ADC Driver

Analog-to-Digital Converter Library. More...

Files
file	adc.h
	Analog-to-Digital Converter API Header.
file	adc.c
	Analog-to-Digital Converter API Implementation.

Enumerations
enum	ADCRef { AREF, AVCC, AINT1, AINT2 }
	ADC Reference Voltage options. More...

Functions
void	adcInit (ADCRef ref)
	Initialize the ADC Hardware. More...
void	adcStart (uint8_t channel)
	Start a conversion on a given channel. More...
uint8_t	adcReady (void)
	Check if a result is ready. More...
uint16_t	adcGet (uint8_t next)
	Get the conversion results. More...
void	adcClose (void)
	Disable the ADC to save energy. More...

Detailed Description

Analog-to-Digital Converter Library.

With 10bit Output and selectable Reference Voltage.

Enumeration Type Documentation

enum ADCRef

ADC Reference Voltage options.

Enumerator
AREF	External Reference Voltage.
AVCC	Supply Voltage.
AINT1	Internal Reference 1 (1.1V)
AINT2	Internal Reference 2 (2.56V)

Definition at line 45 of file adc.h.

             {
    AREF, 
    AVCC, 
    AINT1, 
    AINT2 
} ADCRef;

Function Documentation

void adcClose

(

void

)

Disable the ADC to save energy.

Definition at line 107 of file adc.c.

                {
    // deactivate adc
    ADCSRA &= ~(1 << ADSC);
    PRR0 |= (1 << PRADC);
    ADCSRA &= ~(1 << ADEN);
}

uint16_t adcGet

(

uint8_t

next

)

Get the conversion results.

Parameters

next	Start next conversion if != 0

Returns

10bit ADC value

Definition at line 96 of file adc.c.

References adcReady().

Referenced by getVoltage().

                              {
    // Return measurements result
    // Start next conversion
    uint16_t temp = 0;
    while (!adcReady());
    temp = ADC;
    if (next)
        ADCSRA |= (1 << ADSC); // Start next conversion
    return temp;
}

void adcInit

(

ADCRef

ref

)

Initialize the ADC Hardware.

Parameters

ref	Reference Voltage.

Definition at line 44 of file adc.c.

References AINT1, AINT2, AREF, and AVCC.

Referenced by xyInit().

                         {
    // Enable ADC Module, start one conversion, wait for finish
    PRR0 &= ~(1 << PRADC); // Disable ADC Power Reduction (Enable it...)
    switch(ref) {
        case AVCC:
            ADMUX = (1 << REFS0);
            break;

        case AINT1:
            ADMUX = (1 << REFS1);
            break;

        case AINT2:
            ADMUX = (1 << REFS1) | (1 << REFS0);
            break;

        case AREF:
            ADMUX &= ~((1 << REFS0) | (1 << REFS1));
            break;
    }

    ADCSRA = (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0); // Prescaler 128
    ADCSRB = 0;
    ADCSRA |= (1 << ADEN) | (1 << ADSC); // Start ADC, single conversion
}

uint8_t adcReady

(

void

)

Check if a result is ready.

Returns

1 if conversion is done.

Definition at line 86 of file adc.c.

Referenced by adcGet(), and getVoltage().

                   {
    // Is the measurement finished
    if (ADCSRA & (1 << ADSC)) {
        // ADSC bit is set
        return 0;
    } else {
        return 1;
    }
}

void adcStart

(

uint8_t

channel

)

Start a conversion on a given channel.

Parameters

channel

Channel (0 - 15)

Definition at line 70 of file adc.c.

Referenced by getVoltage().

                               {
    // Start a measurement on channel
    if (channel > 15) {
        channel = 0;
    }
    if (channel > 7) {
        channel -= 8;
        ADCSRB |= (1 << MUX5);
    } else {
        ADCSRB &= ~(1 << MUX5);
    }
    ADMUX &= ~0x1F; // Delete MUX0:4
    ADMUX |= channel;
    ADCSRA |= (1 << ADSC);
}