現在電子式電度表很便宜，買了一個測量電動車的充電量，以此估算電池性能。
為方便觀察充電時間和充電功率，本人用STC15W408AS做了一個計時計數器。利用光敏二極管將電度表的閃燈信號轉化為電脈沖信號，經單片機計算處理后，用一個4位數碼管輪流顯示充電度數、每閃功率和充電時長。程序見附件。
單片機源程序如下:
- #define MAIN_Fosc 12000000 //定義主時鐘
- //#include<reg52.h>
- #include "STC15Fxxxx.H"
- #define uchar unsigned char
- #define uint unsigned int
- sbit COUNT_IN=P3^2;
- unsigned code table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};
- #define DataPort P1;
- sbit led1=P3^4;
- sbit led2=P3^5;
- sbit led3=P3^6;
- sbit led4=P3^7;
- unsigned long count; //max 4294967295*.000625Kwh=2684354Kws
- unsigned long kwh; //max 4294967295*.000625Kwh=2684354Kws
- unsigned int t0,t1,w0,w,s10; //t0,t1 max 65535*.05=3276s, w max 45000w, s10 max 65535*10s/3600s=182h,7.58day
- unsigned char h; //max 65535*10s/3600s=182h,7.58day
- bit flag;
- void init()
- {
- IT0=1; //INT0負跳變觸發
- TMOD=0x01;//定時器工作于方式1
- TH0=0x3c; //50ms 12Mhz
- TL0=0xb0;
- EA=1; //CPU開中斷總允許
- ET0=1;//開定時中斷
- EX0=1;//開外部INTO中斷
- TR0=1;//啟動定時
- }
- //========================================================================
- // 函數: void Delayms(unsigned int ms)
- // 描述: STC15延時函數。
- // 參數: ms,要延時的ms數, 這里只支持1~65535ms. 自動適應主時鐘.
- // 返回: none.
- // 版本: VER1.0
- // 日期: 2013-4-1
- // 備注:
- //========================================================================
- void Delayms(unsigned int ms)
- {
- unsigned int i;
- do{
- i = MAIN_Fosc / 13000;
- while(--i) ; //14T per loop
- }while(--ms);
- }
- //**********************************************
- void EXINT0() interrupt 0
- {
- // kwh=kwh+.000625;
- count++; //累計電度表輸出脈沖個數
- w0=45000/t1; //每閃功率瓦數 w=.625*3600*20/t1(50毫秒數)
- t1=0; //每閃時長清0
- }
- void time0() interrupt 1
- {
- TH0=0x3c;
- TL0=0xb0; //50ms,STC15W408AS內部時鐘，12Mhz
- t0++; //累計時長
- t1++; //每閃時長
- if(t0>199) //10s 200*.05s=10s
- {
- t0=0;
- s10=s10+1; //max 65535*10s/3600s=182h,7.58day
- }
- if(t1>65534) //max 65534*.05=3276s
- {
- t1=65534;
- }
- }
- void display_SMG_kwh(void)
- {
- P1=table[kwh/1000];
- led1= 0;
- Delayms(5);
- led1 = 1;
- P1=table[kwh%1000/100]&0x7f;
- led2 = 0;
- Delayms(5);
- led2 = 1;
- P1=table[kwh%100/10];
- led3 = 0;
- Delayms(5);
- led3 = 1;
- P1=table[kwh%10];
- led4 = 0;
- Delayms(5);
- led4 = 1;
- }
- void display_SMG_w(void)
- {
- P1=table[w%10000/1000];
- led1= 0;
- Delayms(5);
- led1 = 1;
- P1=(table[w%1000/100]);
- led2 = 0;
- Delayms(5);
- led2 = 1;
- P1=table[w%100/10];
- led3 = 0;
- Delayms(5);
- led3 = 1;
- P1=table[w%10];
- led4 = 0;
- Delayms(5);
- led4 = 1;
- }
- void display_SMG_h(void)
- {
- P1=0x8b;
- // P1=table[h/1000];
- led1= 0;
- Delayms(5);
- led1 = 1;
- P1=table[h%1000/100];
- led2 = 0;
- Delayms(5);
- led2 = 1;
- P1=table[h%100/10]&0x7f;
- led3 = 0;
- Delayms(5);
- led3 = 1;
- P1=table[h%10];
- led4 = 0;
- Delayms(5);
- led4 = 1;
- }
- void main()
- {
- unsigned char a;
- init();
- while(1)
- {
- for(a=0;a<=50;a++)
- {
- kwh=count*.0625; //用電度數=電度表閃燈次數*.000625kwh*100，(2位小數)
- display_SMG_kwh();
- }
- for(a=0;a<=50;a++)
- {
- // w=kwh*1000*3600/s10; //用電瓦數=累計千瓦時*1000*3600/累計秒數
- w=w0;
- display_SMG_w();
- }
- for(a=0;a<=50;a++)
- {
- h=s10/360; //用電小時數=累計秒數/3600*10,(1位小數)
- display_SMG_h();
- }
- }
- }
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