ATtiny10 DHT11-DHT22-Serial

ATtiny10 working with both DHT11 and DHT22 via serial. Still work in progress, but is functional. (programed in Microchip Studio)

/* * ATtiny10-DHT-11_22.c * * Created: 5/27/2022 19:03:57 * Author : Sherm * * Some of the code was ported from: * https://circuitdigest.com/microcontroller-projects/interfacing-dht11-sensor-with-pic16f877a-microcontroller * * Still work in progress.. * Now works with both DHT11 and DHT22: * DHT22 only does C and H for now. * DHT11 does C and H and F DHT11 3 4 1 2C 0022 0000 H 0083 0000C 0022 0000 H 0082 0000C 0022 0000 H 0084 0000
DHT22C 0000 0229 H 0001 0211C 0000 0230 H 0001 0200C 0000 0230 H 0001 0196 * * Original: * ATtiny10-DHT-11.c * * Created: 5/26/2022 16:26:59 * Author : Sherm

Serial Thanks to Ben Heck's Hacks youtube chanel.

* */ #define F_CPU 8000000UL#include <avr/io.h>#include <util/delay.h>#include <avr/interrupt.h>
//#define DHT11 #define DHT22
#define DHT_Pin PB2 #define TX PB0#define FIRST_LINE 0x80#define SECOND_LINE 0xC0uint8_t Check_bit, Temp_byte_1, Temp_byte_2, RH_byte_1, RH_byte_2, Sumation;//uint8_t Himudity, RH, Sumation ;
//Dht11 related definitionvoid dht_init();void find_response();uint8_t read_dht();
static volatile char Xmit;static volatile uint8_t whichBitOut = 10;
ISR(TIM0_COMPA_vect){ switch(whichBitOut){ case 1://start bit PORTB &= ~(1<<TX); //go low for start bit whichBitOut = 2; break; case 2 ... 9: if (Xmit & 0x01){ PORTB |= (1<<TX); }else{ PORTB &= ~(1<<TX); } Xmit >>= 1; whichBitOut++; break; case 10: PORTB|=(1<<TX); whichBitOut = 0; break; }}
void sendByte(uint8_t theByte){ Xmit = theByte; whichBitOut = 1; while(whichBitOut){} //wait for it to finish before another}
void print(const char *data){ while(*data != 0x00){ sendByte(*data++); }}
//leading 0void printNumLeading(uint16_t number){ uint16_t divider = 10000; for(uint8_t i=0;i<5;i++){ if(number>=divider){ sendByte((number/divider)+48); number %= divider; }else{ sendByte('0'); } divider /=10; }}
//no leading 0void printNum(uint16_t number){ uint16_t divider = 10000; uint8_t numStart = 0; for(uint8_t i=0;i<5;i++){ if(number>=divider){ sendByte((number/divider)+48); number %= divider; numStart=1; }else if(numStart){ sendByte('0'); } divider /=10; }}
void txInit(void){// CCP = 0xD8;// CLKPSR = 0b00000000; DDRB |= (1<<TX);//0b00001111; // PUEB = 0b00000100; TCCR0A = 0b00000000; TCCR0B = 0b00001001; // baud = 8000000/9600 = 833.333333 OCR0AH = 808 >> 8; //833 OCR0AL = 808 & 0xFF; TIMSK0 |= (1<<OCIE0A); sei();}
int main(void) { CCP=0xD8; CLKPSR=0x0; txInit();
while(1){ _delay_ms(2500); //must have at least 2 second interval. per datasheet dht_init(); find_response(); //may be fixed.. test// Check_bit=1; //added by sherm if(Check_bit == 1){ RH_byte_1 = read_dht(); RH_byte_2 = read_dht(); Temp_byte_1 = read_dht(); Temp_byte_2 = read_dht(); Sumation = read_dht(); if(Sumation == ((RH_byte_1+RH_byte_2+Temp_byte_1+Temp_byte_2) & 0XFF)){ sendByte('C'); //258 // sendByte(' '); //258 #ifdef DHT11 printNum(Temp_byte_1); #else // printNumLeading(Temp_byte_1); // printNumLeading(Temp_byte_2); printNum(Temp_byte_2/10); sendByte('.'); if(Temp_byte_2%10){ printNum(Temp_byte_2%10); }else{ sendByte('0'); } #endif // sendByte(' '); //printNumLeading(Temp_byte_2); // sendByte('F'); sendByte(' '); #ifdef DHT11 uint16_t f = ((Temp_byte_1*10)*18)+3200; printNum((f/100)%1000); sendByte('.'); printNum(f%1000); #else //DHT22 //uint16_t f = ((Temp_byte_2*10)*18)+3200; //printNum((f/100)%1000); //sendByte('.'); //printNum(f%1000); #endif sendByte(' '); sendByte('H'); //258 // sendByte(' '); //258 #ifdef DHT11 printNum(RH_byte_1); sendByte(' '); printNum(RH_byte_2); sendByte(' '); #else //DHT22 uint16_t H = RH_byte_1*256+RH_byte_2; // printNumLeading(RH_byte_1); // printNumLeading(RH_byte_2); printNum((H%1000)/10); sendByte('.'); if(H%10){ printNum(H%10); }else{ sendByte('0'); } #endif // printNumLeading(Sumation); sendByte(13); // printNum(Sumation); // sendByte(13); }else{ print("Check sum error\n"); } }else{ sendByte('E'); sendByte(13); /* clear_screen(); lcd_com (0x80); lcd_puts("Error!!!"); lcd_com (0xC0); lcd_puts("No Response."); */ } //print("End\n"); // _delay_ms(100); }}
//Connect to DHT:void dht_init(){// DHT_Pin_Direction= 0; //Configure RD0 as output DDRB |= (1<<DHT_Pin);// sends 0 to the sensor for 18ms PORTB &= ~(1<<DHT_Pin); _delay_ms(18);// sends 1 to the sensor for 30us PORTB |= (1<<DHT_Pin); _delay_us(30);// Configure DHT Data Pin as input DDRB &= ~(1<<DHT_Pin); }
//Check if connected: void find_response(){ Check_bit = 0; _delay_us(40); if (!(PINB & (1<<DHT_Pin))){ _delay_us(80); // }//sherm if (PINB & (1<<DHT_Pin)){ Check_bit = 1; } _delay_us(50); }
}

//read data from DHT11 or 22 uint8_t read_dht(){ uint8_t data; for(uint8_t for_count = 0; for_count < 8; for_count++){ while(!(PINB & (1<<DHT_Pin))); _delay_us(50); //was 30 if((PINB & (1<<DHT_Pin)) == 0){ data &= ~(1<<(7 - for_count)); //Clear bit (7-b) }else{ data |= (1 << (7 - for_count)); //Set bit (7-b) while((PINB & (1<< DHT_Pin))); //was waiting while high } //Wait until PORTB DHT_Pin goes LOW } return data; }

ATtiny10 actual size.

Page updated

Google Sites

Report abuse