Lux metre devresi attiny26-16 ışık ölçümü

Lux metre devresi atmel attiny26-16 mikrodenetleyici üzerine kurulu led display üzerinde lux değerini görüntülüyor ledler 2sk1061 mosfetler ile sürülmüş. İlginç bir uygulama tüm kaynak dosyalar (pcb, şema, kod) paylaşılmış ayrıca devrenin kalibrasyon bilgileride verilmiş

Lux metre devre şeması;

Dosya ve detaylar (ingilizce): Lux Meter

The Lux Meter is usually used to measure illumination. The illumination is how level of luminous flux is falling on a surface area. The luminous flux is visible component that is defined in radiant flux (light power) divided by relative sensitivity of human eyes over the visible spectrum. This means the Lux is well fit to light level from sense of human eyes.

lux.c yazılımı;

/*--------------------------------------------------*/
/* Lux meter control program (C)ChaN, 2005			*/

#include <avr/io.h>
#include <avr/signal.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <avr/eeprom.h>
#include <string.h>
#include "xitoa.h"

#define	SYSCLK		1000000

/* Bit definition for status flags */
#define	F_800	(_BV(0))		// 800 Hz timer event
#define	F_LVD	(_BV(1))		// Low battery
#define	F_POW	(_BV(2))		// Power event
#define F_PB	(_BV(3))		// Power button

/*------------------------------------------------*/
/* Global variables                               */

uint8_t Leds[5];				// LED display buffer
volatile uint8_t flags;			// Status flags
volatile uint16_t OffTimer;		// Auto power off timer

uint32_t Gain[2];
uint16_t Ofs20;

/*------------------------------------------------*/
/* Interval Timer (800Hz)                         */

SIGNAL(SIG_OVERFLOW1)
{
	static uint8_t bltimer;		// LED blink timer
	static uint8_t Col;			// Dynamic scan pointer

	if(++Col >= sizeof(Leds)) Col = 0;
	PORTA &= 0b00000100;
	PORTB = 0;

	bltimer++;
	if((bltimer & 7) == 0) {	// Check power button every 8 (100/sec)
		PORTA |= _BV(3);
		DDRA &= ~_BV(3);
		DDRA &= ~_BV(3);
		DDRA &= ~_BV(3);
		if(PINA & _BV(3)) {
			flags |= F_PB;
		} else {
			if(flags & F_PB)
				flags |= F_POW;
			flags &= ~F_PB;
		}
		PORTA &= 0b00000100;
		DDRA |= _BV(3);
	}
	if((bltimer & 0xC0) || !(flags & F_LVD))	// Blink control
		PORTB = Leds[Col];
	PORTA |= (0b00001000 << Col);

	if(--OffTimer == 0) flags |= F_POW;			// Auto power-off timer

	flags |= F_800;
}

/* Character output function for LED display (called by xitoa module) */

void putled(char c)
{
	static uint8_t wp;	// Write index
	static const prog_uint8_t seg7[]	// Segment pattern
		= {0x7E, 0x30, 0x6D, 0x79, 0x33, 0x5B, 0x5F, 0x70, 0x7F, 0x7B, 0};

	if(c == 'r') {		// Return index to left
		wp = 0;
		return;
	}
	c -= '0';			// Put a segment pattern into display buffer
	if((uint8_t)c > 9) c = 10;
	Leds[wp++] = pgm_read_byte(&seg7[(uint8_t)c]);
}

void delay (uint16_t dly)
{
	do {
		cli(); flags &= ~F_800; sei();
		while((flags & F_800) == 0);
	} while(--dly);
}

uint16_t adconv(uint8_t ch)
{
	ADMUX = ch;
	ADCSR = 0b11010011;
	while(bit_is_clear(ADCSR, ADIF));
	return ADC;
}

/*------------------------------------------------*/
/* Main Process                                   */

int main(void)
{
	uint16_t n, d;
	uint32_t v, u;

	/* Initialize ports */
	PORTA = 0b00000100;
	DDRA  = 0b11111110;

	PORTB = 0b00000101;
	DDRB  = 0b01111111;

	/* Start TC1 with 800Hz OC-A */
	OCR1C = SYSCLK/8/800-1;
	TCCR1B = _BV(CTC1) | 0b0100;
	TIMSK = _BV(TOIE1);

	eeprom_read_block(Gain, 0, sizeof(Gain));

	xfunc_out = putled;		// Join xitoa molule and my output function

	OffTimer = 48000;	// Auto power off timer (60sec)

	sei();

	/* Lamp test */
	memset(Leds, 0x7F, sizeof(Leds));
	delay(400);

	delay(10);
	Ofs20 = adconv(0x80 + 13);
	delay(10);

	cli();
	PORTA &= 0b00000100;
	PORTB = 0b00000101;
	DDRB  = 0b01111010;
	DDRB  = 0b01111010;
	DDRB  = 0b01111010;

	/* MOSI is tied to GND. Low range calibration (1250 lux at -100 mV) */
	if((PINB & _BV(0)) == 0) {
		adconv(0x80 + 11);
		Gain[0] = 1250 * 65536 / (uint32_t)(adconv(0x80 + 11) - Ofs20);
		eeprom_write_block(Gain, 0, sizeof(Gain));
		Leds[0] = 0;
	}

	/* SCK is tied to GND. High range calibration (12500 lux at -1 V) */
	if((PINB & _BV(2)) == 0) {
		adconv(0x80 + 0);
		Gain[1] = 12500 * 65536 / (uint32_t)(adconv(0x80 + 0));
		eeprom_write_block(Gain, 0, sizeof(Gain));
		Leds[1] = 0;
	}

	DDRB =  0b01111111;
	sei();

	/* Measurement loop continued until any power event occure */

	while(!(flags & F_POW)) {
		v = 0;
		for(n = 0; n < 256; n++)	// 256 times averaging to filter-out flicker
		{
			d = adconv(0x80 + 11);
			while(!(flags & F_800));
			cli(); flags &= ~F_800; sei();
			d = adconv(0x80 + 11);
			if(d < 1023) {
				d -= Ofs20;
				u = Gain[0];
			} else {
				d = adconv(0x80 + 0);
				u = Gain[1];
			}
			d = (u * (uint32_t)d) >> 16;
			v += d;
		}

		/* Refresh lux value */
		xputc('r');
		xitoa(v / 256, 10, 5);

		/* Check battrey voltage */
		DDRA &= ~_BV(1);
		d = adconv(0x80 + 1);
		cli();
		if(d >= 23)
			flags &= ~F_LVD;
		else
			flags |= F_LVD;
		sei();
		DDRA |= _BV(1);
	}

	/* Power off */
	memset(Leds, 0, sizeof(Leds));	// Clear display
	PORTA &= ~_BV(2);				// Release power hold
	for(;;);
}