Arduino Nano ESP32 - Water Leak Email Notification
This guide will show you how to use Arduino Nano ESP32 to detect water leaks and immediately send email alerts. We will explain how to set up the sensor, provide code examples, and demonstrate how to link with email services. This is useful for keeping your home or office protected from water damage and is ideal for those who like DIY projects and want to enhance their water leak detection systems.
Hardware Preparation
Or you can buy the following kits:
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
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Additionally, some of these links are for products from our own brand, DIYables .
Overview of Water Sensor and Gmail
We provide clear guides on Water Sensors and Gmail. Each guide includes detailed instructions and simple steps on setting up the hardware, understanding how it works, and connecting and programming the Arduino Nano ESP32. To find out more, please click these links.
- Arduino Nano ESP32 - Gmail tutorial
Wiring Diagram between Water Sensor and Arduino Nano ESP32
This image is created using Fritzing. Click to enlarge image
Arduino Nano ESP32 Code
/*
* This Arduino Nano ESP32 code was developed by newbiely.com
*
* This Arduino Nano ESP32 code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-nano-esp32/arduino-nano-esp32-water-leak-email-notification
*/
#include <WiFi.h>
#include <ESP_Mail_Client.h>
#define WIFI_SSID "YOUR_WIFI_SSID" // CHANGE IT
#define WIFI_PASSWORD "YOUR_WIFI_PASSWORD" // CHANGE IT
// the sender email credentials
#define SENDER_EMAIL "xxxxxx@gmail.com" // CHANGE IT
#define SENDER_PASSWORD "xxxx xxxx xxxx xxxx" // CHANGE IT to your Google App password
#define RECIPIENT_EMAIL "xxxxxx@gmail.com" // CHANGE IT
#define SMTP_HOST "smtp.gmail.com"
#define SMTP_PORT 587
#define WATER_SENSOR_PIN D4 // The Arduino Nano ESP32 pin D4 connected to water sensor's pin
int water_state; // current state of water sensor
int prev_water_state; // previous state of water sensor
SMTPSession smtp;
void setup() {
Serial.begin(9600);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(300);
}
Serial.println();
Serial.print("Connected with IP: ");
Serial.println(WiFi.localIP());
Serial.println();
pinMode(WATER_SENSOR_PIN, INPUT_PULLUP); // set ESP32 pin to input pull-up mode
water_state = digitalRead(WATER_SENSOR_PIN); // read state
}
void loop() {
prev_water_state = water_state; // save the last state
water_state = digitalRead(WATER_SENSOR_PIN); // read new state
if (prev_water_state == HIGH && water_state == LOW) {
Serial.println("Water leakage is detected!");
String subject = "Email Notification from ESP32";
String textMsg = "This is an email sent from ESP32.\n";
textMsg += "Water leakage is detected";
gmail_send(subject, textMsg);
}
}
void gmail_send(String subject, String textMsg) {
// set the network reconnection option
MailClient.networkReconnect(true);
smtp.debug(1);
smtp.callback(smtpCallback);
Session_Config config;
// set the session config
config.server.host_name = SMTP_HOST;
config.server.port = SMTP_PORT;
config.login.email = SENDER_EMAIL;
config.login.password = SENDER_PASSWORD;
config.login.user_domain = F("127.0.0.1");
config.time.ntp_server = F("pool.ntp.org,time.nist.gov");
config.time.gmt_offset = 3;
config.time.day_light_offset = 0;
// declare the message class
SMTP_Message message;
// set the message headers
message.sender.name = F("ESP32");
message.sender.email = SENDER_EMAIL;
message.subject = subject;
message.addRecipient(F("To Whom It May Concern"), RECIPIENT_EMAIL);
message.text.content = textMsg;
message.text.transfer_encoding = "base64";
message.text.charSet = F("utf-8");
message.priority = esp_mail_smtp_priority::esp_mail_smtp_priority_low;
// set the custom message header
message.addHeader(F("Message-ID: <abcde.fghij@gmail.com>"));
// connect to the server
if (!smtp.connect(&config)) {
Serial.printf("Connection error, Status Code: %d, Error Code: %d, Reason: %s\n", smtp.statusCode(), smtp.errorCode(), smtp.errorReason().c_str());
return;
}
if (!smtp.isLoggedIn()) {
Serial.println("Not yet logged in.");
} else {
if (smtp.isAuthenticated())
Serial.println("Successfully logged in.");
else
Serial.println("Connected with no Auth.");
}
// start sending Email and close the session
if (!MailClient.sendMail(&smtp, &message))
Serial.printf("Error, Status Code: %d, Error Code: %d, Reason: %s\n", smtp.statusCode(), smtp.errorCode(), smtp.errorReason().c_str());
}
// callback function to get the Email sending status
void smtpCallback(SMTP_Status status) {
// print the current status
Serial.println(status.info());
// print the sending result
if (status.success()) {
Serial.println("----------------");
Serial.printf("Email sent success: %d\n", status.completedCount());
Serial.printf("Email sent failed: %d\n", status.failedCount());
Serial.println("----------------\n");
for (size_t i = 0; i < smtp.sendingResult.size(); i++) {
// get the result item
SMTP_Result result = smtp.sendingResult.getItem(i);
Serial.printf("Message No: %d\n", i + 1);
Serial.printf("Status: %s\n", result.completed ? "success" : "failed");
Serial.printf("Date/Time: %s\n", MailClient.Time.getDateTimeString(result.timestamp, "%B %d, %Y %H:%M:%S").c_str());
Serial.printf("Recipient: %s\n", result.recipients.c_str());
Serial.printf("Subject: %s\n", result.subject.c_str());
}
Serial.println("----------------\n");
// free the memory
smtp.sendingResult.clear();
}
}
Detailed Instructions
To get started with Arduino Nano ESP32, follow these steps:
- If you are new to Arduino Nano ESP32, refer to the tutorial on how to set up the environment for Arduino Nano ESP32 in the Arduino IDE.
- Connec the water sensor to the Arduino Nano ESP32 board according to the provided diagram.
- Connect the Arduino Nano ESP32 board to your computer using a USB cable.
- Launch the Arduino IDE on your computer.
- Select the Arduino Nano ESP32 board and its corresponding COM port.
- Open the Library Manager by clicking Library Manager icon on the left side of the Arduino IDE.
- Search for ESP Mail Client and locate the ESP Mail Client by Mobizt.
- Click on the Install button to get the ESP Mail Client library.
- Copy the provided code and paste it into the Arduino IDE.
- Change your WiFi credentials details by editing WIFI_SSID and WIFI_PASSWORD in the code.
- Put your email and password in place of the sender's by updating SENDER_EMAIL and SENDER_PASSWORD.
- Edit the recipient's email address in the code by changing RECIPIENT_EMAIL. It can be the same as the sender’s email.
※ NOTE THAT:
- The sender's email must be a Gmail account.
- Use the App password from the previous step as the sender’s password.
- The recipient’s email can be any type of email.
- Click the Upload button in Arduino IDE to send the code to Arduino Nano ESP32.
- Open the Serial Monitor.
- Pour water onto the water sensor.
- Check the Serial Monitor to see the result.
8
Serial.println("Hello World!");
Message (Enter to send message to 'Arduino Nano ESP32' on 'COM15')
New Line
9600 baud
Water leakage is detected
#### Email sent successfully
> C: Email sent successfully
----------------
Message sent success: 1
Message sent failed: 0
----------------
Message No: 1
Status: success
Date/Time: May 27, 2024 04:42:50
Recipient: xxxxxx@gmail.com
Subject: Email Notification from Arduino Nano ESP32
----------------
- Look in your email inbox. You should get an email similar to this:
