Weather station with BME280 and OLED screen

1/*This code is about a weather station consisting of an Arduino Nano, BME280, OLED 128x64 and a pushbutton.
2Sensor BME280 and OLED screen are connected with I2C protocol. Library <ezButton> is used for checking pushbutton.  
3Measurements are made every 10 seconds and the values are rounded.
4Starting screen is temperature and if you press button once display shows humidity. One more press and display shows pressure.
5With the next press display shows sequentially for three seconds temperature, after humidity and at the end pressure.
6If we press one more time pushbutton displays begins showing temperature again.
7
8*/
9
10#include <Wire.h>
11#include <Adafruit_GFX.h>
12#include <Adafruit_SSD1306.h>
13#include <Adafruit_Sensor.h>
14#include <Adafruit_BME280.h>
15#include <ezButton.h>
16
17
18float temp;      //VARIABLE FOR MEASURING TEMPERATURE
19float hum;       //VARIABLE FOR MEASURING HUMIDITY
20float pressure;  //VARIABLE FOR MEASURING PRESSURE
21
22float roundtemp;    //VARIABLE FOR ROUNDING TEMPERATURE
23float roundhum;     //VARIABLE FOR ROUNDING HUMIDITY
24int roundpressure;  //VARIABLE FOR ROUNDING PRESSURE
25
26int i = 0;  //VARIABLE HELPING FOR AUTO SEQUENCE DISPLAY
27
28unsigned long prevTime = 0;
29long intervalSample = 10000;  //TIME PERIOD FOR MEASURING TEMPERATURE, HUMIDITY, PRESSURE
30
31unsigned long prevT2 = 0;
32long intervalShow = 3000;  //TIME PERIOD FOR SHOWING MEASUREMENTS IN SEQUENCE
33
34
35int toprint = 0;  //VARIABLE FOR SELECTING WHAT TO PRINT ON OLED SCREEN
36                  //0 = TEMP  1=HUM   2=PRESSURE  3=AUTO SEQUENCE
37
38
39ezButton button1(6);  // create ezButton object that attach to pin 6;
40
41#define SCREEN_WIDTH 128  // OLED display width, in pixels
42#define SCREEN_HEIGHT 64  // OLED display height, in pixels
43
44
45#define OLED_RESET -1  // Reset pin # (or -1 if sharing Arduino reset pin)
46Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
47
48Adafruit_BME280 bme;  // I2C
49                      //Adafruit_BMP280 bme(BMP_CS); // hardware SPI
50                      //Adafruit_BMP280 bme(BMP_CS, BMP_MOSI, BMP_MISO,  BMP_SCK);
51
52void setup() {
53
54  button1.setDebounceTime(50);  // set debounce time to 50 milliseconds
55
56  if (!bme.begin()) {
57    Serial.println("Could not find a valid BMP280 sensor, check wiring!");
58    while (1)
59      ;
60  }
61
62
63  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
64  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {  // Address 0x3D for 128x64
65    Serial.println(F("SSD1306 allocation failed"));
66    for (;;)
67      ;  // Don't proceed, loop forever
68  }
69  display.display();  //display initial Adafruit logo
70
71  delay(2000);
72
73  // Clear the buffer
74  display.clearDisplay();
75  display.display();
76}
77
78void loop() {
79
80  button1.loop();  // MUST call the loop() function first
81  unsigned long currentTime = millis();
82
83  if (currentTime - prevTime >= intervalSample) {  //GET MEASUREMENTS EVERY 10 SECONDS
84
85    hum = bme.readHumidity();  //READ, STORE AND ROUND HUMIDITY
86    delay(10);
87    hum = hum + 0.05;
88    hum = hum * 10;
89    int newhum = (int)hum;
90    roundhum = (float)newhum / 10;
91
92    temp = bme.readTemperature();  //READ, STORE AND ROUND TEMPERATURE
93    delay(10);
94    temp = temp + 0.05;
95    temp = temp * 10;
96    int newtemp = (int)temp;
97    roundtemp = (float)newtemp / 10;
98    
99    pressure = bme.readPressure() / 100;  //READ, STORE AND ROUND BAROMETRIC PRESSURE
100    delay(10);
101    pressure = pressure + 0.5;
102    roundpressure = (int)pressure;
103    prevTime = currentTime;
104  }
105
106  if (button1.isPressed())  //CHECK IF BUTTON IS PRESSED
107    toprint = toprint + 1;
108  if (toprint == 4) {
109    toprint = 0;
110  }
111
112  switch (toprint) {
113    case 0:
114      standartext();
115      temperaturetext();  //PRINT TEMPERATURE
116      display.clearDisplay();
117      break;
118
119    case 1:
120      standartext();
121      humiditytext();  //PRINT HUMIDITY
122      display.clearDisplay();
123      break;
124
125    case 2:
126      standartext();
127      pressuretext();  //PRINT BAROMETRIC PRESSURE
128      display.clearDisplay();
129      break;
130
131    case 3:
132      if (i == 0) {
133        standartext();
134        humiditytext();  //PRINT HUMIDITY
135        display.clearDisplay();
136      }
137
138      if (i == 1) {
139        standartext();
140        temperaturetext();  //PRINT TEMPERATURE
141        display.clearDisplay();
142      }
143
144      if (i == 2) {
145        standartext();
146        pressuretext();  //PRINT PRESSURE
147        display.clearDisplay();
148      }
149      if (currentTime - prevT2 >= intervalShow) {
150        i = i + 1;
151        prevT2 = currentTime;
152        if (i == 3) {
153          i = 0;
154        }
155      }
156      break;
157  }
158}
159
160void standartext() {
161
162  display.fillRect(0, 0, 128, 16, SSD1306_BLACK);
163  display.fillRect(0, 34, 128, 10, SSD1306_WHITE);
164
165  display.setCursor(22, 1);
166  display.setTextSize(2);
167  display.setTextColor(SSD1306_WHITE);
168  display.println("WEATHER");
169
170  display.setCursor(22, 18);
171  display.setTextSize(2);
172  display.setTextColor(SSD1306_WHITE);
173  display.println("STATION");
174}
175
176void temperaturetext() {
177
178  display.setCursor(29, 35);
179  display.setTextSize(1);
180  display.setTextColor(BLACK, WHITE);
181  display.println("Temperature");
182
183  display.setCursor(2, 48);
184  display.setTextSize(2);
185  display.setTextColor(SSD1306_WHITE);
186  display.println("T=");
187
188  display.setCursor(27, 48);
189  display.setTextSize(2);
190  display.setTextColor(SSD1306_WHITE);
191  display.println(roundtemp);
192
193  display.drawCircle(92, 50, 2, WHITE);
194  display.setCursor(97, 48);
195  display.setTextSize(2);
196  display.setTextColor(SSD1306_WHITE);
197  display.println("C");
198
199  display.display();
200}
201
202void humiditytext() {
203
204  display.setCursor(29, 35);
205  display.setTextSize(1);
206  display.setTextColor(BLACK, WHITE);
207  display.println("Humidity     ");
208
209  display.setCursor(2, 48);
210  display.setTextSize(2);
211  display.setTextColor(SSD1306_WHITE);
212  display.println("H=");
213
214  display.setCursor(27, 48);
215  display.setTextSize(2);
216  display.setTextColor(SSD1306_WHITE);
217  display.println(roundhum);
218
219  display.setCursor(92, 48);
220  display.setTextSize(2);
221  display.setTextColor(SSD1306_WHITE);
222  display.println("%");
223
224  display.display();
225}
226
227void pressuretext() {
228
229  display.setCursor(10, 35);
230  display.setTextSize(1);
231  display.setTextColor(BLACK, WHITE);
232  display.println("Barometric pressure");
233
234  display.setCursor(2, 48);
235  display.setTextSize(2);
236  display.setTextColor(SSD1306_WHITE);
237  display.println("P=");
238
239  display.setCursor(27, 48);
240  display.setTextSize(2);
241  display.setTextColor(SSD1306_WHITE);
242  display.println(roundpressure);
243
244  display.setCursor(84, 48);
245  display.setTextSize(2);
246  display.setTextColor(SSD1306_WHITE);
247  display.println("hPa");
248
249  display.display();
250}