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#define F_CPU 1000000UL
#include
#include
#include
#define LCD_RS PD2
#define LCD_RW PD5
#define LCD_E PD6
#define LCD_DB0 PB0
#define LCD_DB1 PB1
#define LCD_DB2 PB2
#define LCD_DB3 PB3
#define LCD_DB4 PB4
#define LCD_DB5 PB5
#define LCD_DB6 PB6
#define LCD_DB7 PB7
#define DHT22_DDR DDRD
#define DHT22_PORT PORTD
#define DHT22_PIN PIND
#define DHT22_DATA_PIN PD4
#define BUTTON1_PIN PA2
#define BUTTON2_PIN PA3
enum DisplayMode {
LM35,
DHT22
};
void lcd_command(unsigned char cmd) {
_delay_ms(100);
PORTD &= ~(1 << LCD_RS);
PORTD &= ~(1 << LCD_RW);
PORTD |= (1 << LCD_E);
PORTB = cmd;
PORTD &= ~(1 << LCD_E);
PORTD |= (1 << LCD_E);
}
void lcd_data(unsigned char data) {
_delay_ms(100);
PORTD |= (1 << LCD_RS);
PORTD &= ~(1 << LCD_RW);
PORTD |= (1 << LCD_E);
PORTB = data;
PORTD &= ~(1 << LCD_E);
PORTD |= (1 << LCD_E);
}
void lcd_init() {
DDRB = 0xFF;
DDRD |= (1 << LCD_RS) | (1 << LCD_RW) | (1 << LCD_E);
lcd_command(0x30);
_delay_ms(5);
lcd_command(0x30);
_delay_us(100);
lcd_command(0x30);
_delay_us(100);
lcd_command(0x38);
lcd_command(0x06);
lcd_command(0x01);
lcd_command(0x0F);
}
void lcd_clear() {
lcd_command(0x01);
}
void lcd_goto_row2() {
lcd_command(0xC0);
}
void lcd_print(char *str) {
unsigned char i = 0;
while (str[i] != 0) {
lcd_data(str[i]);
i++;
}
}
void lm335_setup() {
ADMUX = (1 << REFS0);
ADCSRA = (1 << ADEN) | (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);
}
float lm335_read() {
uint16_t adc_value;
float temperature;
ADCSRA |= (1 << ADSC);
while (ADCSRA & (1 << ADSC));
while (ADCSRA & (1 << ADSC));
adc_value = ADC;
temperature = adc_value * 5.0 / 1024.0;
temperature = (temperature - 0.5) * 100.0;
return temperature;
}
void temp_indoor() {
float temp = lm335_read();
char temp_str[10];
int celsius_temp = (273.15 - temp) / 10;
sprintf(temp_str, "%d.%d C", celsius_temp, abs((int)temp % 10));
lcd_clear();
lcd_print("Temp: ");
lcd_print(temp_str);
_delay_ms(1000);
}
void start_signal(){
DHT22_DDR |= (1 << DHT22_DATA_PIN);
DHT22_PORT &= ~(1 << DHT22_DATA_PIN);
_delay_ms(18);
DHT22_PORT |= (1 << DHT22_DATA_PIN);
_delay_us(40);
DHT22_DDR &= ~(1 << DHT22_DATA_PIN);
}
void check_response() {
while (DHT22_PIN & (1 << DHT22_DATA_PIN));
while ((DHT22_PIN & (1 << DHT22_DATA_PIN)) == 0);
while (DHT22_PIN & (1 << DHT22_DATA_PIN));
}
uint8_t read_data() {
uint8_t i, j;
uint8_t data = 0;
for (j = 0; j < 8; j++) {
while ((DHT22_PIN & (1 << DHT22_DATA_PIN)) == 0);
_delay_us(30);
if (DHT22_PIN & (1 << DHT22_DATA_PIN)) {
data |= (1 << (7 - j));
}
while (DHT22_PIN & (1 << DHT22_DATA_PIN));}
return data;
}
void temp_outdoor() {
char temp_str[10];
char humidity_str[10];
uint8_t dht_data[5];
lcd_clear();
start_signal();
check_response();
for (int i = 0; i < 5; i++) {
dht_data[i] = read_data();
}
uint16_t humidity = (dht_data[0] << 8) | dht_data[1];
int16_t temp = (dht_data[2] << 8) | dht_data[3];
if (temp & 0x8000) {
temp = -(temp & 0x7FFF);
}
int celsius_temp = temp / 10;
sprintf(temp_str, "%d.%d C", celsius_temp, abs(temp % 10));
int humidity_int = humidity / 10;
sprintf(humidity_str, "%d.%d %%", humidity_int, abs(humidity % 10));
lcd_clear();
lcd_print("Temp: ");
lcd_print(temp_str);
lcd_goto_row2();
lcd_print("Humid: ");
lcd_print(humidity_str);
_delay_ms(1000);
}
int main() {
lcd_init();
lm335_setup();
dht22_init();
enum DisplayMode displayMode = LM35;
while (1) {
display_time();
if (PINA & (1 << BUTTON1_PIN)) {
displayMode = LM35;
} else if (PINA & (1 << BUTTON2_PIN)) {
displayMode = DHT22;
}
switch (displayMode) {
case LM35:
temp_indoor();
break;
case DHT22:
temp_outdoor();
break;
}
}
return 0;
}

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