Smart Plant Soil Monitor

1#include <Wire.h>
2#include <Adafruit_GFX.h>
3#include <Adafruit_SSD1306.h>
4#include <DHT.h>
5
6// OLED Configuration (I2C: SDA=A4, SCL=A5)
7#define SCREEN_WIDTH 128
8#define SCREEN_HEIGHT 64
9Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
10
11// Pin Definitions
12#define SOIL_MOISTURE_PIN A0   // Soil Moisture Sensor
13#define DHT_PIN 2              // DHT11 Sensor
14#define DHT_TYPE DHT11         // DHT11 Sensor Type
15#define BUZZER_PIN 6           // Buzzer
16
17// Tri-Color LED (Common Anode)
18#define RED_LED 3              // CO1 - Red
19#define GREEN_LED 4            // CO2 - Green
20#define BLUE_LED 5             // CO3 - Blue
21
22// Initialize DHT Sensor
23DHT dht(DHT_PIN, DHT_TYPE);
24
25void setup() {
26    Serial.begin(115200);
27    dht.begin();
28
29    pinMode(SOIL_MOISTURE_PIN, INPUT);
30    pinMode(BUZZER_PIN, OUTPUT);
31    pinMode(RED_LED, OUTPUT);
32    pinMode(GREEN_LED, OUTPUT);
33    pinMode(BLUE_LED, OUTPUT);
34
35    // Initialize OLED Display
36    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
37        Serial.println("OLED Display not found!");
38        while (1);
39    }
40    display.clearDisplay();
41    Serial.println("System Initialized!");
42}
43
44// Function to set LED color
45void setColor(bool red, bool green, bool blue) {
46    digitalWrite(RED_LED, red ? LOW : HIGH);
47    digitalWrite(GREEN_LED, green ? LOW : HIGH);
48    digitalWrite(BLUE_LED, blue ? LOW : HIGH);
49}
50
51void loop() {
52    // Read Raw Soil Moisture Value
53    int moistureValue = analogRead(SOIL_MOISTURE_PIN);
54    Serial.print("Raw Moisture Value: ");
55    Serial.println(moistureValue);
56
57    // Adjust Mapping Based on Real Readings
58    int moisturePercentage = map(moistureValue, 300, 900, 0, 100);
59    moisturePercentage = constrain(moisturePercentage, 0, 100);
60
61    // Read Temperature & Humidity
62    float temperature = dht.readTemperature();
63    float humidity = dht.readHumidity();
64
65    // Check if DHT11 gives valid data
66    if (isnan(temperature) || isnan(humidity)) {
67        Serial.println("DHT11 Sensor Not Found!");
68        display.clearDisplay();
69        display.setTextSize(1);
70        display.setTextColor(WHITE);
71        display.setCursor(10, 20);
72        display.print("DHT11 Not Found!");
73        display.display();
74        delay(2000);
75        return;
76    }
77
78    // Print values in Serial Monitor
79    Serial.print("Moisture: "); Serial.print(moisturePercentage); Serial.println("%");
80    Serial.print("Temperature: "); Serial.print(temperature); Serial.println(" °C");
81    Serial.print("Humidity: "); Serial.print(humidity); Serial.println(" %");
82
83    // Display Sensor Data on OLED
84    display.clearDisplay();
85    display.setTextSize(1);
86    display.setTextColor(WHITE);
87    display.setCursor(10, 10);
88    display.print("Moisture: "); display.print(moisturePercentage); display.println("%");
89    display.setCursor(10, 30);
90    display.print("Temp: "); display.print(temperature); display.println("C");
91    display.setCursor(10, 50);
92    display.print("Humidity: "); display.print(humidity); display.println("%");
93    display.display();
94
95    // LED & Buzzer Alerts
96    if (moisturePercentage < 30 || temperature > 30.0 || temperature < 20.0) {
97        setColor(1, 0, 0);  // 🔴 Red (Critical Condition)
98        digitalWrite(BUZZER_PIN, HIGH);
99    } else if (moisturePercentage < 40) {
100        setColor(0, 0, 1);  // 🔵 Blue (Warning Condition)
101        digitalWrite(BUZZER_PIN, LOW);
102    } else {
103        setColor(0, 1, 0);  // 🟢 Green (Normal Condition)
104        digitalWrite(BUZZER_PIN, LOW);
105    }
106
107    delay(2000);  // Refresh every 2 seconds
108}