speaker.c

音响效果程序

#include <reg52.h>
#define SpeakerBit	0xdf
void SpeakerOpen( void ){ P2 &= SpeakerBit; }
void SpeakerClose( void ){ P2 |= SpeakerBit^0xff; }

void Midi( unsigned char sound, unsigned char time )			//一个工程项目必须有一个main函数,并且只能有一个main函数
{
	char loop;
	code unsigned int pn[]={	8*105,
						4*200, 4*178, 4*159, 4*150, 4*133, 4*118, 4*105,
						2*200, 2*178, 2*159, 2*150, 2*133, 2*118, 2*105,
						1*200, 1*178, 1*159, 1*150, 1*133, 1*118, 1*105, 100};

	for( loop=0; loop<time; ++loop)
	{
		unsigned int lp, len;
		len = 30000/pn[sound];
		for( lp=0; lp<len; lp++ )
		{
			unsigned int nlp;
			SpeakerOpen();
			for(nlp=pn[sound]; nlp>0; --nlp );
			SpeakerClose();
			for(nlp=pn[sound]; nlp>0; --nlp );
		}
	}
}