The Idea
Problem
Solution
Parts
Goals
Working
Coding
Blynk Part
The Project Is Complete
Finishing
Conclusion

Published January 25, 2019 © GPL3+

Smart Irrigation

Automatic and smart care of plants by proper watering and their monitoring.

IntermediateFull instructions provided2 hours3,913

Things used in this project

Hardware components

Espressif Wemos D1 Mini

WIFI MCU

Infineon CoolMOS C7 Gold SJ MOSFET

A very good quality and efficient DC MOSFET.

Adafruit Waterproof DS18B20 Digital temperature sensor

for measuring soil temperature.

SparkFun Soil Moisture Sensor (with Screw Terminals)

measuring soil moisture.

Software apps and online services

Blynk

The IOT app

Arduino IDE

Coding IDE..

Hand tools and fabrication machines

Soldering iron (generic)

Well if you want to actually make it..

Story

The Idea:

To make the irrigation system in gardens, farms and backyards more smart and automatic. Also to monitor the soil conditions.

Problem:

I have observed many a times that in some parks, water is not given properly to plants. There is overwatering (like a lot) at some plaes and completely dry (where vegetation dies) in some other. Across the Globe. almost 30% of irrigation water is wasted in over watering. To solve that I planned to make a device that controls the irrigating system properly. So that there is no over watering and all plants get the "required" amount of water.

Solution:

To solve this problem we can make a Internet connected device that controls he irrigation system. For better controls we need to also monitor the temperature as soil temps above 35C are also harmful for plants. And by watering little water we can reduce the temps. For Soil Moisture, a generic sensor can do the Job but a capacitive one is recommended.

Parts:

Wemos D1 Mini // Small IOT device // Main MCU

Soil Moisture Sensor

DS18B20 temp. sensor // for soil temperature // along with 4.7kOhm Resistor if not inbuilt

A good MOSFET- Infineon CoolMos MOSFET // for DC switching // Most Irrigating Motors/ Pumps/ Solenoids operate in DC // And it has less V drop. // and less current to run.

1 / 3 • Soil Moisture Sensor

The wiring scheme (schematics) have been attached below.

Goals:

To keep the soil moisture appropriate to plant’s requirement.
No need to worry of plant’s wilting when no one’s there to water your plants.

Working:

The Soil Temperature and Moisture sensor data is read by the MCU which sends that data to Blynk Cloud (the easiest and quickest tool). Then we can see the data on our smartphones with Blynk App and its Eventor Widget (the best one for me) easily can check the conditions and we can do the switching (of water) job without long code.

Coding:

Connect your MCU to PC and do all installation of boards and Arduino IDE (google search is good for that info) and upload the code attached. The code is very self Explanatory and simple. Just don't forget to install Bkynk and Dallas Library.

Blynk Part:

Download and Open Blynk App and create your account to get Auth Token you enter in the code. Then configure your "App" something like this:

You can change the widgets and tabs etc..

And get Eventor Widget and do conditions something like this:

You can change the settings

You can also add Email and Phone Notifications.

Don't forget to change soil moisture values, because it is different for each soil, sensor and calibration method.

Don't Forget to make your device waterproof, but hot gluing a box, or using simple plastic bag (like I did).

The Project Is Complete!

Finishing:

If you want a permanent setup, solder the pieces together or get a custom PCB. There are some chances of Improvement, if not using Internet, Main one being the code, which needs to do the condition checking with simple "ifs" locally.

1 / 3 • I just put it in soil upside down as I realised that I had put Soil Moisure Sensor on wring side.

Conclusion:

The project works. I took it to several parks to test it out and it works there as well with little adjustments.

The CoolMos MOSFET works really well. To switch AC two of them can be used (but I used on 12V DC instead of max 600V for safety concern). It consumed less current than a relay so can be directly addressed from a even 3.3V MCU (though I don't know how did it work). Overall, being so small CoolMos SJ MOSFET is silent, efficient and reliable for its work.

Code

Smart Gardening

#include <OneWire.h>
#include <DallasTemperature.h>
#define ONE_WIRE_BUS D1
OneWire oneWire(ONE_WIRE_BUS);
/********************************************************************/
// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);

#define BLYNK_PRINT Serial


#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "<enter your auth token generated>";

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "SSID";
char pass[] = "password for ssid";


BlynkTimer timer;

// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void myTimerEvent()
{
  sensors.requestTemperatures();
  float t = sensors.getTempCByIndex(0);
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
  Blynk.virtualWrite(V5, t);
  Blynk.virtualWrite(V7,analogRead(A0));
}

void setup()
{
  Serial.begin(9600);

  Blynk.begin(auth, ssid, pass);
  // You can also specify server:
  //Blynk.begin(auth, wifi, ssid, pass, "blynk-cloud.com", 8442);
  //Blynk.begin(auth, wifi, ssid, pass, IPAddress(192,168,1,100), 8442);
  sensors.begin();
  // Setup a function to be called every second
  timer.setInterval(5000L, myTimerEvent);
}

void loop()
{
  Blynk.run();
  timer.run(); // Initiates BlynkTimer
}

Credits

Vimarsh

5 projects • 38 followers

Currently, a student studying Physics @ BITS Pilani. A maker and a learner :D

Smart Irrigation