arduino——ATtiny85 SSD1306 + DHT

ATtiny85 SSD1306 + DHT

What to learn

1.ATtiny85 SSD1306 + DHT Display function and temperature
2. understand arduino Medium millis() function
Click on ATtiny85 SSD1306 + DHT Start online simulation

Source code

/* Why the heart icon? Because I thought it was cool and I want to use it in the future with some heartbeat sensor. I needed to keep it somewhere and it was here. ;) */

#include <dht.h>
#include <TinyWireM.h>
#include <Tiny4kOLED.h>

#define DHT22_PIN PB1

const unsigned char  img_heart_small[] PROGMEM = {
    
  0x00, 0x00, 0xc0, 0xe0, 0xe0, 0xe0, 0xc0, 0x80, 0x80, 0x80, 0xc0, 0xe0, 0xe0, 0xe0, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x1f, 0x0f, 0x07, 0x03, 0x01, 0x00, 0x00, 0x00
};// Big heart icon 

const unsigned char  img_heart_big[] PROGMEM = {
    
  0xe0, 0xf0, 0xf8, 0xf8, 0xf8, 0xf8, 0xf0, 0xe0, 0xe0, 0xe0, 0xf0, 0xf8, 0xf8, 0xf8, 0xf8, 0xf0, 0xe0, 0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff, 0x7f, 0x3f, 0x1f, 0x0f, 0x07, 0x03, 0x01, 0x00
};// Be careful with the icon 

const unsigned char  img_thermometer[] PROGMEM = {
    
  0x00, 0xfe, 0x03, 0xfe, 0x50,
  0x00, 0xff, 0x00, 0xff, 0x55,
  0x60, 0x9f, 0x80, 0x9f, 0x65,
};// Thermometer icon 

dht DHT;

void splash() {
    
  oled.clear();
  oled.setCursor(15, 1);
  oled.print(F("ATtiny85+SSD1306"));

  oled.setCursor(42, 3);
  oled.print(F("Example"));

  oled.setCursor(35, 7);
  oled.print(F("wokwi.com"));
}// Fixed display 

void heartBeat() {
    
  static char big = 1;
  static long startTime = 0;
  long currentTime;

  // Get current time
  currentTime = millis();

  // Update if 200ms passed
  if ((currentTime - startTime) > 200) {
    
    startTime = currentTime;
    big = 1 - big;// Flip BIG The state of 

    if (big) {
    
      oled.bitmap(20, 4, 37, 6, img_heart_big);// Specific position display 
    } else {
    
      oled.bitmap(20, 4, 37, 6, img_heart_small);
    }
  }
}

void prepareDisplay() {
    
  unsigned int i, k;
  unsigned char ch[5];

  oled.clear();
  oled.begin();

  oled.setCursor(20, 1);
  oled.print(F("ATtiny85+SSD1306"));
  oled.setCursor(3, 2);
  oled.print(F("temperature|humidity"));

  oled.bitmap(105, 4, 110, 7, img_thermometer);
  oled.setCursor(57, 4);
  oled.print(F("24.0C"));
  oled.setCursor(57, 5);
  oled.print(F("40.0%"));

  oled.bitmap(10, 5, 17, 2, img_heart_small);
}// Pre display 

float getTemperature() {
    
  return DHT.temperature;
}// obtain DHT temperature 

float getHumidity() {
    
  return DHT.humidity;
}// obtain DHT humidity 

void setup() {
    
  pinMode(DHT22_PIN, INPUT);

  oled.begin(128, 64, sizeof(tiny4koled_init_128x64br), tiny4koled_init_128x64br);

  //  This library provides two Fonts ,FONT8X16 and FONT6X8
  oled.setFont(FONT6X8);

  //  Clear all memory 
  oled.clear();
  oled.on();

  splash();

  delay(3000);
  prepareDisplay();
}

void loop() {
    
  static long startTime = 0;
  long currentTime;

  DHT.read22(DHT22_PIN);

  // Get current time
  currentTime = millis();

  //  Check 1 Seconds later 
  if ((currentTime - startTime) > 1000) {
    
    startTime = currentTime;

    //  to update  temperature
    float temperature = getTemperature();

    // Set  cursor 
    oled.setCursor(57, 4);

    // Fix negative temperature 
    if (temperature < 0) {
    
      oled.print("-");
      temperature = (uint8_t)temperature - 52;
    }// Negative temperature conversion 

    // Print to display
    oled.print(temperature, 1);
    oled.print("C ");

    // Update humidity
    float humidity = getHumidity();

    // Set cursor
    oled.setCursor(57, 5);

    // Print to display
    oled.print(humidity, 1);
    oled.print("% ");

    oled.bitmap(105, 4, 110, 7, img_thermometer);
  }

  heartBeat();
}

3.1millis() Introduce

This function is used to return Arduino The number of milliseconds when the board starts running the current program . This figure is around 50 Overflow in days , That is, back to zero .

unsigned long time; void setup() { 
   Serial.begin(9600); 
} 
 
void loop() { 
   Serial.print("Time:"); time = millis();
   //prints time since program started
   Serial.println(time); 
   // wait a second so as not to send massive amounts of data
   delay(1000); 
}

4. end

Give yourself to busy , What you get is steadiness , But it's not true . – 《 No ask seton hall 》