Voice-Assisted Mini Companion Bot

Inspired by the Disney Research team's bipedal animatronic characters that interact with crowds in real-time. I wanted to create a similar but smaller, desktop friendly design but smaller design for my desktop. Open-source leg mechanism designs (Legolas and Tinker) make this project a good choice for a final project. Unlike existing options like EMO, which are expensive to import in India, this design is more affordable

The inspiration behind the idea made by Disney

Table of Conents

The Idea
CAD Design
PCB Schematic
Voice Input
OLED Output
Servo Output
References

1. The Idea

Brainstorming

Many ideas were discussed including a mini companion bot and a robotic humanoid chatbot among others (see more in Week 1), but ultimately I choose the All-Seeing Eye as my final project for the following reasons:

Sketching

Key Features

The Companion Bot has the following key features:

An LCD display on the robot's front shows three expressions—happy, sad, and neutral—with accompanying sound effects from a speaker.
The robot responds to voice commands for power control and can display time, weather, and temperature information, replacing its standard expressions.
The robot features bird-like legs that fold when powered down to save space. When activated, the legs extend to full height, enhancing its interactive presence.
Front-mounted sensors help the robot detect and avoid obstacles while preventing falls from the desktop.

2. CAD Design

This is model when rendered as a still image.

This is the model when rendered as a turntable.

Project FlowChart

3. Possible PCB Schematic

Trying to create a PCB for my final project using the ESP32-WROOM-32E module

Here I have made a schematic for a PCB for my final project. The design has to be refined in the coming weeks, but theoretically, there is a voltage regulator circuit making sure that the MCU receives only 3.3V. Also I can communicate with my MCU using a USB A to C type connector. I will continue to refine this design as the weeks progress.

For more information, see Week 6 documentation.

4. Voice Input

In week 9, I made an an audio input sensor, which could potentially be able to recognize certain voice commands

If the sound input is loud enough to cross a threshhold, the LED lights up

To see more, check out my documentation for Week 9. In the future, I would like to make it possible for the device to recognize voice commands

5. OLED Output

In Output Devices Week I learnt to make a simple facial animation on the OLED display. To achive this, I used this tutorial that uses the U8g2 library, which is supported by Wokwi simulator. Following the tutorial I went to Lopaka.app, selected the U8g2 library, and created a new project


                    
    #include <U8g2lib.h>
    #include <Wire.h>
    
    long dt;
    long vert;
    
    U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE);
    
    void setup(){
        Serial.begin(115200);
        if (!u8g2.begin()){
        Serial.println("Display not initialized");
        for(;;);
        }
        delay(1000);
        Serial.println("Display initialized");
    }
    
    void mouth_open(){
        u8g2.clearBuffer();
        u8g2.setFontMode(1);
        u8g2.setBitmapMode(1);
        u8g2.drawFilledEllipse(83, 33+vert, 8, 13);
        u8g2.drawFilledEllipse(62, 54+vert, 8, 6);
        u8g2.drawFilledEllipse(41, 33+vert, 8, 13);
        u8g2.sendBuffer();
    }
    
    void mouth_half_open (){
        u8g2.clearBuffer();
        u8g2.setFontMode(1);
        u8g2.setBitmapMode(1);
        u8g2.drawFilledEllipse(83, 33+vert, 8, 13);
        u8g2.drawFilledEllipse(41, 33+vert, 8, 13);
        u8g2.drawFilledEllipse(62, 57+vert, 8, 3);
        u8g2.sendBuffer();
    } 
    
    void mouth_closed (){
        u8g2.clearBuffer();
        u8g2.setFontMode(1);
        u8g2.setBitmapMode(1);
        u8g2.drawFilledEllipse(83, 33+vert, 8, 13);
        u8g2.drawFilledEllipse(62, 59+vert, 8, 1);
        u8g2.drawFilledEllipse(41, 33+vert, 8, 13);
        u8g2.sendBuffer();
    }
    
    void loop(){
        vert = random(0,3);
        dt = random(0,150);
        
        mouth_closed();
        delay(dt);
        // Serial.println(dt);
    
        vert = random(0,3);
        dt = random(0,200);
        mouth_half_open();
        delay(dt);
        // Serial.println(dt);
    
        vert = random(0,3);
        dt = random(0,200);
        mouth_open();
        delay(dt);
        // Serial.println(dt);
    
        vert = random(0,3);
        dt = random(0,200);
        mouth_half_open();
        delay(dt);
        // Serial.println(dt);
    
        vert = random(0,3);
        dt = random(0,200);
        mouth_closed();
        delay(dt);
        // Serial.println(dt);
    }