單片機輸出PWM波.doc

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1、單片機輸出PWM波//*******************函數(shù)聲明，變量定義*******************#include#include#defineucharunsignedchar#defineuintunsignedint//端口定義sfrp0=0x80;sfrp1=0x90;sfrp2=0xa0;sfrp3=0xb0;//鍵sbitadd_speed=P1^0;sbitsub_speed=P1^1;//PWM控速uinttime_PWM=0;??//PWM時間計數(shù)uinthigh_PWM=0;??//

2、PWM高電平時間uintt_PWM=16;??//PWM周期//*******************延時??程序*******************voiddelayms(unsignedcharms){??unsignedchari;??while(ms--)??{????for(i=0;i<120;i++);??}}//*******************鍵盤掃描程序*******************voidkey_change(){??if(add_speed==0)??{????delayms(10);????if(add_speed==0)

3、????{????????if(high_PWM<16)????????{??????????high_PWM++;????????}}?}??if(sub_speed==0)??{????delayms(10);????if(sub_speed==0)????{????????if(high_PWM>0)????????{??????????high_PWM--;????????}}?}}//*******************中斷程序*******************//PWM波生成，T0中斷voidPWM_T0(void)interrupt1{??

4、TH0=0Xd8;??????????????TL0=0Xf0;??????????????time_PWM++;??if(time_PWM

5、0=0xd8;??//定時10usTL0=0xf0;TMOD=0x01;EA=1;ET0=1;TR0=1;while(1){???key_change();}}