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| photo by Kaufmann Mercantile |
It always happens that whenever I go for any vacation, my plants die. Because They don’t get proper care, sunlight, and water. So to avoid that I have created this DIY project which allows me to check my plant's moisture status, even when I am not at home, and also automate watering the plant.
In this project, I am using a moisture sensor that captures soil moisture after every 1 sec and sends it to ESP8266 nodeMCU. I am also using the real-time database of firebase to store this data and get the latest data to compare moisture value with a threshold value. If the moisture value is less than the threshold value, esp8266 node MCU starts the water pump for 5 sec and if the value is higher than the threshold value, it does nothing.
Implementing this DIY project, cost me 500-700 bucks. Below I have mentioned the components required for this project. All these components are available on amazon.
Required Component
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| ESP8266 e-12 |
ESP8266 e-12 NodeMCu development board is very inexpensive system-on-chip (SOC). It has CPU, RAM, and Wifi modules. Pins information of ESP8266 nodeMCU are mentioned below:
| Pin | Description |
|---|---|
| A0 | Analog |
| RSV | Reserved |
| SD0/SD1/SD2/SD3 | SDIO Data |
| CMD | SDIO CMD |
| CLK | Clock |
| GND | Ground |
| 3V3 | 3.3V |
| EN | Chip Enable |
| RST | Reset |
| VIN | 3.3V Regulator |
| TXD | UART TXD |
| RXD | UART RXD |
| D0-D8 | GPIO pins |
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| water pump |
Choose a water pump according to the distance between the water source and plants. I have used a 3-6V water pump because I have kept both water source and plant side by side. I am using a 9V battery, to power the water pump.
Wiring
Connect the -ve pin of the battery to the -ve pin of the water pump and connect the +ve pin of the battery to the middle pin of the relay and +ve connection of the water pump to the open pin of the relay.
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| pump connection with battery and 5V single channel relay |
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| 5V single channel Relay |
Relay is an electro-mechanical component that acts as a switch. On the left-hand side, it has an output terminal, which is connected to AC/DC load. There are 3 pins in the o/p terminal
NC (normal close) - This pin is connected to create a close circuit and its connection break when the signal is sent from the relay signal pin.
COM(Common) pin - This is generally connected with AC/DC load.
NO(normal open) - this pin is generally open and it becomes close when the signal is sent from the relay signal pin
In i/p terminal, which is on the right-hand side has 3 pins - GND, Vcc, and digital pin. In this project, I have connected these pins with ESP8266 GND, 3V3, and D1 pins.
| 5V Relay | ESP8266 NodeMCU |
|---|---|
| GND | GND |
| Vcc | 3V3 |
| inpt 1 | D1 |
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| 3V moisture sensor |
| Moisture Sensor | ESP8266 NodeMCU |
|---|---|
| GND | GND |
| Vcc | 3V3 |
| A0 | A0 |
| D0 |
the following formula is used to calculate soil moisture in percentage:
moisture_value = (100- (analogRead(input_sensor)/1023.00)*100);
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| male and female jumper wires |
You can also use wires instead of jumper wires. But with help of jumper wires, it is very easy to connect with all components.
Schematic Diagram & Connection
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| Schematic diagram of esp8266 connection with moisture sensor and water pump |
Firebase Real-time database
These are the following steps to set up a real-time database in firebase:
1. Sign in to firebase and click on go to the console.
3. Create a new project and continue
4. Disable google analytics
7. Define security rules for your data. For this project, I have selected locked mode and defined read & write condition true
FIREBASE_AUTH key
To access the firebase real-time database in the project requires the FIREBASE_AUTH key. Following are steps to access it:1. Click on the setting icon on the left-hand side and select project-setting.
2. Go to Service Account
3. Select Database secrets
Setup Arduino-Firebase library in Arduino IDE
To make an API call for getting and sending data to the firebase real-time database from ESP8266 nodeMCU, I am using 3rd party library - FirebaseArduino. Download this git repo library as a zip file and add in Arduino IDE:
You can find the library location in File > Preference > Sketch folder
Coding
Copy the following code and execute this in Arduino IDE and upload it in esp8266 nodeMCU
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| #include <ESP8266WiFi.h> | |
| #include <FirebaseArduino.h> //added Firebase Arduino to access realtime database | |
| #include <ArduinoJson.h> //required for get and set api call | |
| #define FIREBASE_HOST " db link" | |
| #define FIREBASE_AUTH "secret key" | |
| #define WIFI_SSID "wifi username" | |
| #define WIFI_PASSWORD "password" | |
| #define relay D1 | |
| //const int relay = 1; | |
| const int input_sensor = A0; //analog pin | |
| void setup() { | |
| Serial.begin(9600); //define baud rate for serial communication | |
| delay(1000); | |
| pinMode(relay,OUTPUT); | |
| WiFi.begin(WIFI_SSID,WIFI_PASSWORD); | |
| while(WiFi.status()!=WL_CONNECTED){ | |
| Serial.print("."); | |
| delay(500); | |
| } | |
| Serial.println("Connected"); | |
| Serial.print("IP Address"); | |
| Serial.println(WiFi.localIP()); | |
| Firebase.begin(FIREBASE_HOST,FIREBASE_AUTH); | |
| Firebase.set("/plant1/humidity", 0); | |
| digitalWrite(relay,HIGH); | |
| } | |
| void loop() { | |
| float moisture_value; | |
| moisture_value = (100- (analogRead(input_sensor)/1023.00)*100); | |
| Serial.println("Soil moisture is - "); | |
| Serial.print(moisture_value); | |
| Serial.println(" %"); | |
| delay(1000); | |
| String value = String(moisture_value); | |
| Firebase.setFloat("/plant1/humidity",moisture_value); | |
| if (Firebase.failed()) | |
| { | |
| Serial.print("firebase2 failed:"); | |
| Serial.println(Firebase.error()); | |
| return; | |
| } | |
| delay(2000); | |
| float plant1 = Firebase.getFloat("/plant1/humidity"); | |
| Serial.print("plant1 humidit: "); | |
| Serial.println(plant1); | |
| if( WiFi.status()== WL_CONNECTED && plant1 >0 && plant1 < 35) | |
| { | |
| digitalWrite(relay,LOW); | |
| Firebase.setInt("/plant1/pump",1); | |
| delay(1000); | |
| Serial.print("pump is high "); | |
| digitalWrite(relay,HIGH); | |
| }else | |
| { | |
| digitalWrite(relay,HIGH); | |
| Firebase.setInt("/plant1/pump",0); | |
| Serial.print("pump is low "); | |
| } | |
| if (Firebase.failed()) | |
| { | |
| Serial.print("firebase3 failed:"); | |
| Serial.println(Firebase.error()); | |
| digitalWrite(relay,HIGH); | |
| return; | |
| } | |
| } |