#include "mc8051fun.h"


static uint8_t lastb=0xff;
static uint8_t hist=0x00;

int8_t rotary_encoder_stat(uint8_t b)
{
	if (b==0x00)
		return 0;
	if (b==lastb)
		return 0;

	lastb=b;
	hist = (hist << 2) | b;
	switch (hist){
		case 0b11011011:
			return 1;
		case 0b11100111:
			return -1;
		default:
			return 0;
	}

}