#include "LCD.h"
#include <avr/io.h>
#include <util/delay.h>
#include <stdlib.h>
#include <math.h>
#include "smart.h"
#define BCOEFFICIENT 3950 // The beta coefficient of the thermistor (usually 3000-4000)
#define THERMISTORNOMINAL 10000 // resistance at 25 degrees C
#define TEMPERATURENOMINAL 25 // temp. for nominal resistance (almost always 25 C)
#define SERIESRESISTOR 10000 // the value of the 'other' resistor
float fCalcNtc(int wADCVal) // from ADC
{
double fRntc;
fRntc = ((SERIESRESISTOR * ( 1023.0 - (float) wADCVal) /(float) wADCVal)); // SERIESRESISTOR = pullup resistor
return(fRntc);
}
// calculate temperature from resistorvalue
float fCalcTemp( float fRntc)
{
float fTemp;
fTemp = (1.0 / ( (log(fRntc/THERMISTORNOMINAL))/BCOEFFICIENT + 1.0/298.0)) - 273.0; //log = ln
return( fTemp);
}
/*const unsigned int ad_table[] = {
991,989,987,985,983,980,978,975,973,970, //-40'C ~-31'C
966,963,960,957,953,949,945,941,937,932, //-30'C ~-21'C
927,922,918,912,907,900,895,889,882,875, //-20'C ~-11'C
868,861,854,847,839,830,822,814,806,796, //-10'C ~ -1'C
786,778,769,759,749,737,728,718,707,696, // 0'C ~ 9'C
684,674,663,652,640,627,617,606,595,582, // 10'C ~ 19'C
569,559,548,536,524,511,501,490,478,466, // 20'C ~ 29'C
454,444,434,423,411,400,390,381,370,360, // 30'C ~ 39'C
349,341,332,322,313,303,295,287,279,270, // 40'C ~ 49'C
262,254,247,240,232,225,219,212,206,199, // 50'C ~ 59'C
193,187,182,176,170,165,160,155,151,146, // 60'C ~ 69'C
141,137,133,129,124,120,117,113,110,106, // 70'C ~ 79'C
103,100, 97, 94, 91, 88, 85, 83, 80, 78, // 80'C ~ 89'C
75, 73, 71, 69, 66, 64, 62, 61, 59, 57, // 90'C ~ 99'C
55, 53, 50, 47, 44, 42, 41, 41, 41, 41, //100'C ~109'C
41, 40, 39, 38, 36, 35, 34, 33, 32, 32, //110'C ~119'C
31 };
*/
volatile unsigned int uiCnt;
char cBuf[5] = {0, };
char cFlag = 0;
void TC1_Init()
{
/* 레지스터 설정 */
// 16 BIT Timer/Counter //
TCCR1A = 0X00;//0B 0000 0000 -> NORMAL MODE, NO PWM MODE
TCCR1B = 0X83;//0B 1000 0011 -> FALLING EDGE, NORMAL MODE, 64 분주
TCCR1C = 0X00;//0B 0000 0000 -> BLOCK COMPARE MODE
TCNT1H = 0X00;//0B 0000 0000 -> START FROM 0
TCNT1L = 0X00;//0B 0000 0000 -> START FROM 0
TIMSK1 = 0X01;//0B 0000 0001 -> OVERFLOW REGISTER ENABLE
TIFR1 = 0X00;//0B 0000 0000 ->BIT CLEAR, FLACK BIT CLEAR
SREG |=0X80;//0B 1000 0000 -> GLOBAL INTERRUPT ENABLE
TCNT1H = TCNT1L >> 8;
SREG |=0X80;// 0B 1000 0000 -> GLOBAL INTERRUPT ENABLE
}
void ADC_Init()
{
ADCSRA = 0x00; // init
ADCSRA = 0x85; // Enable adc, 분주비 32
ADCSRB = 0x00; // free running mode
ADMUX = 0x40; // select adc input 0
}
void MTW()
{
char cBuffer[20]={0, };
char cCS[3] = {0, };
int iCnt;
char ucCS;
cBuffer[0] = '$';
cBuffer[1] = 'J';
cBuffer[2] = 'H';
cBuffer[3] = 'M';
cBuffer[4] = 'T';
cBuffer[5] = 'W';
cBuffer[6] = ',';
cBuffer[7] = '0';
cBuffer[8] = cBuf[0];
cBuffer[9] = cBuf[1];
cBuffer[10] = cBuf[2];
cBuffer[11] = cBuf[3];
cBuffer[12] = ',';
cBuffer[13] = 'C';
cBuffer[14] = '*';
//checksum - from $ to * XOR
for(iCnt = 1; iCnt < 14; ++iCnt)
{
ucCS ^= cBuffer[iCnt];
}
itoa(ucCS, cCS, 16);
cBuffer[15] = cCS[0];
cBuffer[16] = cCS[1];
/*itoa( (ucCS & 0xF0), cBuffer[15], 16);
itoa( (ucCS & 0x0F), cBuffer[16], 16);*/
cBuffer[17] = 10;
cBuffer[18] = 13;
ucCS = 0;
USART_PRINT(cBuffer);
}
int main(void)
{
unsigned int uiSum=0;
int iCnt;
int uiTemp=0;
unsigned char i;
double steinhart, Res, Temp;
LCD_Init();
ADC_Init();
TC1_Init();
USART0_INIT();
LCD_Print(" Current Temp.");
LCD_INST(0x0C);
LCD_INST(0x40);
LCD_Symbol();
while(1)
{
uiSum = 0;
ADCSRA = 0xD5;
while((ADCSRA & 0x10) != 0x10);
for(i=0; i<100; ++i)
{
ADCSRA = 0xD5;
while((ADCSRA & 0x10) != 0x10);
uiSum += ( (int)ADCL + ((int)ADCH<<8) ) ;
}
uiSum /= 100; // uiSum = uiSum / 100, 아날로그 신호의 평균값을 내준다.
Res = fCalcNtc(uiSum); // calculate temperature from resistorvalue
Temp = fCalcTemp(Res); // calculate temperature from resistorvalue
Temp = Temp * 10;
itoa(Temp, cBuf, 10);
cBuf[3] = cBuf[2];
cBuf[2] = '.';
LCD_INST(0xC5);
LCD_Print(cBuf);
LCD_Data(0x00);
LCD_Data('C');
_delay_ms(1000);
}
return 0;
}
void __vector_20(void)
{
cFlag ^= 0x01;
if(cFlag == 0)
MTW();
}
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