, kali ini saya akan membahas penerapannya yaitu membaca nilai sensor garis/ proximity via ADC. Untuk compilernya saya menggunakan codevision AVR, karena lebih simpel dan kita tidak perlu menghafal register-register AVR.
Langsung saja, buka codevision klik File- New - Project.Jangan lupa setting chip dan clock. Setelah itu klik tab ADC
Sekarang klik File - Generate, Save and Exit.. Simpan Filenya.
/****************************************************
Project : Pembacaan Nilai ADC pada sensor garis
Author : Rifqi Arridho Abid
Company : EIRRG
Chip type : ATmega8535
Program type : Application
AVR Core Clock frequency : 16,000000 MHz
Memory model : Small
External RAM size : 0
Data Stack size : 128
*****************************************************/
#include <mega8535.h>
#include <delay.h>
#include <stdio.h>
#include <delay.h>
// Alphanumeric LCD Module functions
#include <alcd.h>
#define ADC_VREF_TYPE 0x40
// Membaca hasil ADC
unsigned int read_adc(unsigned char adc_input)
{
ADMUX=adc_input | (ADC_VREF_TYPE & 0xff);
delay_us(10); // Delay dibutuhkan untuk penyetabil tegangan input ADC
ADCSRA|=0x40; // Memulai konversi analog - digital
// Menunggu konversi analog-digital selesai
while ((ADCSRA & 0x10)==0);
ADCSRA|=0x10;
return ADCW;
}
// Declare your global variables here
unsigned int s1,s2,s3,s4,s5,s6,s7,s8;
unsigned char kata[16],kata1[16];
void data_sensor()
{
s1=read_adc(0);
delay_us(10);
s2=read_adc(1);
delay_us(10);
s3=read_adc(2);
delay_us(10);
s4=read_adc(3);
delay_us(10);
s5=read_adc(4);
delay_us(10);
s6=read_adc(5);
delay_us(10);
s7=read_adc(6);
delay_us(10);
s8=read_adc(7);
delay_us(10);
//Menampilkan nilai ADC ke lcd
sprintf(kata,"%d %d %d %d",s1,s2,s3,s4);
sprintf(kata1,"%d %d %d %d",s5,s6,s7,s8);
lcd_clear();
lcd_gotoxy(0,0);
lcd_puts(kata);
lcd_gotoxy(0,1);
lcd_puts(kata1);
delay_ms (100);
}
void main(void)
{
// Declare your local variables here
// Input/Output Ports initialization
// Port A initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=T
PORTA=0x00;
DDRA=0x00;
// Port B initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=T
PORTB=0x00;
DDRB=0x00;
// Port C initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=T
PORTC=0x00;
DDRC=0x00;
// Port D initialization
// Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=In
// State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=T
PORTD=0x00;
DDRD=0x00;
// Timer/Counter 0 initialization
// Clock source: System Clock
// Clock value: Timer 0 Stopped
// Mode: Normal top=0xFF
// OC0 output: Disconnected
TCCR0=0x00;
TCNT0=0x00;
OCR0=0x00;
// Timer/Counter 1 initialization
// Clock source: System Clock
// Clock value: Timer1 Stopped
// Mode: Normal top=0xFFFF
// OC1A output: Discon.
// OC1B output: Discon.
// Noise Canceler: Off
// Input Capture on Falling Edge
// Timer1 Overflow Interrupt: Off
// Input Capture Interrupt: Off
// Compare A Match Interrupt: Off
// Compare B Match Interrupt: Off
TCCR1A=0x00;
TCCR1B=0x00;
TCNT1H=0x00;
TCNT1L=0x00;
ICR1H=0x00;
ICR1L=0x00;
OCR1AH=0x00;
OCR1AL=0x00;
OCR1BH=0x00;
OCR1BL=0x00;
// Timer/Counter 2 initialization
// Clock source: System Clock
// Clock value: Timer2 Stopped
// Mode: Normal top=0xFF
// OC2 output: Disconnected
ASSR=0x00;
TCCR2=0x00;
TCNT2=0x00;
OCR2=0x00;
// External Interrupt(s) initialization
// INT0: Off
// INT1: Off
// INT2: Off
MCUCR=0x00;
MCUCSR=0x00;
// Timer(s)/Counter(s) Interrupt(s) initialization
TIMSK=0x00;
// USART initialization
// USART disabled
UCSRB=0x00;
// Analog Comparator initialization
// Analog Comparator: Off
// Analog Comparator Input Capture by Timer/Counter 1: Off
ACSR=0x80;
SFIOR=0x00;
// ADC initialization
// ADC Clock frequency: 125,000 kHz
// ADC Voltage Reference: AVCC pin
// ADC High Speed Mode: Off
// ADC Auto Trigger Source: ADC Stopped
ADMUX=ADC_VREF_TYPE & 0xff;
ADCSRA=0x87;
SFIOR&=0xEF;
// SPI initialization
// SPI disabled
SPCR=0x00;
// TWI initialization
// TWI disabled
TWCR=0x00;
// Alphanumeric LCD initialization
// Connections specified in the
// Project|Configure|C Compiler|Libraries|Alphanumeric LCD menu:
// RS - PORTC Bit 0
// RD - PORTC Bit 1
// EN - PORTC Bit 2
// D4 - PORTC Bit 4
// D5 - PORTC Bit 5
// D6 - PORTC Bit 6
// D7 - PORTC Bit 7
// Characters/line: 16
lcd_init(16);
while (1)
{
// Place your code here
data_sensor (); //memanggil void data_sensor
}
}
#define ADC_VREF_TYPE 0x40
// Membaca hasil ADC
unsigned int read_adc(unsigned char adc_input)
{
ADMUX=adc_input | (ADC_VREF_TYPE & 0xff);
delay_us(10); // Delay dibutuhkan untuk penyetabil tegangan input ADC
ADCSRA|=0x40; // Memulai konversi analog - digital
// Menunggu konversi analog-digital selesai
while ((ADCSRA & 0x10)==0);
ADCSRA|=0x10;
return ADCW;
}
// ADC initialization
// ADC Clock frequency: 125,000 kHz
// ADC Voltage Reference: AVCC pin
// ADC High Speed Mode: Off
// ADC Auto Trigger Source: ADC Stopped
ADMUX=ADC_VREF_TYPE & 0xff;
ADCSRA=0x87;
SFIOR&=0xEF;
Blok program diatas adalah inisialisasi dan prosedur baca ADC yang dibentuk oleh codevision. Coba kita bandingkan dengan setting registernya.Misalkan register ADMUX=0x60 maka bit REFS1 = 0 dan bit REFS0=1. Jadi ADC menggunakan tegangan referensi (Vref) = Vcc.
Dibawah ini hasil pembacaan sensor garis yang saya buat, pada saat di warna putih bernilai < 50 dan pada saat di warna hitam >700 (menggunakan mode 10 bit).
15.18
Rifqi Arridho Abid
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