An ESP32-powered robotic radar system that performs real-time environmental scanning, object detection, and live radar visualization through a web dashboard.
This project implements a radar-style robotic scanning system using an ultrasonic sensor mounted on a servo motor.
The system continuously scans the environment from 0° to 180°, detects nearby objects, and provides multi-layer feedback through LEDs, buzzer alerts, and a live radar dashboard.
When an object enters the detection range, the robot validates the signal and locks onto the target, similar to real radar tracking systems.
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https://www.youtube.com/watch?v=6M3X1xsha7I
https://www.youtube.com/watch?v=Nw1-PEBm7XM&feature=youtu.be
https://scaniverse.com/scan/qmovmeqbyeedrgni
- ESP32 microcontroller
- HC-SR04 ultrasonic sensor
- Micro servo motor
- LED proximity ladder
- Piezo buzzer
- Analog joystick
- Push button
- C++
- Arduino Framework
- PWM Servo Control
- State Machine Control
- Non-blocking timing (
millis())
- ESP32 WiFi SoftAP
- Embedded HTTP Server
- JSON telemetry API
- HTML
- CSS
- JavaScript
- Canvas API
Input Layer
- Ultrasonic Sensor → Distance measurement
- Joystick → Manual control
- Button → Mode switching
Processing Layer
- ESP32
- Signal validation
- Control logic
- Servo control
- LED mapping
- Buzzer control
Output Layer
- Servo scanning
- LED proximity display
- Buzzer alerts
- Radar web dashboard
- 0°–180° radar sweep
- Autonomous scanning mode
- Manual joystick control
- Object locking mechanism
- Distance-based LED ladder
- Parking-sensor style buzzer alerts
- Real-time radar dashboard
- Live telemetry streaming
The robot operates using a layered decision architecture that processes sensor signals, validates detections, and controls actuation in real time.
The system follows a state-based control flow:
SCAN → DETECT → LOCK → RELEASE
SCAN
The servo continuously sweeps the ultrasonic sensor from 0°–180°.
DETECT
Distance measurements are validated to filter noise and false echoes.
LOCK
If an object remains within the detection threshold for a specified time window, the system locks onto the target and freezes the servo.
RELEASE
If the object moves outside the release threshold, scanning resumes.
The ESP32 hosts a web interface that visualizes the radar sweep in real time.
Features include:
- animated radar sweep
- echo persistence visualization
- lock indication
- distance telemetry
- synchronized LED ladder
| Component | ESP32 Pin | Description |
|---|---|---|
| HC-SR04 Trigger | GPIO 5 | Sends ultrasonic pulse |
| HC-SR04 Echo | GPIO 18 | Receives reflected signal |
| Servo Motor Signal | GPIO 13 | Controls radar sweep motion |
| Buzzer | GPIO 4 | Audio proximity alert |
| LED 1 | GPIO 16 | Proximity indicator |
| LED 2 | GPIO 17 | Proximity indicator |
| LED 3 | GPIO 19 | Proximity indicator |
| LED 4 | GPIO 21 | Proximity indicator |
| LED 5 | GPIO 22 | Proximity indicator |
| LED 6 | GPIO 23 | Proximity indicator |
| LED 7 | GPIO 25 | Proximity indicator |
| Joystick X-Axis | GPIO 34 | Manual servo angle control |
| Joystick Button | GPIO 14 | Mode toggle (AUTO / MANUAL) |
| Device | Connection |
|---|---|
| HC-SR04 VCC | 5V |
| HC-SR04 GND | GND |
| Servo VCC | 5V |
| Servo GND | GND |
| LEDs | Through resistors to GPIO pins |
| Buzzer | GPIO → Buzzer → GND |
| Joystick VCC | 3.3V |
| Joystick GND | GND |
Connect the components to the ESP32 as shown in the circuit diagram:
- HC-SR04 ultrasonic sensor
- Micro servo motor
- LED proximity ladder
- Piezo buzzer
- Analog joystick
- Push button
Refer to the wiring diagram:
Download and install the Arduino IDE:
https://www.arduino.cc/en/software
- Open Arduino IDE
- Go to File → Preferences
- Add the following URL to Additional Board Manager URLs:
https://dl.espressif.com/dl/package_esp32_index.json
- Go to Tools → Board → Board Manager
- Install ESP32 by Espressif Systems
-
Open the firmware file: https://github.com/adithya-a-labs/esp32-robot-radar-system/blob/main/firmware/robot_radar_firmware.ino
-
Select the correct board: ESP32 Dev Module
-
Connect the ESP32 via USB
-
Click Upload
- Power the ESP32
- Connect to the WiFi network created by the ESP32
- Open a browser and navigate to the dashboard IP
The radar interface will display the live scanning system.
- LiDAR-based sensing
- ROS integration
- SLAM-based mapping
- autonomous navigation
- machine learning object detection
A detailed explanation of the system architecture, control logic, and implementation methodology is available in the full project report:
Developed as part of the Robotics Interest Group induction project.
Adithya A
Electronics & Communication Engineering
NIT Calicut
India
MIT License