Weather Station with BME280 and Wind Speed and Direction Sensors.

1#include <LiquidCrystal.h>  // for LCD
2#include <Wire.h>
3#include <Adafruit_Sensor.h>
4#include <Adafruit_BME280.h>
5#include <string.h>
6
7// Temperature sensor LCD pins
8#define LCD_RS_PIN 2 
9#define LCD_E_PIN  3
10#define LCD_D4_PIN 4 
11#define LCD_D5_PIN 6  
12#define LCD_D6_PIN 7 
13#define LCD_D7_PIN 8 
14
15// Wind data LCD pins
16#define LCD_RS_PIN_wind 13
17#define LCD_E_PIN_wind 11
18#define LCD_D4_PIN_wind 12 
19#define LCD_D5_PIN_wind 10 
20#define LCD_D6_PIN_wind 9
21#define LCD_D7_PIN_wind A3
22
23// Wind sensors pins
24#define windPin A0  
25#define dirPin  A1  
26
27
28unsigned long previous_time_temp_check = 0;
29unsigned long previous_time_wind_check = 0;
30
31
32unsigned int temp_array_count = 0;
33char temp_array[96];
34
35unsigned int pres_array_count = 0;
36int pres_array[96];
37
38unsigned int wind_speed_array_count = 0;
39char wind_speed_array[300];
40
41unsigned int wind_direction_array_count = 0;
42int wind_direction_array[60];
43
44// This is the amount that we will subtract from the voltage
45float voltage_offset = 0.14;
46
47
48// Create BME280 object for I2C
49Adafruit_BME280 bme;
50
51// Create LCD object
52LiquidCrystal lcd(LCD_RS_PIN, LCD_E_PIN, LCD_D4_PIN, LCD_D5_PIN, LCD_D6_PIN, LCD_D7_PIN);
53LiquidCrystal lcd_wind(LCD_RS_PIN_wind, LCD_E_PIN_wind, LCD_D4_PIN_wind, LCD_D5_PIN_wind, LCD_D6_PIN_wind, LCD_D7_PIN_wind);
54
55
56
57void setup() {
58  Serial.begin(9600);
59
60  lcd.begin(20, 4);  
61  lcd_wind.begin(20, 4);  
62 
63
64  Serial.println(F("BME280 I2C Test"));
65
66// Filling the array with values that are less than what could be in the temp. 
67// This is so when the computer calculates the high and low it won’t use garbage 
68// values that are automatically put into the array. That’s why I used -100.
69  for(int i = 0; i < 96; i++){
70    temp_array[i] = -50;
71  }
72
73  // same as for the temp array
74  for(int i = 0; i < 96; i++){
75    pres_array[i] = 100;
76  }
77
78  for(int i = 0; i < 300; i++){
79    wind_speed_array[i] = 0;
80  }
81
82  // test to initialize the sensor
83  if (!bme.begin(0x76)) { // Use 0x76 (most modules) or 0x77 if needed
84    Serial.println(F("Could not find a valid BME280 sensor, check wiring!"));
85    while (1); // Stop here
86  }
87
88  // initial setup
89  lcd.setCursor(0, 0);
90  lcd.print(F("The temperature will show in 30 seconds"));
91  delay(30000); // to let the sensor stabilize before reading
92//----------------------------------------------------------------------------------------------------------------------
93  int temp = bme.readTemperature();
94  lcd.setCursor(0, 0);
95  lcd.print(F("                    "));
96  lcd.setCursor(0, 0);
97  lcd.print(F("Temp = "));  
98  lcd.print(temp);
99  lcd.print((char)223);
100//--------------------------------------------------------------------------------------------------------------------------
101  float stationPressure = bme.readPressure() / 100.0; // BME280 gives Pa, convert to hPa
102  int altitude = 410; // meters
103  // I'm using int because I don't want the decimal place.
104  unsigned int seaLevelPressure = stationPressure * pow((1 - (altitude / 44330.0)), -5.255);
105  lcd.setCursor(0, 1);
106  lcd.print(F("                    "));
107  lcd.setCursor(0, 1); 
108  lcd.print(F("Pres = "));  
109  lcd.print(seaLevelPressure);  
110  lcd.print(F(" hPa"));
111
112//-------------------------------------------------------------------------------------------------------------------------
113
114  unsigned int humidity = bme.readHumidity();
115  lcd.setCursor(0, 2);
116  lcd.print(F("                    "));
117  lcd.setCursor(0, 2); 
118  lcd.print(F("Humidity = "));  
119  lcd.print(humidity);  
120  lcd.print(F("%")); 
121
122}
123
124void loop() {
125  unsigned long time_now = millis(); // Get the current time
126
127  if(time_now - previous_time_wind_check > 1000){
128    
129    // ===== Wind speed =====
130    int analog_from_speed = analogRead(windPin);         // 0–1023
131    float voltage_from_speed = analog_from_speed / 204.6 - voltage_offset; // 1023/5 ≈ 204.6 for each volt
132    // voltage_offset is an amount you want to subtract from the raw volts, because the sensor is not 0 when it is
133    // not moving and you want it to be 0. To fix that you use the offset.
134           
135    int wind_kmph = voltage_from_speed * 12 * 3.6; // 5V -> 60 m/s => 12 m/s per volt then * 3.6 -> km/h
136
137    // Puts the wind speed value in the right array slot
138    int array_wind_place = wind_speed_array_count % 300;
139    wind_speed_array[array_wind_place] = wind_kmph;
140    wind_speed_array_count++;
141
142    // // this is only for testing the array place
143    // Serial.println("array place wind");
144    // Serial.println(array_wind_place);
145
146    // This will only be accurate 5 minutes after start    
147    
148    int wind_average = 0;
149
150    for(int i = 0; i < 300; i++){
151      wind_average += wind_speed_array[i];
152    } 
153    wind_average /= 300;
154
155    // //for testing
156    // Serial.println("wind average");
157    // Serial.println(wind_average);
158
159    if(wind_kmph < 5){
160      lcd_wind.setCursor(0, 0);
161      lcd_wind.print(F("                    "));
162      lcd_wind.setCursor(0, 0);
163      lcd_wind.print(F("Wind is light")); 
164    }else{
165      lcd_wind.setCursor(0, 0);
166      lcd_wind.print(F("                    "));      
167      lcd_wind.setCursor(0, 0);
168      lcd_wind.print(F("Wind Speed: "));  
169      lcd_wind.print(wind_kmph);
170      lcd_wind.print(F("km"));
171    }
172      lcd_wind.setCursor(0, 1);
173      lcd_wind.print(F("                    "));      
174      lcd_wind.setCursor(0, 1);
175      lcd_wind.print(F("5M wind avg: "));  
176      lcd_wind.print(wind_average);
177      lcd_wind.print(F("km"));
178
179      lcd_wind.setCursor(0, 3);
180      lcd_wind.print(F("V:")); 
181      lcd_wind.print(voltage_from_speed, 2); 
182
183
184    // Print results on serial for testing
185    // Serial.print("Raw ADC: ");
186    // Serial.print(rawSpeed);
187    // Serial.print(" | Voltage: ");
188    // Serial.print(voltSpeed, 2);
189    //Serial.print(F("Wind Speed: "));
190    // Serial.print(windMs, 2);
191    // Serial.print(" m/s (");
192    //Serial.print(wind_kmph);
193    //Serial.print(F(" km/h)"));
194
195
196    // ===== Wind direction =====
197    int analog_from_direction = analogRead(dirPin);            // 0–1023
198    float volts_from_direction = analog_from_direction / 204.6;           
199    int wind_direction = (volts_from_direction / 5.0) * 360.0;    
200
201    int North = 0;
202    int Northeast = 0;
203    int East = 0;
204    int Southeast = 0;
205    int South = 0;
206    int Southwest = 0;
207    int West = 0;
208    int Northwest = 0;
209
210    int array_place_direction = wind_direction_array_count % 60;
211    wind_direction_array[array_place_direction] = wind_direction;
212    wind_direction_array_count++;
213
214    for(int i = 0; i < 60; i++){
215      int test = wind_direction_array[i];
216      if(test > 341){
217        North++;
218      }
219      else if(test < 30){
220        Northeast++;
221      }
222      else if(test < 70){
223        East++;
224      }
225      else if(test < 130){
226        Southeast++;
227      }
228      else if(test < 180){
229        South++;
230      }
231      else if(test < 230){
232        Southwest++;
233      }
234      else if(test < 280){
235        West++;
236      }
237      else if(test < 340){
238        Northwest++;
239      }
240    }
241
242char direction[3] = "--";   // 2 letters max + null terminator
243
244// Checking which is the biggest.
245if (North > Northeast && North > East && North > Southeast && North > South && North > Southwest && North > West && North > Northwest) {
246    strcpy(direction, "N");
247}
248else if (Northeast > North && Northeast > East && Northeast > Southeast && Northeast > South && Northeast > Southwest && Northeast > West && Northeast > Northwest) {
249    strcpy(direction, "NE");
250}
251else if (East > North && East > Northeast && East > Southeast && East > South && East > Southwest && East > West && East > Northwest) {
252    strcpy(direction, "E");
253}
254else if (Southeast > North && Southeast > Northeast && Southeast > East && Southeast > South && Southeast > Southwest && Southeast > West && Southeast > Northwest) {
255    strcpy(direction, "SE");
256}
257else if (South > North && South > Northeast && South > East && South > Southeast && South > Southwest && South > West && South > Northwest) {
258    strcpy(direction, "S");
259}
260else if (Southwest > North && Southwest > Northeast && Southwest > East && Southwest > Southeast && Southwest > South && Southwest > West && Southwest > Northwest) {
261    strcpy(direction, "SW");
262}
263else if (West > North && West > Northeast && West > East && West > Southeast && West > South && West > Southwest && West > Northwest) {
264    strcpy(direction, "W");
265}
266else if (Northwest > North && Northwest > Northeast && Northwest > East && Northwest > Southeast && Northwest > South && Northwest > Southwest && Northwest > West) {
267    strcpy(direction, "NW");
268}
269
270    lcd_wind.setCursor(0, 2);
271    lcd_wind.print(F("                    "));      
272    lcd_wind.setCursor(0, 2);
273    lcd_wind.print(F("wind direction: "));  
274    lcd_wind.print(direction);
275 
276  
277    // // This is just for testing
278    // Serial.print("  ||  Dir Raw: ");
279    // Serial.print(rawDir);
280    // Serial.print(" | Dir Volt: ");
281    // Serial.print(voltDir, 2);
282    // Serial.print(F("Wind Direction: "));
283    // Serial.print(wind_direction);
284    // Serial.println(F(" deg"));
285
286
287    previous_time_wind_check += 1000;
288  }
289  
290  
291  if (time_now - previous_time_temp_check > 900000){
292
293
294// ------------------------------------------------------------------------------------------------------------------------
295  int temp = bme.readTemperature();
296
297  lcd.setCursor(0, 0);
298  lcd.print(F("                    "));
299  lcd.setCursor(0, 0);
300  lcd.print(F("Temp = "));  
301  lcd.print(temp);  
302  lcd.print((char)223);
303
304  // // Testing to see that the count works in serial
305  // Serial.println(F("temp array count"));
306  // Serial.println(temp_array_count);
307
308  // places the temp value in the right array slot
309  int array_place = temp_array_count % 96;
310  temp_array[array_place] = temp;
311  temp_array_count++;
312
313  // // this is only for testing the array place
314  // Serial.println(F("array place temp"));
315  // Serial.println(array_place);
316 
317  // This whole chunk is for the high and low function
318  int high_temp = temp_array[0];
319  int low_temp = temp_array[0];
320
321  for(int i = 0; i < 96; i++){
322
323    if(temp_array[i] < low_temp && temp_array[i] != -50){
324      low_temp = temp_array[i];
325    }
326    else if(temp_array[i] > high_temp){
327      high_temp = temp_array[i];
328    }
329  }
330
331  lcd.setCursor(12, 0);
332  lcd.print(F("H"));  
333  lcd.print(high_temp); 
334  lcd.print(F(" L"));
335  lcd.print(low_temp);
336
337//--------------------------------------------------------------------------------------------------------------------------
338
339  // This gets the pressure and turns the station pressure into sea level pressure
340  float station_pressure = bme.readPressure() / 100.0; // BME280 gives Pa, convert to hPa
341  int altitude = 410; // meters
342  // I'm using int because I don't want the decimal place.
343  unsigned int sea_level_pressure = station_pressure * pow((1 - (altitude / 44330.0)), -5.255);
344
345  lcd.setCursor(0, 1); 
346  lcd.print(F("Pres = "));  
347  lcd.print(sea_level_pressure);  
348  lcd.print(F(" hPa")); 
349
350  // Array placement
351  unsigned char array_place_pres = pres_array_count % 96;
352  pres_array[array_place_pres] = sea_level_pressure;
353  pres_array_count++;
354
355  // // This is just for testing
356  // Serial.println(F("pressure array place"));
357  // Serial.println(pres_array_count);
358  // Serial.println(F("array place presser"));
359  // Serial.println(F("array place pressure"));
360 
361
362  unsigned int high_pres = pres_array[0];
363  unsigned int low_pres = pres_array[0];
364
365  for(int i = 0; i < 96; i++){
366    if(pres_array[i] < low_pres && pres_array[i] != 100){
367      low_pres = pres_array[i];
368    }
369    else if(pres_array[i] > high_pres){
370      high_pres = pres_array[i];
371    }
372  }
373
374  lcd.setCursor(0, 2);
375  lcd.print(F("                    "));
376  lcd.setCursor(0, 2); 
377  lcd.print(F("HP"));  
378  lcd.print(high_pres);  
379  lcd.print(F(" LP")); 
380  lcd.print(low_pres); 
381
382//------------------------------------------------------------------------------------------------------------------------
383  // humidity check
384  // the int is so there should be no decimal
385  int humidity = bme.readHumidity();
386  lcd.setCursor(0, 3); 
387  lcd.print(F("Humidity = "));  
388  lcd.print(humidity);  
389  lcd.print(F("%"));   
390
391// -----------------------------------------------------------------------------------------------------------------------
392  previous_time_temp_check += 900000;
393  }
394}
395
396  
397  // lcd.setCursor(0, 3); 
398  // lcd.print("Altitude = ");  
399  // lcd.print(bme.readAltitude(SEALEVELPRESSURE_HPA));  
400  // lcd.print(" m");