DMA实验没有0-100%的动态变化为什么？

DAVIDl · 发表于 2018-6-14 22:15:42

DMA实验没有0-100%的动态变化  为什么？
我只是把原子哥的代码去掉了按键和小灯，其他的基本上一样的
这个是什么原因呢，在转换那插入500ms的延时也只有0和100两个状态，而且还是很快，求大神指点

#include "stm32f10x.h”
#include "lcd.h"
#include "delay.h"
#include "usart.h"
#include "dma.h"

#define SEND_BUF_SIZE 8200 //·￠Ëíêy¾Y3¤¶è,×îoÃμèóúsizeof(TEXT_TO_SEND)+2μÄÕûêy±¶.
u8 SendBuff[SEND_BUF_SIZE]; //·￠Ëíêy¾Y»o3åÇø
const u8 TEXT_TO_SEND[]={"ALIENTEK Elite STM32F1 DMA ′®¿úêμÑé"};

int main()
{
u16 i;
u8 t=0;
u8 j,mask=0;
float pro=0;//½ø¶è

delay_init(); //LCD±ØDëÏè3õê¼»ˉÑóê±oˉêy è»oó′®¿ú ÔùLCD  init
uart_init(115200);
LCD_Init();

POINT_COLOR=RED;
LCD_ShowString(40,50,200,24,24,"David creating!");

MYDMA_Config(DMA1_Channel4,(u32)&USART1->DR,(u32)SendBuff,SEND_BUF_SIZE); //3õê¼»ˉDMAí¨μà￡¬½«USart1μØÖ·×÷Îaíaéè»ùμØÖ·￡¬Äú»ùμØÖ·￡¬o«»o′æ′óD¡

j=sizeof(TEXT_TO_SEND);
for(i=0;i<SEND_BUF_SIZE;i++)//ìî3äêy¾Yμ½SendBuff
{
if(t>=j)//¼óèë»»DD·û
{
if(mask)
{
SendBuff[i]=0x0a;
t=0;
}else
{
SendBuff[i]=0x0d;
mask++;
}
}else//¸′ÖÆTEXT_TO_SENDóï¾ä
{
mask=0;
SendBuff[i]=TEXT_TO_SEND[t];
t++;
}
}
POINT_COLOR=BLUE;//éèÖÃ×ÖìåÎaà¶é«
i =0;
while(1)
{
LCD_ShowString(30,150,200,16,16,"Start Transimit....");
LCD_ShowString(30,170,200,16,16," %");//ÏÔê¾°ù·ÖoÅ
printf("\r\nDMA DATA:\r\n");

USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE); // USart1DMA·￠Ëí¿aÆô
MYDMA_Enable(DMA1_Channel4);
while(1)
{
if(DMA_GetFlagStatus(DMA1_FLAG_TC4)!=RESET) //»ñè¡í¨μà4±êÖ¾Î»￡¬ÅD¶ÏêÇ·ñ′«êäíê3é
{
DMA_ClearFlag(DMA1_FLAG_TC4);
break;
}
pro = DMA_GetCurrDataCounter(DMA1_Channel4); //»ñè¡ê￡óàêy¾Yá¿
pro = 1-pro/SEND_BUF_SIZE;
pro*=100; //×a»»°ù·Ö±è
LCD_ShowNum(30,170,pro,3,16);

}
// LCD_ShowNum(30,170,100,3,16);//ÏÔê¾100%
// LCD_ShowString(30,150,200,16,16,"Transimit Finished!")
}
}