test.c

AT89C51+MAX7221实现4*4键盘扫描

#include "Max7221.h"


void main(void)
{
	unsigned char DisplayBuffer[8];
	int i;
	unsigned char KeyID;
	InitialMax7221();

while(1)
{
	P2= 0xF0;
	while(1)
	{
		if(P2 != 0xF0)
		{
			KeyID = 0x0F & P2;
			break;
		}
	}
	
	P2 = 0x0F;
	KeyID = KeyID + 0xF0 & P2;

	for(i=0; i <8; i++)
	{
		DisplayBuffer[7-i]= KeyID % 16;
		KeyID = KeyID / 16;
	}

	Max7221Display(DisplayBuffer);

}
}