This tutorial of Robo India explains the building of smart rooftop garden using moisture sensor .
1. Introduction:
It is a NodeMCU based automatic plant watering system that uses a soil moisture sensor.
2. Required Hardware
Following Hardware will be required :
| S.No. | Item | Quantity |
| 1 | NodeMCU | 1 |
| 2 | Breadboard | 1 |
| 3 | Soil Moisture Sensor | 1 |
| 4 | Solenoid valve | 1 |
| 5 | Relay | 1 |
| 6 | Step Down Transformer | 1 |
| 7 | NPN Transistor | 1 |
3. Building Circuit
Make the following connections –
(1) Connections with Soil Moisture
(2) Block Diagram of whole circuit-
For Blynk Setup :
(1)Open App and create a new Project
(2)Add Five widgets 2-Numeric Input, Labeled Value, Button,Notification
(3)Add Maximum and Minimum in Numeric Input widgets.
4. Programming
You may download this NodeMCU Sketch from here.
#define BLYNK_PRINT Serial
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <WiFiClient.h>
#include <ThingSpeak.h>
String apiKey = "...."; //apiKey from Thingspeak
BlynkTimer timer;
char auth[] = "...."; //auth token from blynk app
int minData=550;
int maxData=40;
int LEDV= 0;
int sensorState ;
const char* server = "api.thingspeak.com";
WiFiClient client;
BLYNK_WRITE(V1) //Button Widget is writing to pin V1
{
minData = param.asInt();
}
BLYNK_WRITE(V2) //Button Widget is writing to pin V1
{
maxData = param.asInt();
}
BLYNK_WRITE(V5) //Button Widget is writing to pin V1
{
LEDV = param.asInt();
if(LEDV ==0)
digitalWrite(4,LOW);
else
digitalWrite(4,HIGH);
}
BLYNK_READ(V4)
{
Blynk.virtualWrite(V4,sensorState);
}
void sendSensor()
{
sensorState = analogRead(A0);
Serial.println(sensorState);
if (sensorState < minData)
{ if(LEDV!=HIGH)
{ Serial.println("needs water, send notification");
//Blynk.notify("Water your plants");
BLYNK_READ(V4);
}
}
else if (sensorState >= maxData&&LEDV==HIGH )
{
Serial.println("does not need water");
digitalWrite(4,LOW);
Blynk.notify(" pump switched off");
Blynk.virtualWrite(V5,LOW);
LEDV=0;
}
else
{
Serial.println("all Good");
}
if (client.connect(server,80)) // "184.106.153.149" or api.thingspeak.com
{
String postStr = apiKey;
postStr +="&field3=";
postStr += String(sensorState);
postStr += "\r\n\r\n";
client.print("POST /update HTTP/1.1\n");
client.print("Host: api.thingspeak.com\n");
client.print("Connection: close\n");
client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
client.print("Content-Type: application/x-www-form-urlencoded\n");
client.print("Content-Length: ");
client.print(postStr.length());
client.print("\n\n");
client.print(postStr);
Serial.print(" Moisture ");
Serial.print(sensorState);
Serial.print("\n\n");
}
client.stop();
}
void setup()
{
Serial.begin(9600);
Blynk.begin(auth, "....", "...."); //wifi name and password
pinMode(4, OUTPUT);
timer.setInterval(2000L,sendSensor);
}
void loop()
{
Blynk.run();
timer.run();
}
6. Output:
If you have any query please write us at support@roboindia.com
Thanks and Regards
Content Development Team
Robo India
https://roboindia.com