Voice Recognition Module with Arduino

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Table of Contents

Voice Recognition Module Description:

Voice Recognition Module with Arduino- This is the DFRobot’s Gravity Offline Language learning voice recognition sensor module; which is so far the best offline voice recognition module I have ever used. I am saying this after testing this remarkable piece of hardware. So, before I am going to explain anything like its features and specifications; allow me to demonstrate its functionality, and then you can decide for yourself whether it’s worth using.

I have connected the Gravity offline voice recognition module to the Arduino Nano; but instead of using the Arduino Nano, you can also use the Arduino Uno, and Arduino Mega. You can also use it with Raspberry pi and ESP32 etc; because this voice recognition module is compatible with 3.3V and 5V controller boards.

Anyway, as usual, I am using my designed Arduino LoRa development board because it already has most of the electronics components like Relays, Oled display module, a 5V buzzer, and a powerful 5V and 3A regulated power supply.

Anyways, for the demonstration purposes; I have connected a 10Kg torque Servo motor, a 110/220Vac bulb, and this board already has a 5V buzzer. So, we are going to control all these loads using built-in voice commands and using custom voice commands.

Let me also tell you, if you are planning on using similar high torque servo motors or GSM modules that draw more current then I highly recommend use an external 5V and 3A power supply, the same 5V and 3A power supply I have added on my Arduino LoRa development board; so I don’t need to use an external 5V power supply. I can use any power source between 9 and 28 volts.

By the way, it’s not compulsory to use these kinds of loads, you can start with Leds, and once you learn how to use built-in voice commands, how to record custom voice commands, and how to use them; then you can control pretty much anything. And this is what I am going to demonstrate right now. So, let’s go ahead and power up the Arduino board.

The voice recognition module has two Leds the Red(PWR) and Blue(ASR). The Red color LED is the Power indicator and the Blue color LED is the Wake-up Status Indicator. So, initially when you power up the voice recognition module, if both the LEDs are ON, you can start saying voice commands and if the Blue Color LED is OFF then it means the module is in Standby mode and during this mode it doesn’t accept any voice commands except the wake-up word; which refers to the word that switches the voice recognition module from standby mode to operational mode. It serves as the initial point of interaction between the user and voice recognition module.

I am explaining this point in detail, because in the beginning I also got confused. When I powered up the module I was repeatedly saying the wake-up word but the module wasn’t showing any response and it wasn’t switching from the Standby Mode to the Operational Mode.

I fixed this issue by not doing anything; I just waited for a while and when I heard the voice assistant saying “I am off now” then I understood the whole scene. So, each time you power up this module, you will have to wait for 20 seconds; so that the voice recognition module enters into the Standby mode and then you can wake-up the module using the built-in or custom wake-up word.

Let me practically show it to you and I am going to place the Mic next to the onboard speaker so that you can clearly hear the Voice Assistant “For the practical demonstration watch the video tutorial given at the end of this article”.

So, when you hear “I am off now”, from this point you can wake-up the module. The built-in Wake-up command is “Hello Robot”. But you can also record a custom wake-up phrase; I will demonstrate this in a minute.

Anyway, let’s first start with the built-in wake-up and voice commands. Let me tell you, there are a total of 121 built-in fixed command words.

I successfully controlled the Light bulb, Servo, and Buzzer using Built-in voice commands. When the buzzer is ON, the voice recognition module still works perfectly, so it means it can be used in noisy environments.

Now, let’s check from how far we can control the devices using voice commands. Let’s start with a distance of 6 meters and let me tell you this kind of test I have never performed on any voice recognition module.

Even from such a long distance, I successfully controlled all the loads; for me it was unbelievable and seriously I was totally amazed.

It can be used in Wheelchairs, Robots, Cars, Security Systems, Home automation projects, you can even use it to control your PC or Laptop.

Anyway, next, I am going to use custom wake-up and voice commands. You can also record custom words and phrases in other languages. You can record 17 custom commands and you can use any sound as a command. For the demonstration purposes I recorded 4 custom commands two in English language (“ Servo 90” and “Servo 0”) and two commands in Urdu or Hindi Language “light on karo” and “light off karo”. Let me demonstrate it for you.

I successfully controlled all the loads using custom voice commands. “For the practical demonstration watch the video tutorial given at the end of this article”.

How did you like this voice recognition module? Let me know in a comment and click the subscribe button if you don’t want to miss any of my upcoming videos and don’t forget to turn ON the notification bell.

Now, let’s go ahead and take a look at some of its key specifications, it’s interfacing with Arduino, how to use built-in command words, how to record custom voice commands, and how to use them in programming. So, without any further delay, let’s get started!!!

Amazon Links:

Arduino Nano USB-C Type (Recommended)

DFRobot Voice Recognition Official page

DFRobot Gravity Offline Voice Recognition Module

Servo Motor

*Disclosure: These are affiliate links. As an Amazon Associate I earn from qualifying purchases.

Voice Recognition DF2301QG V1.0:

Features:

This speech recognition sensor module is built around an offline voice recognition chip, which can be directly used without an internet connection.

It comes with 121 built-in fixed command words, eliminating the need for users to record their own voices. Here is a list of all the built-in voice commands with their desired ID’s.

Fixed Command Words	ID	Fixed Command Words	ID	Fixed Command Words	ID
Go forward	22	Retreat	23	Park a car	24
Turn left ninety degrees	25	Turn left forty-five degrees	26	Turn left thirty degrees	27
Turn right forty-five degrees	29	Turn right thirty degrees	30	Shift down a gear	31
Line tracking mode	32	Light tracking mode	33	Bluetooth mode	34
Obstacle avoidance mode	35	Face recognition	36	Object tracking	37
Object recognition	38	Line tracking	39	Color recognition	40
Tag recognition	41	Object sorting	42	Qr code recognition	43
General settings	44	Clear screen	45	Learn once	46
Forget	47	Load model	48	Save model	49
Take photos and save them	50	Save and return	51	Display number zero	52
Display number one	53	Display number two	54	Display number three	55
Display number four	56	Display number five	57	Display number six	58
Display number seven	59	Display number eight	60	Display number nine	61
Display smiley face	62	Display crying face	63	Display heart	64
Turn off dot matrix	65	Read current posture	66	Read ambient light	67
Read compass	68	Read temperature	69	Read acceleration	70
Reading sound intensity	71	Calibrate electronic gyroscope	72	Turn on the camera	73
Turn off the camera	74	Turn on the fan	75	Turn off the fan	76
Turn fan speed to gear one	77	Turn fan speed to gear two	78	Turn fan speed to gear three	79
Start oscillating	80	Stop oscillating	81	Reset	82
Set servo to ten degrees	83	Set servo to thirty degrees	84	Set servo to forty-five degrees	85
Set servo to sixty degrees	86	Set servo to ninety degrees	87	Turn on the buzzer	88
Turn off the buzzer	89	Turn on the speaker	90	Turn off the speaker	91
Play music	92	Stop playing	93	The last track	94
The next track	95	Repeat this track	96	Volume up	97
Volume down	98	Change volume to maximum	99	Change volume to minimum	100
Change volume to medium	101	Play poem	102	Turn on the light	103
Turn off the light	104	Brighten the light	105	Dim the light	106
Adjust brightness to maximum	107	Adjust brightness to minimum	108	Increase color temperature	109
Decrease color temperature	110	Adjust color temperature to maximum	111	Adjust color temperature to minimum	112
Daylight mode	113	Moonlight mode	114	Color mode	115
Set to red	116	Set to orange	117	Set to yellow	118
Set to green	119	Set to cyan	120	Set to blue	121
Set to purple	122	Set to white	123	Turn on ac	124
Turn off ac	125	Increase temperature	126	Decrease temperature	127
Cool mode	128	Heat mode	129	Auto mode	130
Dry mode	131	Fan mode	132	Enable blowing up & down	133
Disable blowing up & down	134	Enable blowing right & left	135	Disable blowing right & left	136
Open the window	137	Close the window	138	Open curtain	139
Close curtain	140	Open the door	141	Close the door	142

And supports the addition of 17 custom command words. Any sound could be trained as a command, such as whistling, snapping, or even cat meows, which brings great flexibility to interactive audio projects.

IDs from 5 to 21 are already assigned to custom commands.

Commands for learning	ID	Commands for learning	ID	Commands for learning	ID
The first custom command	5	The second custom command	6	The third custom command	7
The fourth custom command	8	The fifth custom command	9	The sixth custom command	10
The seventh custom command	11	The eighth custom command	12	The ninth custom command	13
The tenth custom command	14	The eleventh custom command	15	The twelfth custom command	16
The thirteenth custom command	17	The fourteenth custom command	18	The fifteenth custom command	19
The sixteenth custom command	20	The seventeenth custom command	21

We have a total of 9 learning-related commands which I have explained in the video.

Learning-related commands	ID	Learning-related commands	ID	Learning-related commands	ID
Learning wake word	200	Learning command word	201	Re-learn	202
Exit learning	203	I want to delete	204	Delete wake word	205
Delete command word	206	Exit deleting	207	Delete all	208

Wake-up words

Wake-up words	ID
Wake-up words for learning	1
Hello robot	2

It’s compatible with 3.3V and 5V controller boards like Arduino, Raspberry Pi, ESP32, STM32, ESP8266, and so on.

It supports both I2C and UART communication. You have a switch two select any of the two interfaces.

Since this is an offline voice recognition module, so you don’t need an internet connection which makes it more secure privacy, as users don’t have to worry about their conversation content being recorded and uploaded to the Cloud.

The module features a dual microphone design with better noise resistance and a longer recognition distance, making it relatively accurate and reliable even in noisy environments. I already demonstrated this and it was quite impressive.

It comes with a built-in speaker and an external speaker interface for real-time voice feedback of recognition results. You can use this switch to select the Onboard or external speaker. It supports an external speaker of 8 ohms and 3W passive speaker.

Specification:

Operating voltage: 3.3 – 5V

Maximum Operating Current: ≤370mA (5V)

Communication interfaces: I2C/UART

I2C Address: 0x64

Fixed Commands: 121

Fixed Wake-up Command: 1

Custom Commands: 17 and

Onboard Microphone Sensitivity: -28db

It has a total of 4 wires clearly labeled. If the switch is set to the I2C interface then the Green wire is the SDA and the Blue wire is the SCL. And if the switch is set to the UART interface then the Green wire is the Tx and the Blue wire is the Rx. If you are using a 5V compatible controller board then connect the Red wire to the 5V and GND wire to the controller GND pin. And if you are using a 3.3V compatible controller board then connect the RED and Black wires to the Controller 3.3V and GND pins.

Voice Recognition Module with Arduino:

Connect the VCC and GND wires of the voice recognition module to the Arduino 5V and GND. Since I am using the I2C interface; so that’s why I have connected the Green and Blue wires to the Arduino A4 and A5 pins.

Connect the Red and Brown wires of the Servo to the External 5V regulated power supply and connect the Yellow wire to the Arduino digital pin D2.

Out of these 4 relays I am using only 1 relay and it’s connected to the Arduino digital pin D4.

The 5V buzzer is connected to the Arduino digital pin D8.

You can follow this circuit diagram. Next, I am going to explain how to record a custom wake-up word and voice commands.

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Recording a custom voice command:

We have a total of 9 learning-related commands. Let’s say if you want to record a new wake-up word or a phrase then simply say learning wake word and then follow the voice assistant.

Watch Video Tutorial

Now, I can use the “Hi sexy” command to wake-up the module.

Now let’s record 4 custom voice commands; for this we will have to say Learning command word and then we will have to follow the voice assistant. So, let’s do it.

Watch the Video

After you have recorded the voice commands don’t forget to say Exit learning.

Exactly the same way, you can record other voice commands. Let me remind you, you can only record 17 custom voice commands.

Delete Wake Words and Command Words:

Summon the voice assistant using the awakening word (default or customized), and articulate the phrase “I want to delete” Follow the prompts to eliminate the specified command phrase as instructed.

Indication: Do you want to delete the learned wake word or command word?

Delete command word: Remove the previously acquired command phrases.

Delete wake word: Erase the learned awakening words from the system.

Delete all: Eliminate the assimilated awakening utterances and command phrases from memory.

Exit deleting.

Anyway, next, I am going to explain how to use the Built-in and custom commands in the programming to control anything we want. But, first, I am going to install the required library.

Voice Recognition Module Library:

Download: DFRobot_DF2301Q library

While the Arduino IDE is opene. Go to the Sketch Menu, then to Include Library, and click on the Add .zip Library.

Browse to the location and select the library zip folder and click on the open button.

Voice Recognition Module Arduino Programming:

#include "DFRobot_DF2301Q.h"
#include <Servo.h>
Servo servo;
#define light 4 // relay is connected to the digital pin D4
#define buzzer 8 // buzzer is connected to the digital D8
//I2C communication
DFRobot_DF2301Q_I2C asr; // activates the I2C mode of the voice recognition module
void setup() {
  Serial.begin(115200);  

  pinMode(light, OUTPUT);    //Init light pin to output mode
  pinMode(buzzer, OUTPUT);    //Init buzzer pin to output mode

  digitalWrite(light, LOW);  //Set light pin to low 
  digitalWrite(buzzer, LOW);  //Set buzzer pin to low 
   servo.attach(2); // Servo is connected to the digital pin D2

  // Init the sensor
  while (!(asr.begin())) {
    Serial.println("Communication with device failed, please check connection");
    delay(3000);
  }
  Serial.println("Begin ok!");

  /**
   * @brief Set voice volume
   * @param voc - Volume value(1~7)
   */
  asr.setVolume(7);

  /**
     @brief Set mute mode
     @param mode - Mute mode; set value 1: mute, 0: unmute
  */
  asr.setMuteMode(0);

  /**
     @brief Set wake-up duration
     @param wakeTime - Wake-up duration (0-255)
  */
  asr.setWakeTime(20);

  /**
     @brief Get wake-up duration
     @return The currently-set wake-up period
  */
  uint8_t wakeTime = 0;
  wakeTime = asr.getWakeTime();
  Serial.print("wakeTime = ");
  Serial.println(wakeTime);

   asr.playByCMDID(1);   // Wake-up command

  /**
     @brief Play the corresponding reply audio according to the ID
     @param CMDID - command word ID
  */
  //asr.playByCMDID(23);  // Command word ID
}

void loop() {
  /**
     @brief Get the ID corresponding to the command word 
     @return Return the obtained command word ID, returning 0 means no valid ID is obtained
  */
  uint8_t CMDID = asr.getCMDID();
  Serial.println(CMDID);
  switch (CMDID) {
    case 103:   //If the command is “Turn on the light”
      digitalWrite(light, HIGH);  //Turn on the light
      break;

    case 104:  //If the command is “Turn off the light”
      digitalWrite(light, LOW);  //Turn off the light
      break;

    case 141: // open the door
      servo.write(90); 
      delay(3000);
      break;

    case 142: // close the door
      
      servo.write(0);
      delay(3000);
      break;

      case 88: // turn ON the buzzer
      digitalWrite(buzzer,HIGH);
      break;

      case 89: //Turn off the buzzer"
      digitalWrite(buzzer,LOW);
      break; 


      // Custom commands in English

      case 5: // Servo 90
      servo.write(90);
      delay(3000);
      break;
      
      case 6: // Servo Zero
      servo.write(0); 
      delay(3000);
      break;



      //Custom commands in Urdu/Hindi Language

      
      case 7: // light ON karo
      digitalWrite(light, HIGH);                                 //Turn on the light
      break;

      case 8:  // light OFF karo
      digitalWrite(light, LOW);                                  
      break;


           
    default:
      if (CMDID != 0) {
        Serial.print("CMDID = ");  //Printing command ID
        Serial.println(CMDID);
      }
  }
  delay(300);
}

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#include "DFRobot_DF2301Q.h"

#include <Servo.h>

Servo servo;

#define light 4 // relay is connected to the digital pin D4

#define buzzer 8 // buzzer is connected to the digital D8

//I2C communication

DFRobot_DF2301Q_I2C asr; // activates the I2C mode of the voice recognition module

void setup() {

Serial.begin(115200);

pinMode(light, OUTPUT); //Init light pin to output mode

pinMode(buzzer, OUTPUT); //Init buzzer pin to output mode

digitalWrite(light, LOW); //Set light pin to low

digitalWrite(buzzer, LOW); //Set buzzer pin to low

servo.attach(2); // Servo is connected to the digital pin D2

// Init the sensor

while (!(asr.begin())) {

Serial.println("Communication with device failed, please check connection");

delay(3000);

}

Serial.println("Begin ok!");

/**

* @brief Set voice volume

* @param voc - Volume value(1~7)

asr.setVolume(7);

/**

@brief Set mute mode

@param mode - Mute mode; set value 1: mute, 0: unmute

asr.setMuteMode(0);

/**

@brief Set wake-up duration

@param wakeTime - Wake-up duration (0-255)

asr.setWakeTime(20);

/**

@brief Get wake-up duration

@return The currently-set wake-up period

uint8_t wakeTime = 0;

wakeTime = asr.getWakeTime();

Serial.print("wakeTime = ");

Serial.println(wakeTime);

asr.playByCMDID(1); // Wake-up command

/**

@brief Play the corresponding reply audio according to the ID

@param CMDID - command word ID

//asr.playByCMDID(23); // Command word ID

}

void loop() {

/**

@brief Get the ID corresponding to the command word

@return Return the obtained command word ID, returning 0 means no valid ID is obtained

uint8_t CMDID = asr.getCMDID();

Serial.println(CMDID);

switch (CMDID) {

case 103: //If the command is “Turn on the light”

digitalWrite(light, HIGH); //Turn on the light

break;

case 104: //If the command is “Turn off the light”

digitalWrite(light, LOW); //Turn off the light

break;

case 141: // open the door

servo.write(90);

delay(3000);

break;

case 142: // close the door

servo.write(0);

delay(3000);

break;

case 88: // turn ON the buzzer

digitalWrite(buzzer,HIGH);

break;

case 89: //Turn off the buzzer"

digitalWrite(buzzer,LOW);

break;

// Custom commands in English

case 5: // Servo 90

servo.write(90);

delay(3000);

break;

case 6: // Servo Zero

servo.write(0);

delay(3000);

break;

//Custom commands in Urdu/Hindi Language

case 7: // light ON karo

digitalWrite(light, HIGH); //Turn on the light

break;

case 8: // light OFF karo

digitalWrite(light, LOW);

break;

default:

if (CMDID != 0) {

Serial.print("CMDID = "); //Printing command ID

Serial.println(CMDID);

}

delay(300);

}

103 is the ID of “Turn ON the light”. You can confirm this from the built-in commands list. You can see 104 is the ID of “turn off the light”. So, I have used the same ID in the programming to turn off the light.

Similarly, 141 is the ID of “Open the door” and 142 is the ID of “Close the Door”.

88 and 89 are the IDs to turn ON and turn off the buzzer.

5, 6, 7, and 8 are the IDs of custom voice commands. And let me tell you, whenever you start learning command words; it will start from the first command. So, each time you add a new command, you will have to record the previous voice commands as well. So, what I suggest is that, first write all your custom voice commands on a paper and then record those in one go. This is how I did it and it worked and I have already demonstrated this. So, That’s all for you.

Watch Video Tutorial:

Engr Fahad

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One Comment

Jason Kim Davies says:

September 3, 2023 at 2:46 am

Hi

I have tried your code but am stuck – any chance you can find the time to help me please?

I am using Arduino ide v2.2.1 on a Linux system

When i run your code the serial monitor just keeps outputting the number 0 over & over on a new line

Although the DFRobot board gives an audio response to my instructions nothing lights up & nothing is printed in the serial monitor

I have tried the demo code from the DFRobot library & i get the a simiklar result in that the serial monitor does not print out anything

Any guidance you could give would be much appreciated!

Voice Recognition Module with Arduino

Voice Recognition Module Description:

Amazon Links:

Voice Recognition DF2301QG V1.0:

Features:

Specification:

Voice Recognition Module with Arduino:

Altium Designer, Altium 365, & Octopart:

Recording a custom voice command:

Voice Recognition Module Library:

Voice Recognition Module Arduino Programming:

Watch Video Tutorial:

Engr Fahad

One Comment

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Voice Recognition Module Description:

Amazon Links:

Voice Recognition DF2301QG V1.0:

Features:

Specification:

Voice Recognition Module with Arduino:

Altium Designer, Altium 365, & Octopart:

Recording a custom voice command:

Voice Recognition Module Library:

Voice Recognition Module Arduino Programming:

Watch Video Tutorial:

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