Use 89S51 stand-alone P1^0 to output 1KHZ and 500HZ audio signals. 1KHZ signal is required to sound for 100ms, 500HZ signal is required to sound for 200ms alternately. P1^7 is connected to a switch for control. When the switch is closed, the alarm signal sounds. When the switch is open, the alarm stops. Write the program as follows
Keywords：89S51
Reference address：Use 89S51 single chip microcomputer P1^0 to output 1KHZ and 500HZ audio signals
#include
#define uchar unsigned char
sbit K =P1^7；
sbit out =P1^0；
void main ( )
{while ( 1)
{if (K ==0)
uchar i ；
for (i =200；i ＞0；i --)
{m _500HZ ( )；
}
for (i =200；i ＞0；i --)
{m _1KHZ ( )；
}
}
}
}
void m _500HZ ( )
{out =~out
delay (2)；
}
void m _1KHZ ( )
{out =~out
delay (1)
}
void delay (uchar z )
{uchar x ；
uchar y ；
for (x =z；x ＞0；x --)
{for (y =55；y ＞0；y --)
}
}
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