Mikroelektronika MIKROE-350 Datenbogen

ADC (Analog to Digital Converter) module is available with a number of AVR micros. Library func-
tion 

ADC_Read

is included to provide you comfortable work with the module in single-ended mode.

This example code reads analog value from channel 2 and displays it on PORTB and PORTC.

program ADC_on_LEDs

dim adc_rd as word

main:

DDRB = 0xFF               ' Set PORTB as output 

DDRC = 0xFF               ' Set PORTC as output 

while TRUE

temp_res = ADC_Read(2)  ' get ADC value from 2nd channel

PORTB = adc_rd          ' display adc_rd[7..0]
PORTC = Hi(adc_rd)      ' display adc_rd[9..8]

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- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

sub function ADC_Read(dim channel as byte) as word

10-bit or 12-bit (MCU dependent) unsigned value from the specified 

channel

.

Initializes AVR ’s internal ADC module to work with XTAL frequency prescaled
by 128. Clock determines the time period necessary for performing A/D conver-
sion.

Parameter 

channel

represents the channel from which the analog value is to be

acquired. Refer to the appropriate datasheet for channel-to-pin mapping.

Nothing.

dim tmp as word
...

tmp = ADC_Read(2)  ' Read analog value from channel 2