In this post, we will learn how to send the real-time sensor data to Google Firebase Console using NodeMCU ESP8266 & DHT11 Sensor.
Overview: Send Real-Time Sensor Data to Google Firebase with ESP8266
Earlier when there was no development of IoT, the remote monitoring of sensor data was limited. The device used to be placed near the observer to check the data on display devices. Since the advancement of IoT, the limitations have been removed and data monitoring remotely has been possible. Not only the monitoring of data remotely but also monitoring the data on a real-time basis has become possible.
So we are basically focusing on IoT Based Remote Data Monitoring System. In some of our earlier projects, we used the IoT platforms like Thingspeak, Adafruit.io & Webpage to monitor data remotely using Nodemcu ESP8266. But in this project, we will Send the Real-Time Sensor Data to Google Firebase with ESP8266 & DHT11 Humidity Temperature Sensor. The data will be read using DHT11 Sensor and sent to Google Firebase Console Database.
Google Firebase is a Google-backed application development software used for creating, managing,and modifying data generated from any android/IOS application, web services, IoT sensors & Hardware. To learn more about the Google Firebase Console, you can read the official Google Firebase Documentation from Google Firebase
Bill of Materials
Following are the components required for making this project. All the components can be easily purchased from Amazon. The component purchase link is given below.
| S.N. | Components Name | Quantity | Purchase Links |
|---|---|---|---|
| 1 | NodeMCU ESP8266 Board | 1 | Amazon | AliExpress |
| 2 | DHT11 Sensor | 1 | Amazon | AliExpress |
| 3 | Micro-USB Cable | 1 | Amazon | AliExpress |
| 4 | Jumper Wires | 1 | Amazon | AliExpress |
| 5 | Breadboard | 1 | Amazon | AliExpress |
Setting Up Hardware & NodeMCU DHT11 Circuit
Here is a circuit diagram for connecting DHT11 Humidity Temperature Sensor with NodeMCU ESP8266 Board. Connect the positive terminal of DHT11 to 3.3V & negative terminal to GND. Connect the digital output pin to D2/GPIO4 of NodeMCU.
If you want to learn more about the DHT11 Humidity Temperature Sensor, you can follow this post: Interfacing DHT11 Humidity Temperature Sensor with Arduino
You can assemble the circuit on breadboard as I used a breadboard for Assembly too. You can see the image below.
Now let us learn how we can send Real-Time Sensor Data to Google Firebase with Nodemcu ESP8266.
Installing Libraries
FirebaseArduino is a library to simplify connecting to the Firebase database from Arduino clients. It is a full abstraction of Firebase’s REST API exposed through C++ calls in a wiring friendly way. All JSON parsing is handled by the library and you may deal in pure C/Arduino types.
The library cannot work standalone. So you need to add the ArduinoJSON library as well.
1. ArduinoJSON Library
So first go to the library manager and search for “JSON” & install the library as shown in the figure below.
Note: The latest JSON library might not work with the code. So you may need to downgrade the library to version v5.13.5
2. Google FirebaseExtended Library
Now you need to install Google Firebase library as well. So, download the library from below link and add it to Library folder after extraction.
3. DHT11 Library
To read the temperature and humidity we need any temperature humidity sensor. For that DHT11 is the best and cheap sensor. We need to install DHT11 Library for that. Download the library from below and add to the Arduino IDE.
Setting up Google Firebase Console Database
Now the main thing that we need to do is Setting up Google Firebase Console Database. Once the setup is done, we can then Send Real-Time Sensor Data to Google Firebase with Nodemcu ESP8266.
But I won’t be explaining here how you can set up the Google Firebase Console Database because I have already explained the entire process in the previous tutorial. You can check the following tutorial to learn how to do the setup.
Once the setup is done you will get the following window.
Source Code/Program: Send Sensor Data to Google Firebase with ESP8266
Now the hardware and Google Firebase Setup is done. So lets move to the programming part. So, here is a Source Code/Program to Send Real-Time Sensor Data to Google Firebase with ESP8266. Copy the code and upload it to the NodeMCU ESP8266 Board.
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#define FIREBASE_HOST "mydhtsensor-26aa7.firebaseio.com" #define FIREBASE_AUTH "90*******************************iiL" #define WIFI_SSID "Alexahome" #define WIFI_PASSWORD "12345678" |
Before uploading the code, make sure to do the changes to FIREBASE_AUTH & FIREBASE_HOST. You can get these parameters from Google Firebase Console. Check the previous tutorial to learn more.
Also change the WIFI_SSID & WIFI_PASSWORD from the given code and replace it with your wifi SSID & Password.
Check the complete code here.
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#include <ESP8266WiFi.h> #include <FirebaseArduino.h> #include <DHT.h> #define FIREBASE_HOST "******************.firebaseio.com" #define FIREBASE_AUTH "***********************************" #define WIFI_SSID "***********" #define WIFI_PASSWORD "**************" #define DHTPIN D2 // Digital pin connected to DHT11 #define DHTTYPE DHT11 // Initialize dht type as DHT 11 DHT dht(DHTPIN, DHTTYPE); void setup() { Serial.begin(115200); dht.begin(); //reads dht sensor data WiFi.begin(WIFI_SSID, WIFI_PASSWORD); Serial.print("Connecting to "); Serial.print(WIFI_SSID); while (WiFi.status() != WL_CONNECTED) { Serial.print("."); delay(500); } Serial.println(); Serial.print("Connected"); Serial.print("IP Address: "); Serial.println(WiFi.localIP()); //prints local IP address Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH); // connect to the firebase } void loop() { float h = dht.readHumidity(); // Read Humidity float t = dht.readTemperature(); // Read temperature if (isnan(h) || isnan(t)) // Checking sensor working { Serial.println(F("Failed to read from DHT sensor!")); return; } Serial.print("Humidity: "); Serial.print(h); String fireHumid = String(h) + String("%"); //Humidity integer to string conversion Serial.print("% Temperature: "); Serial.print(t); Serial.println("°C "); String fireTemp = String(t) + String("°C"); //Temperature integer to string conversion delay(5000); Firebase.pushString("/DHT11/Humidity", fireHumid); //setup path to send Humidity readings Firebase.pushString("/DHT11/Temperature", fireTemp); //setup path to send Temperature readings if (Firebase.failed()) { Serial.print("pushing /logs failed:"); Serial.println(Firebase.error()); return; } } |
Code Explanation
First, we include the library for Firebase & DHT11 Sensor
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#include <ESP8266WiFi.h> #include <FirebaseArduino.h> #include <DHT.h> |
Then we define the two parameters FIREBASE_HOST & FIREBASE_AUTH. We get these parameters from Google Firebase Setup. These two parameters are very important to communicate with firebase. This enables the data exchange between the ESP8266 and the firebase.
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#define FIREBASE_HOST "*********************.firebaseio.com" #define FIREBASE_AUTH "********************************" |
Then we define the WiFi SSID & Password. Replace SSID and password with your network SSID and password. The Nodemcu will connect to the network & communicates with Google Firewall.
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#define WIFI_SSID "Alexahome" #define WIFI_PASSWORD "12345678" |
Then we define the DHT Sensor type & create the DHT Sensor instances.
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#define DHTPIN D2 #define DHTTYPE DHT11 DHT dht(DHTPIN, DHTTYPE); |
These lines are for making the NodeMCU ESP8266 Board connect to the Wifi Network. Once connected, the serial monitor will display the Connection Status and prints the IP Address.
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WiFi.begin(WIFI_SSID, WIFI_PASSWORD); Serial.print("Connecting to "); Serial.print(WIFI_SSID); while (WiFi.status() != WL_CONNECTED) { Serial.print("."); delay(500); } Serial.println(); Serial.print("Connected"); Serial.print("IP Address: "); Serial.println(WiFi.localIP()); |
This statement lets the Nodemcu connect with the firebase server. If the host address and authorization key are correct then it will connect successfully
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Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH); |
Using this we are retrieving the humidity and temperature value from DHT11 Sensor.
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float h = dht.readHumidity(); float t = dht.readTemperature(); |
Then we convert the humidity and temperature Integer value to String.
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Serial.print("Humidity: "); Serial.print(h); String fireHumid = String(h) + String("%"); //Humidity integer to string conversion Serial.print("% Temperature: "); Serial.print(t); Serial.println("°C "); String fireTemp = String(t) + String("°C"); |
Now we are sending the data to google firebase using the path provided by the code.
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Firebase.pushString("/DHT11/Humidity", fireHumid); Firebase.pushString("/DHT11/Temperature", fireTemp); |
These verify whether the data is sent to the Google Firebase or not.
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if (Firebase.failed()) { Serial.print("pushing /logs failed:"); Serial.println(Firebase.error()); return; } |
Send Real-Time Sensor Data to Google Firebase with ESP8266
After uploading the code, the Nodemcu will connect to the Wifi Network. Now you can open the serial monitor, it will show the temperature and humidity reading.
When the temperature and humidity data is displayed on Serial Monitor at the same time, the data is sent to Google Firebase Database. You can just open the google Firebase console window and check the real-time entry of the data.
Now if you want to send the data from Google Firebase to Android App you can follow this tutorial:
Video Tutorial & Complete Guide
You can follow the following more tutorials about the Google Firebase:
4 Comments
Its possible connect with firebase using lan cable (W5500) ?
Is it possible in the same code to use, for example, a Display ILI9341 to show the Temperature and Humidity? How to make? Thanks
it alwasy shows push/log failed i dont know why this problem i give all info are correct
Hello I was trying the same project of blinking led using firebase
i did the firebase set up properly and copied the codes as it is but still I’m getting errors
I’m posting the errors as well below, kindly someone help
thankyou
error:-
Arduino: 1.8.19 (Windows 10), Board: “NodeMCU 1.0 (ESP-12E Module), 80 MHz, Flash, Disabled (new aborts on oom), Disabled, All SSL ciphers (most compatible), 32KB cache + 32KB IRAM (balanced), Use pgm_read macros for IRAM/PROGMEM, 4MB (FS:2MB OTA:~1019KB), 2, v2 Lower Memory, Disabled, None, Only Sketch, 115200”
C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp: In member function ‘virtual void FirebaseHttpClientEsp8266::begin(const string&)’:
C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp:47:50: error: no matching function for call to ‘begin(const char*, const char [60])’
47 | http_.begin(url.c_str(), kFirebaseFingerprint);
| ^
In file included from C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp:9:
C:\Users\ranja\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:166:10: note: candidate: ‘bool HTTPClient::begin(String, uint16_t, String)’ (near match)
166 | bool begin(String host, uint16_t port, String uri = “/”) attribute ((error(“obsolete API, use ::begin(WiFiClient, host, port, uri)”)));
| ^~~~~
C:\Users\ranja\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:166:10: note: conversion of argument 2 would be ill-formed:
C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp:47:30: error: invalid conversion from ‘const char‘ to ‘uint16_t’ {aka ‘short unsigned int’} [-fpermissive]
47 | http_.begin(url.c_str(), kFirebaseFingerprint);
| ^~~~~~~~~~~~~~~~~~~~
| |
| const char
In file included from C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp:9:
C:\Users\ranja\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:167:10: note: candidate: ‘bool HTTPClient::begin(String, const uint8_t)’ (near match)
167 | bool begin(String url, const uint8_t httpsFingerprint[20]) attribute ((error(“obsolete API, use ::begin(WiFiClientSecure, …)”)));
| ^~~~~
C:\Users\ranja\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:167:10: note: conversion of argument 2 would be ill-formed:
C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp:47:30: error: invalid conversion from ‘const char‘ to ‘const uint8_t‘ {aka ‘const unsigned char‘} [-fpermissive]
47 | http_.begin(url.c_str(), kFirebaseFingerprint);
| ^~~~~~~~~~~~~~~~~~~~
| |
| const char*
C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp: In member function ‘virtual void FirebaseHttpClientEsp8266::begin(const string&, const string&)’:
C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp:51:60: error: invalid conversion from ‘const char‘ to ‘const uint8_t‘ {aka ‘const unsigned char‘} [-fpermissive]
51 | http_.begin(host.c_str(), kFirebasePort, path.c_str(), kFirebaseFingerprint);
| ^~~~~~~~~~~~~~~~~~~~
| |
| const char
In file included from C:\Users\ranja\OneDrive\Documents\Arduino\libraries\firebase-arduino-master\src\FirebaseHttpClient_Esp8266.cpp:9:
C:\Users\ranja\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:168:70: note: initializing argument 4 of ‘bool HTTPClient::begin(String, uint16_t, String, const uint8_t*)’
168 | bool begin(String host, uint16_t port, String uri, const uint8_t httpsFingerprint[20]) attribute ((error(“obsolete API, use ::begin(WiFiClientSecure, …)”)));
| ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
exit status 1
Error compiling for board NodeMCU 1.0 (ESP-12E Module).
This report would have more information with
“Show verbose output during compilation”
option enabled in File -> Preferences.