Line Following & Maze Solving Robot

This project implements an autonomous line-following and maze-solving robot built on the ESP-IDF framework using ESP-IDF.
The robot is capable of:

• Following a black line using a PID-based control system
• Detecting and navigating junctions (left, right, T, and U-turns)
• Detecting objects using an IR sensor and pushing them forward
• Detecting the end of the maze and stopping precisely
• Real-time PID tuning through an integrated HTTP tuning server

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🧠 Project Overview

The robot uses a 5-channel line sensor array to read surface reflectance values. These readings are normalized, processed, and used to calculate an error signal which drives a PID controller.
The PID output adjusts motor speeds dynamically to keep the bot centered on the line.

In addition to line following, the bot intelligently handles:

• T-junctions, left turns, right turns, and U-turns
• End detection to stop at maze completion
• Box detection using an IR proximity sensor (GPIO input)
• Automatic push mechanism when a box is detected on its path

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🧮 Control Logic

1. Line Sensor Normalization

Sensor values are mapped between LSA_MIN and LSA_MAX and inverted for consistent logic.

2. PID Control

The robot computes:

• error — deviation from the center of the line
• correction — proportional + integral + derivative adjustments

Motor speeds are tuned as:

left_duty = OPT_DUTY + correction
right_duty = OPT_DUTY - correction

3. Object Detection & Push Logic

When IR sensor (GPIO 0) detects an object:

• Robot moves forward briefly to push the box
• Reverses and realigns itself on the track

4. End Detection

After executing a left turn, the robot verifies if it has reached the end of the path using line sensor conditions and timing.

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🧰 Build & Flash Instructions

1. Clone the repository:

   git clone https://github.com/varun05050505/Maze-solving-bot.git
   

2. Set up the ESP-IDF environment:

   . $HOME/esp/esp-idf/export.sh
   

3. Flash the code

   idf.py build
   idf.py -p /dev/ttyUSB0 flash monitor