Temperature and Humidity on OLED Easy

1//DHT sensor
2#include "DHT.h"
3#define DHT11Pin 2
4#define DHTType DHT11
5//OLED
6#include  <Wire.h>
7#include <Adafruit_GFX.h>
8#include <Adafruit_SSD1306.h>
9
10DHT  HT(DHT11Pin,DHTType);
11float humi;
12float tempC;
13float tempF;
14
15//OLED  define
16#define SCREEN_WIDTH 128 //OLED display width, in pixels
17#define SCREEN_HEIGHT  64 //OLED display height, in pixels
18//SSD1306 display connected  to I2C (SDA, SCL pins)
19Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT,  &Wire, -1);
20
21void setup() {
22  Serial.begin(9600);
23  //For DHT11
24  HT.begin();
25  //Necessary code for OLED I2C
26  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C))  { // Address 0x3D for 128x64
27    Serial.println(F("SSD1306 allocation failed"));
28    for(;;);
29  }
30  display.display(); //Displays the starting logo
31  delay(1000); 
32  display.clearDisplay();
33}
34
35void loop() {
36 delay(1000);
37 humi =  HT.readHumidity();
38 tempC = HT.readTemperature();
39 tempF = HT.readTemperature(true);
40
41 display.clearDisplay();
42  oledDisplayHeader();
43 //configures the position of the readings. (charactersize, x axis value, y axis value, reading, symbol)
44oledDisplay(2,90,28,humi,"%");
45 oledDisplay(3,-10,44,tempC,"C");
46  oledDisplay(3,-10,16,tempF,"F");
47
48 display.display(); 
49 
50}
51
52void  oledDisplayHeader(){
53  //configures position and qualities of headers
54 display.setTextSize(1);
55 display.setTextColor(WHITE);
56  display.setCursor(0, 0);
57 display.print("Temperature");
58 display.setCursor(80,  0);
59 display.print("Humidity");
60}
61void oledDisplay(int size, int x,int  y, float value, String unit){
62 int charLen=18;
63 int xo=x+charLen*3.2;
64  int xunit=x+charLen*3.6;
65 int xval = x; 
66 display.setTextSize(size);
67 display.setTextColor(WHITE);
68  
69 if (unit=="%"){
70   display.setCursor(x, y);
71   display.print(value,0);
72   display.print(unit);
73 } else {
74   if (value>99){
75    xval=x;
76   }  else {
77    xval=x+charLen;
78   }
79   display.setCursor(xval, y);
80   display.print(value,0);
81   display.drawCircle(xo, y+2, 2, WHITE);  // print degree symbols
82   display.setCursor(xunit,  y);
83   display.print(unit);
84 }
85 
86}