Mentor Mitra AI is an interactive educational toy designed to assist and engage children through voice-based interaction, emotional response, and adaptive learning. Built on a custom-designed PCB using ATmega328P, and integrated with the AI Thinker VC02 module, this toy can detect environmental inputs, interact with children using speech, and share progress data to a custom React + Node.js web dashboard for parents or teachers to monitor learning milestones.

This project blends embedded system design, AI communication, and educational psychology to offer a meaningful learning companion for kids — while promoting STEM concepts to students and hobbyists.

⚙️ How does it work?🔧 1. Hardware System

• Microcontroller: ATmega328P (on a custom PCB)

• Modules Used:

  • AI Thinker VC02 for voice-to-AI processing

  • 1.3” OLED Display for feedback display

  • Touch & Sound Sensors for user input

  • RGB LED and Servo Motor for expressive response

  • Temperature Sensor (e.g., DHT11 or LM35)

• Power Regulation: 5V regulated using MP3608 step-down or USB

🧠 2. AI Communication

• VC02 sends user voice input to a hosted AI model (e.g., via Gemini API)

• AI generates intelligent text output based on context

• ESP32 parses the AI output and sends commands to ATmega328P for action (e.g., move servo, show emotion on LED, say something)

🌐 3. Web Dashboard

• Built using React.js (Frontend) and Node.js (Backend)

• Displays:

  • Child interaction history

  • Emotions detected

  • Learning progress

• Data sent from ESP32 to server via Wi-Fi and displayed live

🔨 Step-by-Step Tutorials to Build Mentor Mitra AI

Step 1: PCB Design (EasyEDA)

• Design schematic using ATmega328P, headers for VC02, OLED, sensors, and power regulation

• Generate and order PCB & assemble components

  
• 

• Step 2: Module Wiring

  • Connect VC02 via UART

  • I2C for OLED + sensors

  • PWM for servo + digital pins for touch/sound

    
  • 

• Step 3: Integrate AI Thinker VC02

• Using The SDK Builder made the custom SDK and Firmware file for the Voice thinker , used the link given in the software part to make your's . 

• Step 4: Web Dashboard Setup

  • Build React frontend with charts and logs

  • Setup Node.js backend with REST API

  • Connect ESP32 via POST requests to the backend

    Step 5: Final Assembly

    • 3D-print or build casing

    • Combine electronics and mount inside

      
    • 

    • Step 6: Testing and Calibration

      • Test all inputs, refine voice output timing, LED reaction, and data accuracy

      • Testing and Calibration Refer this Video https://drive.google.com/file/d/1AEFEz5XWi5ajWzWyZAeG_wYVmIOZi15E/view?usp=drive_link

      • Step 7: Also made a Custom Chat bot on Poe -

        • Refer here - https://poe.com/mentor_mitra_ai

           

          Step 8: Programming ATmega328P

          • Write firmware using Arduino IDE or PlatformIO

          • Control servo, display text, LEDs, and process input

            #include <DS18B20_INT.h>

            
            

            #include <DS18B20_INT.h>

            
            

            #include <DS18B20_INT.h>

            
            

            #include <Servo.h>

            
            
            

            Servo servo1;

            Servo servo2;

            
            
            

            const int redPin = 6;

            const int greenPin = 7;

            const int bluePin = 8;

            
            

            const int soundPin = 12;

            
            

            void setup() {

             

              servo1.attach(9);

              servo2.attach(10);

            
            
            

              randomSeed(analogRead(A0));

            
            

             

              pinMode(redPin, OUTPUT);

              pinMode(greenPin, OUTPUT);

              pinMode(bluePin, OUTPUT);

            
            

              pinMode(soundPin, INPUT);

            }

            
            

            void loop() {

              // Read sound sensor

              int soundDetected = digitalRead(soundPin);

            
            

             

              if (soundDetected == LOW) {

                Serial.println("Sound Detected");

               

                unsigned long startTime = millis();

                while (millis() - startTime < 2000) {

                  // Generate random angles for the servos

                  int angle1 = random(0, 181);

                  int angle2 = random(0, 181);

            
            

                  // Move each servo to a random angle

                  servo1.write(angle1);

                  servo2.write(angle2);

            
            

                 

                  int color = random(0, 3);

                  switch (color) {

                    case 0:  // Red

                      digitalWrite(redPin, HIGH);

                      digitalWrite(greenPin, LOW);

                      digitalWrite(bluePin, LOW);

                      break;

                    case 1:  // Green

                      digitalWrite(redPin, LOW);

                      digitalWrite(greenPin, HIGH);

                      digitalWrite(bluePin, LOW);

                      break;

                    case 2:  // Blue

                      digitalWrite(redPin, LOW);

                      digitalWrite(greenPin, LOW);

                      digitalWrite(bluePin, HIGH);

                      break;

                  }

                  delay(500);

              } else {

            
            

                digitalWrite(redPin, LOW);

                digitalWrite(greenPin, LOW);

                digitalWrite(bluePin, LOW);

              }

            }
            #include <OneWire.h>

            
            

            #include <DallasTemperature.h>

            #include <DHT.h>

            #include <SPI.h>

            #include <Wire.h>

            #include <Adafruit_GFX.h>

            #include <Adafruit_SH110X.h>

            
            
            

            #define i2c_Address 0x3c

            unsigned int receivedValue = 0;

            #define SCREEN_WIDTH 128 // OLED display width, in pixels

            #define SCREEN_HEIGHT 64 // OLED dispay height, in pixels

            #define OLED_RESET -1  

            Adafruit_SH1106G display = Adafruit_SH1106G(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

             

            #include <FluxGarage_RoboEyes.h>

            roboEyes roboEyes; // create RoboEyes instance

            
            

            void setup()   {

              Serial.begin(9600);

             

              delay(250); // wait for the OLED to power up

              display.begin(i2c_Address, true); // Address 0x3C default

            
            
            

              // Startup robo eyes

              roboEyes.begin(SCREEN_WIDTH, SCREEN_HEIGHT, 100); // screen-width, screen-height, max framerate

            
            

              // Define some automated eyes behaviour

              roboEyes.setAutoblinker(ON, 3, 2);

              pinMode(9, INPUT);

              pinMode(10, INPUT);

              pinMode(11, INPUT);

              pinMode(12, INPUT);

              pinMode(8, INPUT);//sound sensor

             

            } // end of setup

            
            
            

            void loop() {

             roboEyes.update();

             roboEyes.setMood(DEFAULT);

             roboEyes.setCuriosity(OFF);

             roboEyes.setAutoblinker(ON);

             roboEyes.setWidth(36, 36);

             roboEyes.setHeight(36, 36);

             roboEyes.setBorderradius(8, 8);

             roboEyes.setSpacebetween(10);

             

              if (digitalRead(8) == LOW) {

                int starTime = 0;

                while (starTime < 50) {

                roboEyes.setWidth(20, 20);

                roboEyes.setHeight(36, 36);

                roboEyes.setBorderradius(8, 8);

                roboEyes.setSpacebetween(20);

                starTime++;

                roboEyes.update();

                Serial.println("Sound Detected!");

            
            

              }

             

              }

             

              if (digitalRead(9) == HIGH) {

                Serial.println("Sensor on pin 8 touched");

                roboEyes.setMood(TIRED);

              }

              if (digitalRead(10) == HIGH) {

                Serial.println("Sensor on pin 9 touched");

                roboEyes.setMood(HAPPY);

              }

              if (digitalRead(11) == HIGH) {

                Serial.println("Sensor on pin 10 touched");

                roboEyes.setMood(ANGRY);

              }

              if (digitalRead(12) == HIGH) {

                Serial.println("Sensor on pin 11 touched");

             

                roboEyes.anim_laugh();

               

            
            

              }

            
            

            }

            
            
            

           

        🎯 Why this project matters

        This project makes AI approachable, embedded design exciting, and education fun. With open documentation, low-cost components, and step-by-step guidance, it encourages:

        • Kids to learn with joy

        • Students to build real-world systems

        • Educators to adopt AI-driven feedback

        It’s not just a toy—it’s a platform to introduce AI, electronics, and empathy into learning.

        ---

        🙌 What others can learn from your experience

        • How to prototype complex systems step by step

        • Building and flashing a custom PCB with microcontrollers

        • Integrating cloud AI in embedded systems (ESP32 + VC02)

        • Designing dashboards with real-time data updates

        • Creating impactful educational technology from scratch