LCD浮点数显示函数的探讨

淡淡的烟草味﹌ 2022-06-03 05:23 529阅读 0赞

单片机开放附赠的学习资料里面很少见到显示浮点数的函数，显示浮点数的操作也相当烦坠！

# 一般转换显示法 #

拿STM32单片机资源，我们选取ADC采样部分函数来看显示过程

adcx=Get_Adc_Average(ADC_Channel_5,20); LCD_ShowxNum(134,130,adcx,4,16,0); temp=(float)adcx*(3.3/4096); adcx=temp; LCD_ShowxNum(134,150,adcx,1,16,0); temp-=adcx; temp*=1000; LCD_ShowxNum(150,150,temp,3,16,0X80); LED0=!LED0; delay_ms(250);

分别取出整数部分和小数部分，分别显示出来

# 调整改进 #

void OLED_ShowFloatNum(u8 x,u8 y,double num,u8 len,u8 size)
    { 
    u32 interger=(u32)num;
    u32 fractional=(u32)((num-interger)*1000);
    u32 x_tmp;
    if(num<0)
    {
        OLED_ShowString(x,y,"Minus!",16);
    }       
    else
    {
        if(interger>=100)
        {
                x_tmp=x;
                OLED_ShowNum(x,y,interger,3,size);
        }
        else if(interger>=10&&interger<=99)
        {
            x_tmp=x-8;
            OLED_ShowNum(x,y,interger,2,size);
        }
        else if(interger>=1&&interger<=9)
        {
            x_tmp=x-16;
            OLED_ShowNum(x,y,interger,1,size);
        }
        else
        {
            x_tmp=x-16;
            OLED_ShowNum(x,y,0,1,size);
        }
    
        OLED_ShowChar(x_tmp+24,y,'.',size,1);
    
        if(fractional>=100)
            OLED_ShowNum(x_tmp+32,y,fractional,3,size);
        else if(fractional>=10&&fractional<=99)
        {
            OLED_ShowNum(x_tmp+40,y,fractional,2,size);
            OLED_ShowChar(x_tmp+32,y,'0',size,1);
        }
        else if(fractional>=1&&fractional<=9)
        {
            OLED_ShowNum(x_tmp+48,y,fractional,1,size);
            OLED_ShowChar(x_tmp+40,y,'0',size,1);
            OLED_ShowChar(x_tmp+32,y,'0',size,1);   
        }
        else
        {
            OLED_ShowChar(x_tmp+32,y,'0',size,1);
            OLED_ShowChar(x_tmp+40,y,'0',size,1);
            OLED_ShowChar(x_tmp+48,y,'0',size,1);
        }
    }
    }

# 另一种直接调用c语言函数sprintf #

定义buffer，这里注意添加头文件\#include“stdio.h”

adcx=Get_Adc_Average(ADC_Channel_0,10);
     temp=(float)adcx*(3.3/4096);
     sprintf(buffer,"%5.2f",temp);//浮点型数据转为指定格式的字符串
     LCD_ShowString(152,150,200,16,16,buffer); //直接送字符显示函数