ADAS-RC: Advanced Driver-Assistance System for RC Vehicle

A compact, RTOS-inspired embedded implementation of Advanced Driver-Assistance Systems (ADAS) using an ATmega32 microcontroller as the primary ECU. The system handles throttle control, braking logic, collision avoidance, automatic headlights, pre-trip safety checks, LCD display, and Bluetooth telemetry. An ESP32 is used for TinyML lane detection and visual perception.

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Features

1. Drive Control

• ADC-based accelerator pedal input
• PWM motor control using ATmega32 timers
• Smooth acceleration with rate limiting
• Optional PI/PID motor control
• Real-time speed shown on LCD

2. Braking System

• Brake input overrides accelerator via semaphores/flags
• Smooth deceleration for realistic dynamics
• Emergency braking sequence

3. Collision Avoidance

• Ultrasonic sensor distance measurement
• Time-To-Collision (TTC) calculations
• Automatic deceleration or full braking when TTC is unsafe

4. Ambient Light & Headlight Control

• LDR/photodiode input using ADC
• Automatic headlights ON/OFF
• LCD light-status indicator

5. Pre-Trip Safety Checks

• Seat belt sensor
• Door lock sensor
• Vehicle will not move unless all checks pass

6. Bluetooth Telemetry

• BLE module for continuous reporting:

  • Speed
  • Distance
  • Brake events
  • Light status
  • Safety checks

• Real-time monitoring via laptop/mobile

7.TinyML Lane Detection (ESP32)

• ESP32 handles camera input
• Lightweight TinyML model for lane estimation
• ESP32 sends lane-adjustment hints back to ATmega32 (UART/I2C)

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System Architecture

Microcontroller Roles

Component	MCU	Role
Motor control, braking, TTC, lights, safety, LCD, telemetry	ATmega32	Main ECU
Camera processing, inference, ML lane detection	ESP32	Vision co-processor

Communication: UART between ESP32 and ATmega32.

ATmega32 Task Model (RTOS-Inspired Structure)

Although ATmega32 does not run a full RTOS, the firmware uses task scheduling patterns and prioritized execution:

"Task"	Priority	Responsibilities
Emergency/Safety	Highest	Braking override, fault flags
Motor Control	High	PWM, ramp control, PI/PID
Sensor Processing	Mid-High	Ultrasonic, LDR, encoder
Input Handling	Mid	Accelerator ADC, brake switch
LCD/UI	Mid-Low	Dashboard updates
Telemetry	Low	BLE packets
ML Input Handler	Low	Receive lane corrections from ESP32

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Core Algorithms (ATmega32)

Speed, Acceleration & Braking

• Ramp limiter for smooth throttle
• PI/PID loop for motor control
• Emergency braking cuts throttle immediately

Collision Avoidance

t_stop = v / a
d_stop = v² / (2a)
if d_obs <= d_stop + margin → emergency brake

or TTC:

TTC = d_obs / v
if TTC < t_stop + margin → brake

Sensor Filtering

• Moving average / low-pass filtering for noisy ADC
• Median-filter for ultrasonic readings

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Hardware Components

• ATmega32 microcontroller
• ESP32 for TinyML
• DC motor + driver
• Ultrasonic sensor (HC-SR04)
• Light sensor (LDR)
• LCD (16×2 or 20×4, I2C)
• BLE module
• Seatbelt & door lock sensors
• Camera for lane detection (ESP32-Cam)

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Non-Volatile Storage (ATmega32)

Stored via EEPROM/flash emulation:

• ADC calibration
• Light switching threshold
• PID gains
• Stopping margin constants
• BLE pairing/config
• Fault snapshots with CRC

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Fault Handling

• Hardware kill-switch
• Watchdog timer enabled
• Brown-out reset
• BLE loss detection
• Emergency braking override

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Testing

• Individual module tests (motor, ultrasonic, BLE)
• TTC validation at various speeds
• Safety-check tests (seatbelt/door)
• Telemetry consistency tests
• ESP32 → ATmega32 lane-data integration testing

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Example Telemetry Packet (ATmega32, BLE)

{
  "speed": 42,
  "distance": 76,
  "brake": 1,
  "lights": 0,
  "seatbelt": true,
  "door": true,
  "fault": 0
}

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How to Run

1. Flash ATmega32 firmware
2. Flash TinyML model to ESP32 (optional)
3. Power vehicle & connect BLE logger
4. Use accelerator pedal to drive
5. ATmega32 handles safety, TTC, braking, and lights
6. ESP32 performs lane detection and sends corrections

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