rfid_userio.c

找的一个用U2270B开发的射频卡项目文件

// $Id: rfid_UserIO.c,v 1.4 2006/10/18 18:15:12 tprescott Exp $
/*****************************************************
Project : rfid_UserIO.c
Date    : 9/08/2006
Author  : Toby Prescott                   
Company : Atmel                           
Comments: AVR Studio GCC

Revisions:
	v1.0 - Started written for CodeVision 
    v2.2 - 3/8/06 Changed the I/O checking to single routine.
	v2.6 - 9/8/06 Clean for WinAVR
*****************************************************/

#include "rfid_UserIO.h"

uint8_t volatile cButton;		//Global var that stores the button currently pressed
uint8_t ioActive = 1; 	//Flag that triggers if the user I/O is checked or not
uint8_t cRelease = 1; 	//Flag that triggers if the buzzer sounds
  
uint8_t uio_Get(void)
{
	unsigned char temp, i;
	//Disable Joystick
    DDRC &= ~0x01;     	// Set Joystick Comm input 
    PORTC |= 0x01;    	// Set Joystick Comm pullup          
	
	//Enable Pushbuttons
	DDRC |= 0x02;        	// Set Function Comm output 
	PORTC &= ~0x02;      	// Set Function Comm low              
    cButton = NO_INPUT;	// Clear previous I/O read
    
	for(i=0; i<100; i++){;}		// Wait for inputs to stablize 16 * 125ns/cycle = 2us
    temp = ~PINC & 0x3C;	// Mask the inputs from the Pushbuttons
    if(temp)		// If Pushbuttons inputs present, isolate the button
    {
		if(temp == 0x04){cButton = IO_F4;}
        else if(temp == 0x08){cButton = IO_F3;}
        else if(temp == 0x10){cButton = IO_F2;}
        else if(temp == 0x20){cButton = IO_F1;}
	}
    else				// If Pushbuttons inputs not present
    {
		//Disable Pushbuttons
    	DDRC &= ~0x02;         	// Set Function Comm input 
    	PORTC |= 0x02;        	// Set Function Comm 
   
		//Enable Joystick
    	DDRC |= 0x01;        	// Set Joystick Comm output 
    	PORTC &= ~0x01;        	// Set Joystick Comm low 
	
		for(i=0; i<100; i++){;}		// Wait for inputs to stablize 16 * 125ns/cycle = 2us
    	if(!(PINE & 0x80)){cButton = IO_ENTER;}	// Check for center press
    	else
		{
			temp = ~PINC & 0x3C;	// Mask the inputs from the Joystick
	    	if(temp) 		// If Joystick inputs present, isolate the direction
	    	{
				if(temp == 0x04){cButton = IO_DOWN;}
		        else if(temp == 0x08){cButton = IO_LEFT;}
		        else if(temp == 0x10){cButton = IO_RIGHT;}
		        else if(temp == 0x20){cButton = IO_UP;}
	       	}
		} 
	}
    if(cButton && cRelease){snd_Play(BEEPFREQ1,BEEPFREQ0,BEEPTIME);}	// Audio feedback
	return cButton; 
}

void uio_Release(void)
{
    cRelease = 0;
    while(uio_Get() != 0){;}		// Wait for button release
    cRelease = 1;
}