scmd2.c

/*******************************************************
This program was created by the
CodeWizardAVR V3.12 Evaluation
Automatic Program Generator
© Copyright 1998-2014 Pavel Haiduc, HP InfoTech s.r.l.
http://www.hpinfotech.com

Project : 
Version : 
Date    : 19.01.2015
Author  : 
Company : 
Comments: 

Chip type               : ATmega328P
Program type            : Application
AVR Core Clock frequency: 16,000000 MHz
Memory model            : Small
External RAM size       : 0
Data Stack size         : 512
*******************************************************/

#include <mega328p.h>

// Voltage Reference: AREF pin
#define ADC_VREF_TYPE ((0<<REFS1) | (0<<REFS0) | (0<<ADLAR))

// Global variables here
bit sample=0, firstrun=1;
char channel[]="ABCD";

// Standard Input/Output functions
#include <stdio.h>
#include <delay.h>

int is_button_pressed(void) {
    unsigned int state = 0;

    if (!PINB.1) {
        delay_ms(25);
        if (!PINB.1) state = 1;
        while (!PINB.1);
    }
    return state;
}

// Read the AD conversion result
unsigned int read_adc(void) {
    unsigned int counter0 = 5, counter1 = 16;
    unsigned long int result0 = 0, result1 = 0;

    // Delay needed for the stabilization of the ADC input voltage
    delay_us(10);
    // Start the AD conversion
    ADCSRA|=(1<<ADSC);
    // Discard the first conversion
    while ((ADCSRA & (1<<ADIF))==0);
    ADCSRA|=(1<<ADIF); 
    
    while (counter0){
        // Increase resolution by oversampling
        while (counter1){
            // Wait for the AD conversion to complete
            while ((ADCSRA & (1<<ADIF))==0);
            ADCSRA|=(1<<ADIF);
            result1 += ADCW;
            counter1--;
        }
        result1 >>= 2;

        result0 += result1;
        result1 = 0;
        counter1 = 16;
        counter0--;
    }
    result0 /= 5;
    return result0;
}

void init(void) {
    // Crystal Oscillator division factor: 1
    #pragma optsize-
    CLKPR=(1<<CLKPCE);
    CLKPR=(0<<CLKPCE) | (0<<CLKPS3) | (0<<CLKPS2) | (0<<CLKPS1) | (0<<CLKPS0);
    #ifdef _OPTIMIZE_SIZE_
    #pragma optsize+
    #endif

    // Input/Output Ports initialization
    // All unused ports - pull-up inputs

    PORTB=0b11111110; //pb0 - LED (output, low), pb1 - Switch (input, pull-up)
    DDRB=0b00000001;  

    PORTC=0b11110000;
    DDRC=0b00000000;

    PORTD=0b01111011; //pd7 - LED (output, low), pd3 - input (input, pull-up), pd2 - DSR (output, low).
    DDRD=0b10000100;

    // Timer/Counter 0 initialization
    // Clock source: System Clock
    // Clock value: Timer 0 Stopped
    // Mode: Normal top=0xFF
    // OC0A output: Disconnected
    // OC0B output: Disconnected
    TCCR0A=(0<<COM0A1) | (0<<COM0A0) | (0<<COM0B1) | (0<<COM0B0) | (0<<WGM01) | (0<<WGM00);
    TCCR0B=(0<<WGM02) | (0<<CS02) | (0<<CS01) | (0<<CS00);
    TCNT0=0x00;
    OCR0A=0x00;
    OCR0B=0x00;

    // Timer/Counter 1 initialization
    // Clock source: System Clock
    // Clock value: Timer1 Stopped
    // Mode: Normal top=0xFFFF
    // OC1A output: Disconnected
    // OC1B output: Disconnected
    // 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=(0<<COM1A1) | (0<<COM1A0) | (0<<COM1B1) | (0<<COM1B0) | (0<<WGM11) | (0<<WGM10);
    TCCR1B=(0<<ICNC1) | (0<<ICES1) | (0<<WGM13) | (0<<WGM12) | (0<<CS12) | (0<<CS11) | (0<<CS10);
    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
    // OC2A output: Disconnected
    // OC2B output: Disconnected
    ASSR=(0<<EXCLK) | (0<<AS2);
    TCCR2A=(0<<COM2A1) | (0<<COM2A0) | (0<<COM2B1) | (0<<COM2B0) | (0<<WGM21) | (0<<WGM20);
    TCCR2B=(0<<WGM22) | (0<<CS22) | (0<<CS21) | (0<<CS20);
    TCNT2=0x00;
    OCR2A=0x00;
    OCR2B=0x00;

    // Timer/Counter 0 Interrupt(s) initialization
    TIMSK0=(0<<OCIE0B) | (0<<OCIE0A) | (0<<TOIE0);

    // Timer/Counter 1 Interrupt(s) initialization
    TIMSK1=(0<<ICIE1) | (0<<OCIE1B) | (0<<OCIE1A) | (0<<TOIE1);

    // Timer/Counter 2 Interrupt(s) initialization
    TIMSK2=(0<<OCIE2B) | (0<<OCIE2A) | (0<<TOIE2);

    // External Interrupt(s) initialization
    // INT0: Off
    // INT1: Off
    // Interrupt on any change on pins PCINT0-7: Off
    // Interrupt on any change on pins PCINT8-14: Off
    // Interrupt on any change on pins PCINT16-23: Off
    EICRA=(0<<ISC11) | (0<<ISC10) | (0<<ISC01) | (0<<ISC00);
    EIMSK=(0<<INT1) | (0<<INT0);
    PCICR=(0<<PCIE2) | (0<<PCIE1) | (0<<PCIE0);

    // USART initialization
    // Communication Parameters: 8 Data, 1 Stop, No Parity
    // USART Receiver: Off
    // USART Transmitter: On
    // USART0 Mode: Asynchronous
    // USART Baud Rate: 38400
    UCSR0A=(0<<RXC0) | (0<<TXC0) | (0<<UDRE0) | (0<<FE0) | (0<<DOR0) | (0<<UPE0) | (0<<U2X0) | (0<<MPCM0);
    UCSR0B=(0<<RXCIE0) | (0<<TXCIE0) | (0<<UDRIE0) | (0<<RXEN0) | (1<<TXEN0) | (0<<UCSZ02) | (0<<RXB80) | (0<<TXB80);
    UCSR0C=(0<<UMSEL01) | (0<<UMSEL00) | (0<<UPM01) | (0<<UPM00) | (0<<USBS0) | (1<<UCSZ01) | (1<<UCSZ00) | (0<<UCPOL0);
    UBRR0H=0x00;
    UBRR0L=0x19;

    // Analog Comparator initialization
    // Analog Comparator: Off
    // The Analog Comparator's positive input is
    // connected to the AIN0 pin
    // The Analog Comparator's negative input is
    // connected to the AIN1 pin
    ACSR=(1<<ACD) | (0<<ACBG) | (0<<ACO) | (0<<ACI) | (0<<ACIE) | (0<<ACIC) | (0<<ACIS1) | (0<<ACIS0);
    ADCSRB=(0<<ACME);
    // Digital input buffer on AIN0: On
    // Digital input buffer on AIN1: On
    DIDR1=(0<<AIN0D) | (0<<AIN1D);

    // ADC initialization
    // ADC Clock frequency: 125,000 kHz
    // ADC Voltage Reference: AREF pin
    // ADC Auto Trigger Source: Free Running
    // Digital input buffers on ADC0: Off, ADC1: Off, ADC2: Off, ADC3: Off
    // ADC4: On, ADC5: On
    DIDR0=(0<<ADC5D) | (0<<ADC4D) | (1<<ADC3D) | (1<<ADC2D) | (1<<ADC1D) | (1<<ADC0D);
    ADMUX=ADC_VREF_TYPE;
    ADCSRA=(1<<ADEN) | (0<<ADSC) | (1<<ADATE) | (0<<ADIF) | (0<<ADIE) | (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);
    ADCSRB=(0<<ADTS2) | (0<<ADTS1) | (0<<ADTS0);

    // SPI initialization
    // SPI disabled
    SPCR=(0<<SPIE) | (0<<SPE) | (0<<DORD) | (0<<MSTR) | (0<<CPOL) | (0<<CPHA) | (0<<SPR1) | (0<<SPR0);

    // TWI initialization
    // TWI disabled
    TWCR=(0<<TWEA) | (0<<TWSTA) | (0<<TWSTO) | (0<<TWEN) | (0<<TWIE);
}

void main(void) {
    init();

    while (1) {
        if (!PIND.3) { // Analogue circuit is powered up
            if (firstrun) {
                PORTB.0 = 1; // LED-G
                PORTD.7 = 0; // LED-R
                PORTD.2 = 0; // DSR
                firstrun = 0;
            }

            if (sample) {
                printf("%c%i\r\n",channel[ADMUX&7],read_adc());
                ADMUX++;
                if (ADMUX == (0x04 | ADC_VREF_TYPE)) ADMUX = 0x00 | ADC_VREF_TYPE;
            }

            if (is_button_pressed()) {
                sample ^= 1;
                PORTB.0 ^= 1; // LED-G
                PORTD.7 ^= 1; // LED-R
            }
        } else {
            sample = 0;
            PORTB.0 = 0; // LED-G 
            PORTD.7 = 0; // LED-R
            PORTD.2 = 1; // DSR
            firstrun = 1;
        }
    }
}