rfid_sound.c

找的一个用U2270B开发的射频卡项目文件

// $Id: rfid_Sound.c,v 1.1 2006/09/25 22:08:15 tprescott Exp $
/*****************************************************
Project : rfid_Sound.c
Date    : 9/08/2006
Author  : Toby Prescott                   
Company : Atmel                           
Comments: AVR Studio GCC

Revisions:
	v1.0 - Started written for CodeVision 
	v2.6 - Clean for WinAVR
*****************************************************/

#include "rfid_Sound.h"

unsigned char soundState EEMEM = 1;   			// Sound On/Off flag

// *******************************************************************************
// *   Routine to create a beep using piezo element 
// *******************************************************************************
void snd_Play(unsigned char sFreq1, unsigned char sFreq0, unsigned char sTimeLength)
{
	unsigned char i,j,k;

	if(eeprom_read_byte(&soundState) == 1)						// If sound flag = on
	{
		DDRB |= 0x80;						// Set I/O to output
		for(i=0; i<sTimeLength; i++)		// Loop for beep time
		{
			PORTB &= ~0x80;                 // Turn piezo current on
			for(j=0; j<sFreq1; j++){for(k=0; k<sFreq1; k++){;}}	// Wait for sound count to reach value   
			PORTB |= 0x80;	                // Turn piezo current off
			for(j=0; j<sFreq0; j++){for(k=0; k<sFreq0; k++){;}}	// Wait for sound count to reach value
		}
		DDRB &= ~0x80;						// Set I/O to input
	}
}