Mini Weather Station Using Arduino Nano

1#include <SPI.h>               //include Serial Peripheral Interface library
2#include  <Wire.h>              //include Two Wire Interface library
3#include <Adafruit_GFX.h>      // include Adafruit graphics library
4#include <Adafruit_ST7735.h>   //  include Adafruit ST7735 TFT library
5#include <Adafruit_BMP280.h>   // include  Adafruit BMP280 sensor library
6#include "DHT.h"               //include DHTXX  sensor library
7#define DHTPIN 2               //DHT11 data pin connected to arduino  pin D2
8#define DHTTYPE DHT11          //specifying the type of DHT sensor used
9#define  TFT_RST   8            // TFT RST pin is connected to arduino pin D8
10#define  TFT_CS    10           // TFT CS  pin is connected to arduino pin D9
11#define  TFT_DC    9            // TFT DC  pin is connected to arduino pin D10
12// initialize  ST7735 SERIES TFT library
13Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC,  TFT_RST);
14 
15// define device I2C address: 0x76 or 0x77 (0x77 is the library  default address)
16#define BMP280_I2C_ADDRESS  0x76
17 
18Adafruit_BMP280  bmp280;       // initialize Adafruit BMP280 library
19DHT dht(DHTPIN, DHTTYPE);      //  initialize DHT sensor
20 
21void setup(void)
22{
23  dht.begin();                                         //  synchronizing DHT sensor
24  tft.initR(INITR_144GREENTAB);                        //  initialize a ST7735S chip, black tab
25  tft.fillScreen(ST77XX_BLACK);                        //  setting black background
26  tft.drawFastHLine(0, 15 ,  tft.width(), ST77XX_CYAN);//  draw horizontal seperation line at position (0, 15)
27 
28  tft.setTextColor(ST77XX_CYAN,  ST77XX_BLACK);         // set text color to white and black background
29  tft.setTextSize(1);                                  // setting text size to 1
30  //tft.setCursor(4,  0);                               // move cursor to position (4, 0) pixel
31  //tft.print("ARDUINO  + ST7735 TFT");
32  tft.setCursor(25, 5);                                // move  cursor to position (25, 5) pixel
33  tft.print("WEATHER BUDDY");
34 
35  //  initialize the BMP280 sensor
36  if( bmp280.begin(BMP280_I2C_ADDRESS) == 0 )
37  {  // connection error or device address wrong!
38    tft.setTextColor(ST77XX_RED,  ST77XX_CYAN);         // set text color to red and black background
39    tft.setTextSize(2);                                // setting text size to 2
40    tft.setCursor(5,  76);                              // move cursor to position (5, 76) pixel
41    tft.print("Connection");
42    tft.setCursor(35, 100);                            // move cursor to position  (35, 100) pixel
43    tft.print("Error");
44    while(1);  // stay here
45  }
46 
47  tft.drawFastHLine(0, 55,  tft.width(), ST77XX_CYAN);  // draw horizontal  seperation line at position (0, 55)pixel
48  tft.drawFastHLine(0, 95,  tft.width(),  ST77XX_CYAN);  // draw horizontal seperation line at position (0, 195)pixel
49  tft.setTextColor(ST77XX_RED, ST77XX_BLACK);           // set text color to red  and black background
50  tft.setCursor(30, 20);                                //  move cursor to position (30, 20) pixel
51  tft.print("TEMPERATURE ");                            //  setting heading for first section
52  tft.setTextColor(ST77XX_CYAN, ST77XX_BLACK);          // set text color to cyan and black background
53  tft.setCursor(40,  60);                                // move cursor to position (40, 60) pixel
54  tft.print("HUMIDITY ");                               // setting heading for  second section
55  tft.setTextColor(ST77XX_GREEN, ST7735_BLACK);         // set  text color to green and black background
56  tft.setCursor(40, 100);                               //  move cursor to position (40, 100) pixel
57  tft.print("PRESSURE ");                               //  setting heading for third section 
58  tft.setTextSize(2);                                   //  setting text size to 2 
59}
60 
61// main loop
62void loop()
63  {
64
65  char _buffer[8];
66  // read temperature, humidity and pressure from the BMP280  sensor
67  float temp = bmp280.readTemperature();    // get temperature in °C
68  float hum = dht.readHumidity();           // get humidity in rH%
69  float pres  = bmp280.readPressure();       // get pressure in hPa
70 
71  // print temperature  (in °C)
72  if(temp < 0)                              // if temperature < 0
73    sprintf( _buffer, "-%02u.%02u", (int)abs(temp), (int)(abs(temp) * 100) % 100  );
74  else                                      // if temperature >= 0
75    sprintf(  _buffer, " %02u.%02u", (int)temp, (int)(temp * 100) % 100 );// setting the value  approximation 
76  tft.setTextColor(ST77XX_YELLOW, ST77XX_BLACK);  // set text  color to yellow and black background
77  tft.setCursor(11, 34);                          //  move cursor to position (11,34) pixel 
78  tft.print(_buffer);                             //  print temperature from BMP-280 sensor
79  tft.drawCircle(89, 34, 2, ST77XX_YELLOW);       // print the degree symbol ( ° )(can be omitted if * is used instead)
80  tft.setCursor(95, 34);                          // move cursor to position (95,34)  pixel 
81  tft.print("C");                                 // print the Celcius  symbol     
82 
83  // 2: print humidity (in %)
84  sprintf( _buffer, "%02u  ", (int)(hum));          // setting the value approximation 
85  tft.setTextColor(ST77XX_MAGENTA,  ST77XX_BLACK);  // set text color to magenta and black background
86  tft.setCursor(45,  74);                           // move cursor to position (45,74) pixel
87  tft.print(_buffer);                              // print humidity from DHT-11 sensor
88  tft.setCursor(75,  74);                           // move cursor to position (75,74) pixel
89  tft.print("%");                                  // print the percentage symbol     
90 
91 
92  // 3: print pressure (in hPa)
93  sprintf( _buffer, "%04u.%02u", (int)(pres/100),  (int)((uint32_t)pres % 100) ); // setting the value approximation 
94  tft.setTextColor(ST77XX_ORANGE,  ST77XX_BLACK);  // set text color to orange and black background
95  tft.setCursor(3,  112);                          // move cursor to position (3,112)pixel      
96  tft.print(_buffer);                             // print atmospheric pressure  from BMP-280
97  tft.setCursor(91, 112);                         // move cursor  to position (91,112)pixel
98  tft.print("hPa");                               //  print unit of atmospheric pressure as hecto pascal
99 
100  delay(1000);                                    //  wait 1 second before taking next sensor reading
101 
102}