main.c

一个红外分析仪的固件程序。使用的AVRUSB硬件（ATMEGA8）。

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <avr/wdt.h>
#include <util/delay.h>     /* for _delay_ms() */

#include "oddebug.h"        /* This is also an example for using debug macros */

#include "usbdrv.h"

#define	SET_LED_RED			1
#define SET_LED_GREEN		2
#define GET_DATA		3
#define START		4

#define Set_Bit(val, bitn)     (val |=(1<<(bitn))) 
#define Clr_Bit(val, bitn)     (val&=~(1<<(bitn))) 
#define Get_Bit(val, bitn)     (val &(1<<(bitn)) )
#define Rsv_Bit(val, bitn)     (val ^=(1<<(bitn)))

#define ledGreenOn()  PORTD &= ~(1 << PD3)
#define ledGreenOff() PORTD |= (1 << PD3)
#define ledGreenRsv()   PORTD ^= (1 << PD3)
#define ledRedOn()    PORTD &= ~(1 << PD4)
#define ledRedOff()   PORTD |= (1 << PD4)
#define ledRedRsv()   PORTD ^= (1 << PD4)

#define IRBUFSIZE	100

uchar start,prt,last;
uchar irbuf[IRBUFSIZE];

PROGMEM char usbDescriptorConfiguration[25] = {    /* USB configuration descriptor */
    9,          /* sizeof(usbDescriptorConfiguration): length of descriptor in bytes */
    USBDESCR_CONFIG,    /* descriptor type */
    18 + 7, 0,
                /* total length of data returned (including inlined descriptors) */
    1,          /* number of interfaces in this configuration */
    1,          /* index of this configuration */
    0,          /* configuration name string index */
    (char)USBATTR_BUSPOWER, /* attributes */
    USB_CFG_MAX_BUS_POWER/2,            /* max USB current in 2mA units */
	
	/* interface descriptor follows inline: */
    9,          /* sizeof(usbDescrInterface): length of descriptor in bytes */
    USBDESCR_INTERFACE, /* descriptor type */
    0,          /* index of this interface */
    0,          /* alternate setting for this interface */
    2, /* endpoints excl 0: number of endpoint descriptors to follow */
    USB_CFG_INTERFACE_CLASS,
    USB_CFG_INTERFACE_SUBCLASS,
    USB_CFG_INTERFACE_PROTOCOL,
    0,          /* string index for interface */

	/* endpoint descriptor for endpoint 1 */
    7,          /* sizeof(usbDescrEndpoint) */
    USBDESCR_ENDPOINT,  /* descriptor type = endpoint */
    (char)0x81, /* IN endpoint number 1 */
    0x03,       /* attrib: Interrupt endpoint */
    8, 0,       /* maximum packet size */
    USB_CFG_INTR_POLL_INTERVAL, /* in ms */

};


unsigned char usbFunctionSetup(unsigned char data[8])
{
	uchar len = 0;
	usbRequest_t *rq = (void *)data;
	switch(rq->bRequest)
	{
	case SET_LED_RED:
		if(rq->wValue.bytes[0]==0)
			ledRedOff();
		else
			ledRedOn();
		break;
	case SET_LED_GREEN:
		if(rq->wValue.bytes[0]==0)
			ledGreenOff();
		else
			ledGreenOn();
		break;
	case START:
		start=rq->wValue.bytes[0];
		if(start)
		{
			ledRedOn();
		prt=0;
		last=1<<(PC2);
		}
		else ledRedOff();
		break;
	case GET_DATA:
		len=0xff;
		ledRedRsv();
 		break;      

	default:
		break;		  			  			  			  			  		  			   
	}
	return len;
}

//==================================================
//定时器T0初始化
void timer0_init(void)
{
	TCCR0  = 0x00;//停止定时器
	TCNT0  = 0x00;//初始值定时时间15MS
	TIMSK=TIMSK & (~(1<<TOIE0)); //禁止产生中断
	TIFR=TIFR | (1<<TOV0); //清除中断标志
	TCCR0  = 0x05;//启动定时器1024分频
}

//端口初始化
void port_init(void)
{
	PORTD = 0;
	PORTB = 0;		/* no pullups on USB and ISP pins */
	DDRD = ~(1 << 2);	/* all outputs except PD2 = INT0 */
	DDRB = 0;             /* all USB and ISP pins inputs */
}


int main(void)
{
	uchar   i;
		
	cli(); //禁止所有中断
	port_init();
	wdt_enable(WDTO_1S);
	
	DBG1(0x00, 0, 0);       /* debug output: main starts */
	
	start=0;
	prt=0;
	last=1<<2;
	usbInit();
	usbDeviceDisconnect();  /* enforce re-enumeration, do this while interrupts are disabled! */
	i = 0;
	while(--i){             /* fake USB disconnect for > 250 ms */
		wdt_reset();
		_delay_ms(1);
	}
	usbDeviceConnect();

	ledRedOff();
	ledGreenOff();
	sei();
	for(;;)
	{	        /* main event loop */
		usbPoll();
		wdt_reset();
		if(start==1)
		{
			uchar t=Get_Bit(PINC,2);
			if(t!=last)
			{
				irbuf[prt]=TCNT0;
				timer0_init();
				last=t;
				prt++;
			}
			
			if(prt==IRBUFSIZE||(Get_Bit(TIFR,TOV0)&&prt>3))
			{
				i=0;
				start=2;
				ledRedOff();
				ledGreenOn();
				timer0_init();
				TCCR0=0;
				prt--;
			}	
		}
		
		if(start==2)
		{			
			if(usbInterruptIsReady())
			{
				if(i>=prt)
				{
					usbSetInterrupt((void *)&irbuf[i],prt+8-i);
					start=1;
					prt=0;
					last=1<<(PC2);
					ledRedOn();
					ledGreenOff();
				}
				else
				usbSetInterrupt((void *)&irbuf[i], 8);
				i+=8;
			}
			
			
		}
	}
	return 0;
}