Smart Glove Car

A gesture-controlled car built with an ESP32-C3 microcontroller and MPU6050 IMU. Hand tilt movements are captured in real-time, processed on the glove-side ESP32-C3, and transmitted wirelessly as directional commands to a receiver unit mounted on the car.

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Contributors

• I built the smart glove unit, including sensor integration, gesture detection, wireless transmission, and glove-side programming.
• My teammate Rithobratho Saha built the car unit, including motor driver integration, receiver-side control logic, and vehicle assembly.

Table of Contents

• System Architecture
• Hardware Components
• Circuit Connections
• Gesture-to-Command Mapping
• Software Stack
• Project Structure
• Setup & Flashing
• How It Works
• Future Improvements

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System Architecture

┌─────────────────────────────┐          Wireless (ESP-NOW / Wi-Fi)          ┌──────────────────────────────┐
│        GLOVE UNIT           │ ─────────────────────────────────────────────▶│         CAR UNIT             │
│                             │                                               │                              │
│  MPU6050 (Accelerometer +   │                                               │  ESP32-C3 (Receiver)         │
│  Gyroscope)                 │                                               │  L298N / L293D Motor Driver  │
│       │                     │                                               │  DC Motors (x4 or x2)        │
│       ▼                     │                                               │  LiPo / 18650 Battery Pack   │
│  ESP32-C3 (Transmitter)     │                                               │                              │
│  USB-C / LiPo powered       │                                               │                              │
└─────────────────────────────┘                                               └──────────────────────────────┘

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Hardware Components

Glove Unit (Transmitter)

Component	Specification	Purpose
ESP32-C3	160 MHz RISC-V, Wi-Fi/BLE	Main MCU + wireless transmitter
MPU6050	6-axis IMU (3-axis accel + 3-axis gyro), I2C	Motion / tilt sensing
LiPo Battery	3.7V 500–1000 mAh	Portable power for glove
3.3V LDO Regulator	AMS1117 or similar	Regulate battery voltage to 3.3V

Circuit Connections

Glove Side — MPU6050 → ESP32-C3

MPU6050 Pin	ESP32-C3 Pin	Description
VCC	3.3V	Power
GND	GND	Ground
SDA	GPIO6	I2C Data
SCL	GPIO7	I2C Clock
AD0	GND	I2C address = 0x68
INT	GPIO4 (optional)	Data-ready interrupt

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Gesture-to-Command Mapping

The MPU6050 outputs raw pitch and roll values which are thresholded into discrete commands.

Gesture	Pitch / Roll Threshold	Car Action
Tilt Forward	Pitch < -20°	Move Forward
Tilt Backward	Pitch > +20°	Move Backward
Tilt Left	Roll < -20°	Turn Left
Tilt Right	Roll > +20°	Turn Right
Level / Flat	−20° ≤ P,R ≤ +20°	Stop

Thresholds can be tuned in src/main.cpp via the PITCH_THRESHOLD and ROLL_THRESHOLD defines.

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Software Stack

• Framework: Arduino (via PlatformIO)
• Platform: Espressif ESP32-C3
• Key Libraries:
  • Wire.h — I2C communication with MPU6050
  • MPU6050.h / Adafruit MPU6050 — IMU driver & DMP
  • esp_now.h — Low-latency peer-to-peer ESP-NOW protocol
  • WiFi.h — Required for ESP-NOW channel initialization

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Project Structure

smart-glove-car/
├── src/
│   └── main.cpp           # Main application logic (transmitter or receiver)
├── include/
│   └── config.h           # Pin definitions, thresholds, MAC addresses
├── lib/                   # Local/vendored libraries (if any)
├── test/                  # Unit tests
├── platformio.ini         # PlatformIO build configuration
└── .vscode/               # Editor settings

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Setup & Flashing

Prerequisites

1. Install PlatformIO (VS Code extension or CLI).
2. Clone this repository:

   git clone https://github.com/Divija2612/smart-glove-car.git
   cd smart-glove-car

Step 1 — Get Receiver MAC Address

Before flashing the transmitter, you need the car-side ESP32-C3's MAC address.

Flash a simple MAC-printer sketch to the receiver ESP32-C3:

#include <WiFi.h>
void setup() {
  Serial.begin(115200);
  WiFi.mode(WIFI_STA);
  Serial.println(WiFi.macAddress());
}
void loop() {}

Note the printed MAC (e.g., AA:BB:CC:DD:EE:FF).

Step 2 — Configure MAC Address

In include/config.h, set:

uint8_t receiverMAC[] = {0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF};

Step 3 — Flash Receiver (Car Unit)

# Set the build environment to 'receiver' in platformio.ini, then:
pio run -e receiver -t upload

Step 4 — Flash Transmitter (Glove Unit)

pio run -e transmitter -t upload

Step 5 — Monitor Serial Output

pio device monitor --baud 115200

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How It Works

1. Sensor Acquisition: The MPU6050 samples accelerometer and gyroscope data at ~100 Hz over I2C.
2. Angle Computation: Raw accelerometer values are converted to pitch and roll angles using atan2(). A complementary filter (or the MPU6050 DMP) fuses gyroscope data to reduce noise.
3. Command Encoding: Angles are compared against thresholds to produce a Command enum value (FORWARD, BACKWARD, LEFT, RIGHT, STOP).
4. Wireless Transmission: The command is packed into a small struct and sent via ESP-NOW to the receiver's MAC address. Latency is typically under 5 ms.
5. Motor Control: The receiver decodes the command and drives the L298N IN1–IN4 pins accordingly. PWM on ENA/ENB controls speed.

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Key Challenges & Fixes

1. Serial Monitor Connection Issue The program contained an unintended infinite while loop, which prevented the serial monitor from establishing a connection. I carefully reviewed the entire codebase, identified the loop causing the blockage, and corrected it to restore proper communication.
2. Power Consumption During Wi-Fi Communication Transmitting data over Wi-Fi required significantly higher power than expected. As a result, the system could not be reliably powered by a standard battery setup. To ensure stable performance, a power bank was used as an external power source.
3. Incorrect GPIO Pin Configuration Initially, the motor driver connections were made to GPIO pins 4 and 5, which led to incorrect behavior (continuous backward motion). After reconfiguring the connections to GPIO pins 8 and 9, the system responded correctly, enabling proper control commands such as forward, backward, left, right, and stop.