Temperature and Humidity with Min/Max on LCD

1/*
2  Temperature and Humidity with Min and Max
3
4  Displays current temperature along with minimum and maximum readings.
5
6  Most Arduinos have an on-board LED on pin 13 that you can control. 
7  On the UNO, MEGA and ZERO it is attached to digital pin 13, 
8  on MKR1000 on pin 6. This LED is used as a status for LCD display.
9  Just before the LCD display changes it will blink once.
10
11  For this example, the DHT11 temperature and humidity module is used.
12 The data pin from the DHT11 module is connected to analog pin A0.
13
14  For the display, a generic 16x2 LCD display is attached to an I2C.
15  The Vcc and GND from the I2C is connected to the ICSP header.
16
17  Written by Jesse Leon
18 */
19
20#include <dht.h>                     // Load the DHT module library
21#include <LiquidCrystal_I2C.h>       // Lod the LCD with I2C library
22LiquidCrystal_I2C lcd(0x27, 16, 2);  // Initialize LCD on address 2x27 with a 16 x 2 display
23#define dht_pin A0                   // Analog Pin A0 of Arduino is connected to DHT11 out pin
24dht DHT;                             // Set alias
25byte myTemp;                         // Variable used to store current temperature in Celsius
26byte myHumid;                        // Variable used to store current humidity
27byte minHumid;                       // Variable used to store minimum humidity
28byte maxHumid;                       // Variable used to store maximum humidity
29byte minTemp;                        // Variable used to store minimum temperature
30byte maxTemp;                        // Variable used to store maximum temperature
31byte converted;                      // Variable used to store converted temperature from Celsius to Fahrenheit
32byte CminTemp;                       // Variable used to store converted minimum temperature
33byte CmaxTemp;                       // Variable used to store converted maximum temperature
34int ledStatus = 13;                  // Initiate pin 13 as ledStatus
35
36void setup() {
37  pinMode(ledStatus, OUTPUT);     // Set pin mode for status LED
38  digitalWrite(ledStatus, HIGH);  // Turn on status LED
39  lcd.init();                     // Initialize I2C LCD display
40  lcd.backlight();                // Turn on LCD back light
41  lcd.clear();                    // Clear the LCD screen
42
43  /* The following section is optional
44  ====================================================================================*/
45  lcd.setCursor(0, 0);               // Set LCD cursor to 1st position on first line
46  lcd.print(F("TEMP & HUMIDITY "));  // Send text to LCD
47  lcd.setCursor(0, 1);               // Set LCD cursor to 1st position on 2nd line
48  lcd.print(F("Initializing    "));  // Send text to LCD
49  delay(500);                        // Set delay
50  lcd.setCursor(0, 1);               // Set LCD cursor to 1st position on 2nd line
51  lcd.print(F("Initializing.   "));  // Send text to LCD
52  delay(500);                        // Set delay
53  lcd.setCursor(0, 1);               // Set LCD cursor to 1st position on 2nd line
54  lcd.print(F("Initializing..  "));  // Send text to LCD
55  delay(500);                        // Set delay
56  lcd.setCursor(0, 1);               // Set LCD cursor to 1st position on 2nd line
57  lcd.print(F("Initializing... "));  // Send text to LCD
58  delay(500);                        // Set delay
59  lcd.setCursor(0, 1);               // Set LCD cursor to 1st position on 2nd line
60  lcd.print(F("Initializing...."));  // Send text to LCD
61  /*====================================================================================
62  End of optional section */
63
64  DHT.read11(dht_pin);              // Read data from dht_pin (A0)
65  delay(500);                       // Set delay
66  minHumid = (DHT.humidity);        // Set variable to initial minimum humidity reading
67  maxHumid = (DHT.humidity);        // Set variable to initial maximum humidity reading
68  minTemp = (DHT.temperature);      // Set variable to initial minimum temperature reading
69  CminTemp = (minTemp * 1.8) + 32;  // Convert minimum temperature reading to Fahrenheit
70  maxTemp = (DHT.temperature);      // Set variable to initial minimum temperature reading
71  CmaxTemp = (maxTemp * 1.8) + 32;  // Convert maximum temperature reading to Fahrenheit
72  digitalWrite(ledStatus, LOW);     // Turn off status LED
73}
74
75void loop() {
76  DHT.read11(dht_pin);              // Take new reading from module
77  myHumid = (DHT.humidity);         // Set variable to current humidity reading
78  myTemp = (DHT.temperature);       // Set variable to current temperature reading
79  converted = (myTemp * 1.8) + 32;  // set variable to converted temperature in Fahrenheit
80
81  if (myHumid < minHumid) { minHumid = (DHT.humidity); }  // If current humidity is < minimum, set minimum to current
82  if (myHumid > maxHumid) { maxHumid = (DHT.humidity); }  // If current humidity is > maximum, set maximum to current
83  if (converted < CminTemp) { CminTemp = converted; }     // If current temperature is < minimum, set maximum to current
84  if (converted > CmaxTemp) { CmaxTemp = converted; }     // If current temperature is > maximum, set maximum to current
85
86  TempStat();   // Run TempStat function
87  delay(5000);  // wait for delay
88  HumidStat();  // Run HumidStat function
89  delay(5000);  // wait for delay
90}
91
92void TempStat() {
93  digitalWrite(ledStatus, HIGH);  // Turn on status LED
94  lcd.setCursor(0, 0);            // Set LCD cursor position
95  lcd.print(F("TEMP   min: "));   // Display message on LCD
96  lcd.setCursor(12, 0);           // Set LCD cursor position
97  lcd.print(CminTemp);            // Display minimum temperature on LCD
98  lcd.print(F(" F"));             // Display message on LCD
99  lcd.setCursor(0, 1);            // Set LCD cursor position
100  lcd.print(converted);           // Display current temperature on LCD
101  lcd.print(F(" F   "));          // Display message on LCD
102  lcd.setCursor(7, 1);            // Set LCD cursor position
103  lcd.print(F("max: "));          // Display message on LCD
104  lcd.setCursor(12, 1);           // Set LCD cursor position
105  lcd.print(CmaxTemp);            // Display maximum temperature on LCD
106  lcd.print(F(" F"));             // Display message on LCD
107  digitalWrite(ledStatus, LOW);   // Turn off status LED
108}
109
110void HumidStat() {
111  digitalWrite(ledStatus, HIGH);  // Turn on status LED
112  lcd.setCursor(0, 0);            // Set LCD cursor position
113  lcd.print(F("HUMID  min: "));   // Display message on LCD
114  lcd.setCursor(12, 0);           // Set LCD cursor position
115  lcd.print(minHumid);            // Display minimum humidity on LCD
116  lcd.print(F(" %"));             // Display message on LCD
117  lcd.setCursor(0, 1);            // Set LCD cursor position
118  lcd.print(myHumid);             // Display current humidity on LCD
119  lcd.print(F(" %  "));           // Display message on LCD
120  lcd.setCursor(7, 1);            // Set LCD cursor position
121  lcd.print(F("max: "));          // Display message on LCD
122  lcd.setCursor(12, 1);           // Set LCD cursor position
123  lcd.print(maxHumid);            // Display maximum humidity on LCD
124  lcd.print(F(" %"));             // Display message on LCD
125  digitalWrite(ledStatus, LOW);   // Turn off status LED
126}