Programming Code //####### Prototype Area ######### #include <avr/io.h> #include <avr/interrupt.h> #include <util/delay.h> #define F_CPU 1000000UL //Clock Frequency 1MHz //####### Functions############### void InitADC() // This routine initializes AVR internal ADC module to work with RC clock . Clock determines the time period necessary for performing AD conversion { ADMUX=(1<<REFS0)|(1<<REFS1); // Set (REF Voltage & Input channel) … AREF=internal 2.56v ADCSRA=(1<<ADEN)|(1<<ADPS0)|(1<<ADPS1)|(1<<ADPS2); //ADC Enabling (ADEN ..Start Conversion) & Set pre-scalar setting } uint16_t ReadADC() { //Select ADC Channel ADMUX = 0xE0; //Start Single conversion ADCSRA|=(1<<ADSC); //Wait for conversion to complete while(!(ADCSRA & (1<<ADIF))); //Clear ADIF by writing one to it ADCSRA|=(1<<ADIF); return(ADCH); //The digital value stored in the ADCH register } int main(void) { char segment [10] = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F}; //7-Segment Numbers Codes in hexadecimal DDRB=0xFF; //PORT B Output DDRD=0xFF; //PORT D Output sei(); // Enable Global Interrupts InitADC(); // Enabling the Conversion while(1) // Infinite Loop { // Temperature Calculations uint16_t adc_value=ReadADC() ; //Select .. Start .. Wait .. Clear uint8_t temp= adc_value / 4; //Getting the temp value uint8_t first = temp/10; // int (25/10) = 2 >> First uint8_t second= temp-first*10; // 25 – (2*10) = 5 >> Second PORTB=segment[first]; // send first digit to 7-segment PORTD=segment[second]; // send last digit to 7-segment _delay_ms(1000); //wait 1 sec ADCSRA |= 1<<ADSC; //Start ADC Conversion Again } }
Programming Code //####### Prototype Area ######### #include
#include #include #define F_CPU 1000000UL //Clock Frequency 1MHz
//####### Functions###############
void InitADC() // This routine initializes AVR internal ADC
module to work with RC clock. Clock determines the time period
necessary for performing AD conversion { ADMUX=(1
AVR ADC
FUNCTION CODE Start Conversion ADCSRA |= 1
Registers Description
Bit 5 ADLAR: ADC Left Adjust Result The ADLAR bit affects the
presentation of the ADC conversion result in the ADC Data Register.
Write one to ADLAR to left adjust the result. Otherwise, the result
is right adjusted. Changing the ADLAR bit will affect the ADC Data
Register immediately, regardless of any ongoing conversions.
When an ADC conversion is complete, the result is found in these
two registers. When ADCL is read, the ADC Data Register is not
updated until ADCH is read. Consequently, if the result is left
adjusted and no more than 8-bit precision is required, it is
sufficient to read ADCH. Otherwise, ADCL must be read first, then
ADCH. The ADLAR bit in ADMUX, and the MUXn bits in ADMUX affect the
way the result is read from the registers. If ADLAR is set, the
result is left adjusted. If ADLAR is cleared (default), the result
is right adjusted. Bits 3:0 MUX3:0: Analog Channel Selection Bits
The value of these bits selects which analog inputs are connected
to the ADC. If these bits are changed during a conversion, the
change will not go in effect until this conversion is complete
(ADIF in ADCSRA is set).
ADC Conversion Result After the conversion is complete (ADIF is
high), the conversion result can be found in the ADC Result
Registers (ADCL, ADCH). For single ended conversion the result is
:
1024*ref
in
VV
ADC
LM35 Calculations : We choose 2.56v as a Reference voltage ,
that mean the maximum value that can be read from the sensor is
2.56v. So: 1 C = 10 mV ( Analog ) = 4 ADC >> Linear
Relation
![28. ADC – Analog-to-Digital Converterweb.engr.Oregonstate.edu/~traylor/ece473/x_atmelpdfs/adc_system.pdfXMEGA AU [MANUAL] 339 8331F–AVR–04/2013 28. ADC – Analog-to-Digital](https://img.dokumen.tips/doc/110x75/5ea9738f6e3b2330da143e18/28-adc-a-analog-to-digital-traylorece473xatmelpdfsadcsystempdf-xmega-au.jpg)
