
           else{
               beep = 0;//¹Ø±Õ·äÃùÆ÷
           }
           sprintf(dis_temp,"dis:%dmm ",dist.distanc);   //´òÓ¡
           Lcd_Puts(0,0,dis_temp);//ÏÔÊ¾
   }
}