 void drawDigit(short value, boolean hasDecimalPoint) {
   switch (value) {
     case R_SYMBOL:
-      digitalWrite(SEGMENT_A_PIN, LOW);
-      digitalWrite(SEGMENT_B_PIN, LOW);
-      digitalWrite(SEGMENT_C_PIN, LOW);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, HIGH);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case E_SYMBOL:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, LOW);
-      digitalWrite(SEGMENT_C_PIN, LOW);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, HIGH);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case NOTHING_SYMBOL:
-      digitalWrite(SEGMENT_A_PIN, LOW);
-      digitalWrite(SEGMENT_B_PIN, LOW);
-      digitalWrite(SEGMENT_C_PIN, LOW);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, LOW);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_OFF);
       break;
     case HUMIDITY_SYMBOL:
-      digitalWrite(SEGMENT_A_PIN, LOW);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, HIGH);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case DEGREE_SYMBOL:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, LOW);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case MINUS_SYMBOL:
-      digitalWrite(SEGMENT_A_PIN, LOW);
-      digitalWrite(SEGMENT_B_PIN, LOW);
-      digitalWrite(SEGMENT_C_PIN, LOW);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case 0:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, HIGH);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, LOW);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_OFF);
       break;
     case 1:
-      digitalWrite(SEGMENT_A_PIN, LOW);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, LOW);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_OFF);
       break;
     case 2:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, LOW);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, HIGH);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case 3:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case 4:
-      digitalWrite(SEGMENT_A_PIN, LOW);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case 5:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, LOW);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case 6:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, LOW);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, HIGH);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case 7:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, LOW);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_OFF);
       break;
     case 8:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, HIGH);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     case 9:
-      digitalWrite(SEGMENT_A_PIN, HIGH);
-      digitalWrite(SEGMENT_B_PIN, HIGH);
-      digitalWrite(SEGMENT_C_PIN, HIGH);
-      digitalWrite(SEGMENT_D_PIN, HIGH);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, HIGH);
-      digitalWrite(SEGMENT_G_PIN, HIGH);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_ON);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_ON);
       break;
     default:
-      digitalWrite(SEGMENT_A_PIN, LOW);
-      digitalWrite(SEGMENT_B_PIN, LOW);
-      digitalWrite(SEGMENT_C_PIN, LOW);
-      digitalWrite(SEGMENT_D_PIN, LOW);
-      digitalWrite(SEGMENT_E_PIN, LOW);
-      digitalWrite(SEGMENT_F_PIN, LOW);
-      digitalWrite(SEGMENT_G_PIN, LOW);
-  }
-  digitalWrite(SEGMENT_DP_PIN, hasDecimalPoint ? HIGH : LOW);
+      digitalWrite(SEGMENT_A_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_B_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_C_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_D_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_E_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_F_PIN, SEGMENT_OFF);
+      digitalWrite(SEGMENT_G_PIN, SEGMENT_OFF);
+  }
+  digitalWrite(SEGMENT_DP_PIN, hasDecimalPoint ? SEGMENT_ON : SEGMENT_OFF);
 }
 
 int readData() {

  analogWrite(DIGIT_2_PIN, DIGIT_OFF);
  analogWrite(DIGIT_3_PIN, DIGIT_OFF);
  analogWrite(DIGIT_4_PIN, DIGIT_OFF);
  digitalWrite(SEGMENT_A_PIN, HIGH);
  digitalWrite(SEGMENT_B_PIN, HIGH);
  digitalWrite(SEGMENT_C_PIN, HIGH);
  digitalWrite(SEGMENT_D_PIN, HIGH);
  digitalWrite(SEGMENT_E_PIN, HIGH);
  digitalWrite(SEGMENT_F_PIN, HIGH);
  digitalWrite(SEGMENT_G_PIN, HIGH);
  digitalWrite(SEGMENT_DP_PIN, HIGH);
  
  startModeMillis = millis();
  lastReadingMillis = startModeMillis;

const int SEGMENT_G_PIN = 13;
const int SEGMENT_DP_PIN = 4;

// LED display with common cathode:
const byte DIGIT_OFF = 255;
const byte DIGIT_ON = 0; // increase the value to reduce current
const byte SEGMENT_OFF = LOW;
const byte SEGMENT_ON = HIGH;
// LED display with common anode:
//const byte DIGIT_OFF = 0;
//const byte DIGIT_ON = 255; // decrease the value to reduce current
//const byte SEGMENT_OFF = HIGH;
//const byte SEGMENT_ON = LOW;

const short MINUS_SYMBOL = -1;
const short DEGREE_SYMBOL = -2;
