直流電機：
其實直流電機也就是小的時候玩的四驅(qū)車的馬達(dá)，但是在單片機驅(qū)動是，需要家驅(qū)動電路，我至今還沒驅(qū)動起直流電機，就是因為目前不知道怎么來連接驅(qū)動電路；
控制直流電機的轉(zhuǎn)速的是用PWM波形來控制，就是控制高電平持續(xù)時間在一個周期中所占的比例，這個有個專用的名詞叫占空比來著
用單片機得到PWM波形有三種方式
方式1：利用軟件延時，當(dāng)高電平延時時間到時的時候，對I/O口電平取反，然后咋延時，當(dāng)?shù)碗娖窖訒r時間到后，在對I/O口進(jìn)行取反，如此循環(huán)就得到PWM波形
方式2：利用的是定時器延時，控制方法同上
方式3：利用單片機自帶的PWM控制器
示例代碼：得到PWM波形
//利用軟件延時：并且用鍵盤掃描得到不同的PWM
#include
#define uint unsigned int
#define uchar unsigned char
sbit PWN = P1^1;
sbit key1 = P3^1;
sbit key2 = P3^2;
uchar num;
uint yanshi;
uchar code table[]={0xc0,0xf9,0xa4,0xb0,
0x99,0x92,0x82,0xf8,
0x80,0x90,0x88,0x83,
0xc6,0xa1,0x86,0x8e};
void delayms(uint z)
{
uint x,y;
for(x = z;x>0;x--)
for(y=110;y>0;y--);
}
void main()
{
while(1)
{
P3 = 0xff;
if(key1 ==0)
{
delayms(2);
if(key1 ==0)
{
while(!key1);
num++;
if(num ==7)
{
num =0;
}
yanshi = 200*num;
}
}
switch(num)
{
case 1:
{
PWN = ~PWN;
P0 = table[num];
delayms(yanshi);
}
break;
case 2:
{
PWN = ~PWN;
P0 = table[num];
delayms(yanshi);
}
break;
case 3:
{
PWN = ~PWN;
P0 = table[num];
delayms(yanshi);
}
break;
case 4:
{
PWN = ~PWN;
P0 = table[num];
delayms(yanshi);
}
break;
case 5:
{
PWN = ~PWN;
P0 = table[num];
delayms(yanshi);
}
break;
case 6:
{
P0 = table[num];
PWN = 1;
}
break;
}
}
}
示例代碼2：
#include
#define uint unsigned int
#define uchar unsigned char
#define TIME 600
sbit led1 = P1^1;
void delay(uint xx)
{
while(xx--);
}
void main()
{
uint x;
while(1)
{
for(x = 0;x { led1 = 0; delay(TIME-x); led1 = 1; delay(x); } delay(65535); for(x=TIME;x>0;x--) { led1 = 0; delay(TIME-x); led1 = 1; delay(x); } } } 步進(jìn)電機： 步進(jìn)電機是將電脈沖信號轉(zhuǎn)變?yōu)榻俏灰坪途€位移的開環(huán)控制元件，在非超載的情況下，電機的轉(zhuǎn)速，停止的位置，只取決于脈沖信號的頻率數(shù)，和脈沖數(shù)，而不受負(fù)載變化的影響 基本的步進(jìn)電機的驅(qū)動程序： #include #define uint unsigned int main() { uint i,j; while(1) { P1 = 0x01;//0000 0001 for(i = 0;i<800;i++); P1 = 0x02;//0000 0010 for(i = 0;i<800;i++); P1 = 0x04;//0000 0100 for(i = 0;i<800;i++); P1 = 0x08;//0000 1000 for(i = 0;i<800;i++); } } 綜合程序；用按鍵實現(xiàn)步進(jìn)電機的啟動，停止，增速，減速，并在數(shù)碼管上顯示出來： #include #define uint unsigned int #define uchar unsigned char sbit dula = P2^7; sbit wela = P2^6; sbit key1 = P3^3;//這里是解決我的單片機上按鍵壞掉的問題 sbit key2 = P2^4; sbit key3 = P2^5; sbit key4 = P2^1; uchar aa,flag,speed,flag1,i;//flag 是用來標(biāo)記啟動和停止的標(biāo)志位 //flag1 是用來標(biāo)記正轉(zhuǎn)還是反轉(zhuǎn)的標(biāo)志位 uchar code table[]={0x01,0x02,0x04,0x08}; uchar code table1[]={0x3f,0x06,0x5b,0x4f, 0x66,0x6d,0x7d,0x07, 0x7f,0x6f,0x77,0x7c, 0x39,0x5e,0x79,0x71}; void init() { TMOD = 0x01; TH0 = (65536-2400)/256; TL0 = (65536-2400)%256; EA = 1; ET0 = 1; } void delay(uint z) { uint x ,y; for(x = z;x>0 ;x--) for(y = 110 ;y>0;y--); } void display1()//on顯示函數(shù) { wela = 1; P0 = 0xf7; wela = 0; P0 = 0; dula = 1; P0 = 0x3f; dula = 0; delay(5); P0 = 0xff; wela = 1; P0 = 0xef; wela =0; P0 = 0; dula = 1; P0 = 0x54; dula = 0; delay(5); } void display2()//off顯示函數(shù) { wela = 1; P0 = 0xf7; wela = 0; P0 = 0; dula = 1; P0 = 0x3f; dula = 0; delay(5); P0 = 0xff; wela = 1; P0 = 0xef; wela =0; P0 = 0; dula = 1; P0 = 0x71; dula = 0; delay(5); wela = 1; P0 = 0xdf; wela = 0; P0 = 0; dula = 1; P0 = 0x71; dula = 0; delay(5); P0 = 0xff; } void display()//顯示函數(shù) { uchar gw,sw; gw = speed%10; sw = speed/10; wela = 1; P0 = 0xfe; wela = 0; P0 = 0; dula = 1; P0 = table1[sw]; dula = 0; delay(5); P0 = 0xff; wela = 1; P0 = 0xfd; wela =0; P0 = 0; dula = 1; P0 = table1[gw]; dula = 0; delay(5); } void key_scan()//鍵盤掃描函數(shù) { P3 = 0xff; if(key2==0) { delay(5); if(key2==0) { while(!key2) {
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