Internet of Things is a system of multiple inter-related computing devices. The factor ‘thing’ in IoT is designated to an entity capable of communicating data over a network (IOT), which can be a digital machine, sensor, human being, animals etc. Each component that is included in IoT network is assigned with an unique identity called UID and the ability to communicate data over IoT network without any external human or computer intervention.
Hello readers, I hope you all are doing great. In our previous tutorial, we discussed how to upload data to Firebase Real-time Database using ESP32. In this tutorial, we will learn how to read the data stored on the Firebase Database with ESP32.
We can access the data stored in Firebase database from anywhere in the world, which makes this preferable in IoT applications.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | ESP32 | Amazon | Buy Now | |
In our previous tutorial, we learnt how to upload an integer value (for demonstration) to Firebase real-time database. So, in this tutorial we will learn how to fetch or receive those integer values from Firebase database.
To access real-time data, we are using two ESP boards where one is used to upload/store the real-time data to the Firebase database and another to read the data stored on the firebase.
Although, it is not required to use two ESP boards, we can also access the previously saved data on the Firebase database with only a single ESP32/ESP8266 board.
We can use the same code for both ESP32 and ESP8266 but we need to make some changes like some of the libraries will be different for ESP8266 and the selection of ESP8266 development board while uploading the code with Arduino IDE.
Fig. 1 Reading data from firebase
Google's Firebase real-time database is a development platform that includes a number of services for managing and authenticating data.
Firebase is a mobile and web app development platform (that also works well with Android APIs) that includes features such as Firebase Cloud, real-time data, and Firebase authentication, among others.
According to Firebase's official documentation (https://firebase.google.com/docs/database), when a user creates a cross-platform application using JavaScript SDKs for Android or Apple, all clients share a single database.
Fig. 1 Firebase Real-time database and ESP32
The following are the main features of the Firebase Real-time database:
The Internet of Things, also known as IoT, is the interconnection of physical objects or devices with sensors and software accessing capabilities in order to communicate data or information over the internet.
We need an interface medium that can fetch, control, and communicate data between sender and receiver electronics devices or servers in order to build an IoT network.
The Firebase real-time database gives you a place to store data from sensors on your level device. With Android APIs, Firebase performs admirably.
Firebase is especially useful for storing data from sensors and syncing it between users in real-time in data-intensive Internet of things (IoT) applications. For the sake of simplicity and clarity, we can say that it is a Google cloud service for real-time collaborative apps.
We are using Arduino IDE to compile and upload code into the ESP32 module. You must have ESP32 board manager installed on your Arduino IDE to program the ESP32 module. To know more about Arduino IDE and how to use it, follow our previous tutorial i.e., on ESP32 programming series. The link is given below:
https://www.theengineeringprojects.com/2021/11/introduction-to-esp32-programming-series.html
Fig. 2 manage libraries
Fig. 3 Install Firebase ESP Client Library
We have already posted a tutorial on our website on getting started with Firebase real-time database and how to post or upload data to Firebase database from ESP32. Where we discussed, how to create a project on Firebase real-time database, authentication, how to access the API key and project URL etc.
So now we do not need to create a new project, we are using the same project and hence same API key and project URL to read or download the data from Firebase real-time database.
Fig. 4 Project Setting
Fig. 5 Project API key
Fig. 6 Project URL
//--add necessary header files
#include <WiFi.h>
#include <Firebase_ESP_Client.h>
#include "addons/TokenHelper.h" //Provide the token generation process info.
#include "addons/RTDBHelper.h" //Provide the real-time database payload printing info and other helper functions.
// Insert your network credentials
#define WIFI_SSID "ssid"
#define WIFI_PASSWORD "password"
// Insert Firebase project API Key
#define API_KEY "replace this with your project API key"
// ----Insert real-time database URL
#define DATABASE_URL "replace this with your project URL"
//Define Firebase Data object
FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;
unsigned long sendDataPrevMillis = 0;
int read_data;
bool signupSuccess = false;
void setup() {
Serial.begin(115200);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(200);
}
Serial.println();
Serial.print("Connected to... ");
Serial.println(WiFi.localIP());
Serial.println();
// Assigning the project API key
config.api_key = API_KEY;
//Assign the project URL
config.database_url = DATABASE_URL;
/// check signup statue
if (Firebase.signUp(&config, &auth, "", "")) {
Serial.println("ok");
signupSuccess = true;
}
else {
Serial.printf("%s\n", config.signer.signupError.message.c_str());
}
// Assign the callback function for token generation task
config.token_status_callback = tokenStatusCallback;
Firebase.begin(&config, &auth);
Firebase.reconnectWiFi(true);
}
void loop()
{
if (Firebase.ready() && signupSuccess && (millis() -
sendDataPrevMillis > 8000 || sendDataPrevMillis == 0))
{
sendDataPrevMillis = millis();
if (Firebase.RTDB.getInt(&fbdo, "/test/int"))
{
if (fbdo.dataType() == "int")
{
read_data = fbdo.intData();
Serial.print("Data received: ");
Serial.println(read_data); //print the data received from the Firebase database
}
}
else
{
Serial.println(fbdo.errorReason()); //print he error (if any)
}
}
}
Fig. 7 Header files
Fig. 8 Helper libraries
Fig. 9 Insert API key
Fig. 10 RTDB URL
Fig. 11 Firebase Data Objects
Fig. 12 Enter Network credentials
Fig. 13 Initialize wifi module
Fig. 14 Fetch/obtain the IP address
Fig. 15 configuring API key
Fig. 16 configuring database URL
Fig. 17 sign up status
Fig. 18
Fig. 19 Fetch data from Firebase RTDB
Fig. 20
Fig. 21 Select development board and COM port
Fig. 22 Data sent Vs Data Received
This concludes the tutorial. I hope you found this of some help and also hope to see you soon with a new tutorial on ESP32.
Hello readers, I hope you all are doing great. In this tutorial, we will learn how to access Firebase (a real-time database) to store and read values or data with ESP32.
It is Google’s mobile application development platform that can be used to can access, monitor and control ESP32 from anywhere in the world with its (firebase) real-time database.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | ESP32 | Amazon | Buy Now | |
Firebase real-time database is a development platform provided by Google which included multiple services to manage and authenticate data.
Firebase is basically a mobile and web app development platform I as works great with Android APIs) that includes features like firebase cloud, real-time data and Firebase authentication etc.
As per Firebase’s official documentation (https://firebase.google.com/docs/database), whenever a user creates a cross-platform application like with Android, or Apple, JavaScript SDKs, all the clients share a single.
Fig. 1 Firebase Real-time database and ESP32
The main features of the Firebase Real-time database are:
The IoT or Internet of Things is the interconnection of physical objects or devices with sensors and software accessing capabilities to communicate data or information over the internet.
To build an IoT network, we need an interface medium that can fetch, control, and communicate data between sender and receiver electronics devices or servers.
Firebase real-time database provides a platform to store data collected from sensors at the level device. Firebase works great with Android APIs.
Firebase is particularly useful in data-intensive Internet of things (IoT) applications to store from sensors and synch that data between users in real-time. For simplicity or better understanding we can say that it is a cloud service provided by Google for real-time collaborative apps.
The steps involved in creating a Firebase project are:
Fig. 2 Get started
Fig. 3 Create a project
Fig. 4 project name
Fig. 5 Enabling Google Analytics
Fig. 6 Project Created successfully
As per the official firebase documentation at: https://firebase.google.com/docs/auth , the identity of a user is required by most online services or mobile applications or we can say , it handles authentication process and logging in (in this tutorial, the ESP32). Getting to know the identity of a user enables an application to save user data securely in the cloud and provide a consistent personalized service across all of the customer's devices (android phones, computers, applications etc).
Fig. 7 Authentication
Fig. 8 Select authentication method
Next thing is creating a real-time database for the project.
Fig. 9 Real-time database
Fig. 10 Creating database
Fig. 11
Fig. 12 select location
Fig. 13 Accessing project API key
We are using Arduino IDE to compile and upload code into the ESP32 module. You must have the ESP32 board manager installed on your Arduino IDE to program the ESP32 module. To know more about Arduino IDE and how to use it, follow our previous tutorial i.e., on ESP32 programming series. The link is given below:
https://www.theengineeringprojects.com/2021/11/introduction-to-esp32-programming-series.html
Steps to add the necessary libraries in Arduino IDE:
Fig. 14 manage libraries
Fig. 15 Install Firebase ESP Client Library
//--add necessary header files
#include <WiFi.h>
#include <Firebase_ESP_Client.h>
#include "addons/TokenHelper.h" //Provide the token generation process info.
#include "addons/RTDBHelper.h" //Provide the real-time database payload printing info and other helper functions.
// Insert your network credentials
#define WIFI_SSID "replace this with your netwrok SSID"
#define WIFI_PASSWORD "replace this with your wi-fi password"
// Insert Firebase project API Key
#define API_KEY "replace this with your API key"
// ----Insert real-time database URL
#define DATABASE_URL "replace this with your project URL"
//----Define Firebase Data object
FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;
int value = 10;
bool signupSuccess = false;
unsigned long sendDataPrevMillis = 0;
void setup()
{
Serial.begin(115200);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Serial.print("Connecting to Wi-Fi");
while (WiFi.status() != WL_CONNECTED){
Serial.print(".");
delay(100);
}
Serial.println();
Serial.print("Connected with IP: ");
Serial.println(WiFi.localIP() );
Serial.println();
// Assign the api key ( required)
config.api_key = API_KEY;
// Assign the RTDB URL ( required)
config.database_url = DATABASE_URL;
// Sign up status
if (Firebase.signUp(&config, &auth, "", ""))
{
Serial.println("ok");
signupSuccess = true;
}
else{
Serial.printf("%s\n", config.signer.signupError.message.c_str());
}
/* Assign the callback function for the long running token generation task */
config.token_status_callback = tokenStatusCallback; // see addons/TokenHelper.h
Firebase.begin(&config, & auth);
Firebase.reconnectWiFi( true);
}
void loop()
{
if (Firebase.ready() && signupSuccess && (millis() - sendDataPrevMillis >
10000 || sendDataPrevMillis == 0))
{
sendDataPrevMillis = millis();
if (Firebase.RTDB.setInt(&fbdo, "test/int", value))
{
Serial.println("PASSED");
Serial.println("PATH: " + fbdo.dataPath());
Serial.println("TYPE: " + fbdo.dataType());
}
else
{
Serial.println("FAILED");
Serial.println("REASON: " + fbdo.errorReason());
}
value++;
}
}
Before uploading the code in ESP32 board there are some changes you need to make which includes:
Fig. 16 Header files
Fig. 17 Helper libraries
Fig. 18 Insert API key
Fig. 19 RTDB URL
Fig. 20 Firebase Data Objects
Fig. 21 Enter Network credentials
Fig. 22 variable declaration
Fig. 23 Initialize wifi module
Fig. 24 Fetch/obtain the IP address
Fig. 25 configuring API key
Fig. 26 configuring database URL
Fig. 27 sign up status
Fig. 28
Fig. 29 Loop() function
Fig. 30 Select development board and COM port
Fig. 31 Result 1
Fig. 32 Result 2
This concludes the tutorial. I hope you found this of some help and also hope to see you soon with a new tutorial on ESP32.