Temperature and Moisture Sensors with Alert

RiverTrue Jan 21.2022

0 8604 Medium

We used temperature and moisture sensors on a plant. If the temperature is too high or the moisture is too low, the light will alert you.

Things used in this project

Hardware components

HARDWARE LIST

1 DFRobot Gravity: Analog Capacitive Soil Moisture Sensor- Corrosion Resistant

Link

1 DHT11 Temperature & Humidity Sensor (4 pins)

3 Particle Argon

1 RGB Diffused Common Cathode

1 Adafruit Standard LCD - 16x2 White on Blue

Story

In this project, we use a moisture sensor, a temperature/humidity sensor, and an RGB light to detect moisture and temperature levels. If the soil moisture is too low, the RBG light will blink red. If the temperature is too high, since a higher temperature will dry out the soil quicker, the RGB light will blink green.

This solves the problem of people not knowing when to water their plants, and prevents the problem of overwatering plants. This device is useful because it will remind you automatically, instead of having to remember yourself. Somebody would want this because it will help keep their plants watered and help prevent overwatering their plants. This project is novel because it combines the moisture and temperature sensors instead of them being on their own, along with an alert, so it is quite a lot in one device. Our newly acquired IOT skills allow us to program the sensor to do all of the things that it does. Without them, the sensors would only work by themselves, and not work in unison to create this unique device.

Schematics

Assembled Project Picture

Temperature Sensor Picture

Moisture Sensor Picture

RGB Light Picture

Project Flow Chart

Temperature Sensor Circuit Diagram

Moisture Sensor Circuit Diagram

RBG Circuit Diagram

Code

This code is collecting the moisture data from the plant and publishing it to the particle cloud. It also compares the moisture percentage do a threshold value to determine whether the moisture is too, and if it is publishes an alert called "MoistureAlert". This code goes on the Argon with the moisture sensor.

CODE

int boardLed = D7; 

int moisture_pin = A1; 

const static float moisture_threshold = 25.00;



void setup() {
  pinMode(boardLed,OUTPUT); 
  pinMode(moisture_pin,INPUT);  


  
  digitalWrite(boardLed,HIGH);
  delay(200);
  digitalWrite(boardLed,LOW);
  delay(200);

}




void loop() {
    

    digitalWrite(boardLed,HIGH);
   
    int moisture_analog = analogRead(moisture_pin); // read capacitive sensor
    float moisture_percentage = (100 - ( (moisture_analog/4095.00) * 100 ) );
    if(BATT > 1){
        float voltage = analogRead(BATT) * 0.0011224;
        Particle.publish("plantStatus_voltage", String(voltage),60,PUBLIC);
    }
   
    Particle.publish("plantStatus_analog", String(moisture_analog),60,PUBLIC);
    Particle.publish("plantStatus_percentage", String(moisture_percentage),60,PUBLIC);
    digitalWrite(boardLed,LOW);
    
    delay(30000);
    
    
  String data = String(10);
  // Trigger the integration
  Particle.publish("plantStatus_percentage", data, PRIVATE);
  // Wait 30 seconds
  delay(30000);
  
   if (moisture_percentage < moisture_threshold){
        Particle.publish("MoistureAlert");
    }
    
}

Temperature Data Collection

C/C++

This is the code for collecting temperature data in the area around the plant. If the temperature or humidity gets to high, an event is published to the cloud called "TempAlert". This code goes on the Argon with the temperature sensor.

CODE

// This #include statement was automatically added by the Particle IDE.
#include <DHT.h>

// This #include statement was automatically added by the Particle IDE.
#include <Adafruit_Sensor.h>

// This #include statement was automatically added by the Particle IDE.
#include <LiquidCrystal.h>

// This #include statement was automatically added by the Particle IDE.
#include <LiquidCrystal.h>
//int rs=D0;
//int en=D1;
//int d4=D2;
//int d5=D3;
//int d6=D4;
//int d7=D5;
LiquidCrystal lcd (D0,D1,D2,D3,D4,D5);

// This #include statement was automatically added by the Particle IDE.
#include <DHT.h>

//2-Colours LED Pins
int led1 = D8; //Connect the D8 pins on particle argon to R-pin on RGB LED. Red-LED
int sensepin=6;
DHT HT(sensepin, DHT11);
float humidity;
float tempC;
float tmepF;
int setTime = 1000;
int dt=2000;
const static float temp_threshold = 8.00;

void setup() {
    Serial.begin(9600);
    HT.begin();
    delay(setTime);
lcd.begin (16,2);
pinMode(led1, OUTPUT);
}

void loop() {

humidity=HT.readHumidity();
tempC=HT.readTemperature ();
tmepF=HT.readTemperature(true);




lcd.setCursor(0,0);
lcd.print("Temp F=");
lcd.print(String(tmepF));

lcd.setCursor(0,1);
lcd.print("humidity = ");
lcd.print(String(humidity));
lcd.print("%");



Serial.print ("Humidity:  ");
Serial.print (humidity);
Serial.print ("Temperature C ");
Serial.print (tempC);
Serial.print ("C");
Serial.print (tmepF);
Serial.print ("F");

  // Get some data
  String data = String((10));
  // Trigger the integration
  Particle.publish("Temp/humidity", data, PRIVATE);
  // Wait 30 seconds
  delay(5000);
  
  if(tempC > temp_threshold){
      Particle.publish("TempAlert");
}
}

LED Response

C/C++

This is the code that triggers the LED's to light up. If the 'MoistureAlert' event is published the red LED turns on on. If the "TempAlert" event is published the green LED is turned on. This code goes on the Argon that is connected to the LED.

CODE

int redled = D8;
int yellowled = D7;
void setup() {
    
    pinMode(redled, OUTPUT);
    pinMode(yellowled, OUTPUT);
    digitalWrite(redled, LOW);
    digitalWrite(yellowled, LOW);
    
    Particle.subscribe("MoistureAlert", blinkred);
    Particle.subscribe("TempAlert", blinkyellow);
}


void blinkred(const char *event, const char *data){ 
    digitalWrite(redled, HIGH);
    delay(2000);
    digitalWrite(redled,LOW);
}

void blinkyellow(const char *event, const char *data){ 
    digitalWrite(yellowled, HIGH);
    delay(2000);
    digitalWrite(yellowled, LOW);
}

void loop() {
    
}

The article was first published in hackster, April 22, 2021

cr: https://www.hackster.io/group-31/temperature-and-moisture-sensors-with-alert-42d2af

author: Team Group 31: Zachary Bellflower, Xavier, Ash Rai

License

All Rights

Reserved