DIYables Web Apps Web Rotator

WebRotator Example - Setup Instructions

Overview

The WebRotator example creates an interactive rotatable disc control interface accessible from any web browser. Designed for Arduino Uno R4 WiFi and DIYables STEM V4 IoT educational platform with enhanced motor control capabilities, built-in servo/stepper control features, and seamless integration with robotics educational modules. Perfect for controlling servo motors, stepper motors, robotic arms, antennas, or any system requiring precise rotational control.

Arduino WebRotator Example - Interactive Rotational Control Tutorial

Features

  • Interactive Rotatable Disc: Touch and mouse-controlled disc interface
  • Dual Operation Modes: Continuous (0-360°) and Limited angle range
  • Real-time Angle Feedback: Precise angle display and control
  • Visual Position Indicator: Clear disc position marker with gradient design
  • Touch & Mouse Support: Works on desktop, tablet, and mobile devices
  • Automatic Config Handling: Set mode and range once in constructor
  • WebSocket Communication: Instant response without page refresh
  • Professional UI: Conic gradient design with smooth rotation
  • Platform Extensible: Currently implemented for Arduino Uno R4 WiFi, but can be extended for other hardware platforms. See DIYables_WebApps_ESP32

Hardware Preparation

1×Arduino UNO R4 WiFi
1×Alternatively, DIYables STEM V4 IoT
1×USB Cable Type-A to Type-C (for USB-A PC)
1×USB Cable Type-C to Type-C (for USB-C PC)
1×Servo Motor (optional for testing)
1×Breadboard
1×Jumper Wires
1×Recommended: Screw Terminal Block Shield for Arduino UNO R4
1×Recommended: Breadboard Shield for Arduino UNO R4
1×Recommended: Enclosure for Arduino UNO R4
1×Recommended: Power Splitter for Arduino UNO R4
1×Recommended: Prototyping Base Plate & Breadboard Kit for Arduino UNO

Or you can buy the following kits:

1×DIYables STEM V4 IoT Starter Kit (Arduino included)
1×DIYables Sensor Kit (30 sensors/displays)
1×DIYables Sensor Kit (18 sensors/displays)
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Additionally, some of these links are for products from our own brand, DIYables .

Setup Instructions

Detailed Instructions

Follow these instructions step by step:

  • If this is your first time using the Arduino Uno R4 WiFi/DIYables STEM V4 IoT, refer to the tutorial on setting up the environment for Arduino Uno R4 WiFi/DIYables STEM V4 IoT in the Arduino IDE.
  • Connect the Arduino Uno R4/DIYables STEM V4 IoT board to your computer using a USB cable.
  • Launch the Arduino IDE on your computer.
  • Select the appropriate Arduino Uno R4 board (e.g., Arduino Uno R4 WiFi) and COM port.
  • Navigate to the Libraries icon on the left bar of the Arduino IDE.
  • Search "DIYables WebApps", then find the DIYables WebApps library by DIYables
  • Click Install button to install the library.
Arduino UNO R4 DIYables WebApps library
  • You will be asked for installing some other library dependencies
  • Click Install All button to install all library dependencies.
Arduino UNO R4 DIYables WebApps dependency
  • On Arduino IDE, Go to File Examples DIYables WebApps WebRotator example, or copy the above code and paste it to the editor of Arduino IDE
/* * DIYables WebApp Library - Web Rotator Example * * This example demonstrates the Web Rotator application: * - Interactive rotatable disc control * - Two modes: Continuous rotation and Limited angle range * - Real-time angle feedback with WebSocket communication * - Touch and mouse support for desktop and mobile * * Features: * - Configurable rotation modes (continuous or limited) * - Beautiful conic gradient disc with visual indicator * - Real-time angle display and feedback * - WebSocket communication for live updates * - Professional responsive UI design * * Hardware: Arduino Uno R4 WiFi or DIYables STEM V4 IoT * * Setup: * 1. Update WiFi credentials below * 2. Upload the sketch to your Arduino * 3. Open Serial Monitor to see the IP address * 4. Navigate to http://[arduino-ip]/web-rotator in your web browser */ #include <DIYablesWebApps.h> // WiFi credentials - UPDATE THESE WITH YOUR NETWORK const char WIFI_SSID[] = "YOUR_WIFI_SSID"; const char WIFI_PASSWORD[] = "YOUR_WIFI_PASSWORD"; // Create WebApp server and page instances UnoR4ServerFactory serverFactory; DIYablesWebAppServer webAppsServer(serverFactory, 80, 81); DIYablesHomePage homePage; // Rotator configuration constants const int ROTATOR_MODE = ROTATOR_MODE_CONTINUOUS; // Change to ROTATOR_MODE_LIMITED for limited rotation const float MIN_ANGLE = 0.0; // Minimum angle for limited mode const float MAX_ANGLE = 180.0; // Maximum angle for limited mode // Create WebRotator page with configuration //DIYablesWebRotatorPage webRotatorPage(ROTATOR_MODE_CONTINUOUS); DIYablesWebRotatorPage webRotatorPage(ROTATOR_MODE_LIMITED, MIN_ANGLE, MAX_ANGLE); // Variables for angle tracking float currentAngle = 0.0; void setup() { Serial.begin(9600); delay(1000); // TODO: Initialize your hardware pins here Serial.println("DIYables WebApp - Web Rotator Example"); // Add pages to server webAppsServer.addApp(&homePage); webAppsServer.addApp(&webRotatorPage); // Set 404 Not Found page (optional - for better user experience) webAppsServer.setNotFoundPage(DIYablesNotFoundPage()); // Set callback functions for WebRotator webRotatorPage.onRotatorAngleFromWeb(onRotatorAngleReceived); // Start server webAppsServer.begin(WIFI_SSID, WIFI_PASSWORD); if (ROTATOR_MODE == ROTATOR_MODE_LIMITED) { Serial.println("\nRotator Mode: Limited"); Serial.print("Angle Range: "); Serial.print(MIN_ANGLE); Serial.print("° to "); Serial.print(MAX_ANGLE); Serial.println("°"); } else { Serial.println("\nRotator Mode: Continuous Rotation"); } Serial.println("\nTurn the disc in your web browser to control the rotator!"); } void loop() { // Handle web server and WebSocket connections webAppsServer.loop(); // Simulate rotator movement or control actual hardware here // For demonstration, we'll just echo back the received angle delay(10); } /** * Callback function called when angle is received from web interface * This is where you would control your actual rotator hardware */ void onRotatorAngleReceived(float angle) { currentAngle = angle; Serial.print("Rotator angle received: "); Serial.print(angle, 1); Serial.println("°"); // TODO: Add your rotator control code here // Examples: // - Control servo motor: servo.write(map(angle, 0, 360, 0, 180)); // - Control stepper motor: stepper.moveTo(angle * stepsPerDegree); // - Control DC motor with encoder feedback // - Send commands to external rotator controller // Note: No echo back to avoid interfering with smooth web interface rotation } /** * Example function to change rotator mode at runtime * Call this function to switch between continuous and limited modes */ void setRotatorMode(int mode, float minAng = 0, float maxAng = 360) { webRotatorPage.setRotatorMode(mode, minAng, maxAng); Serial.print("Rotator mode changed to: "); if (mode == ROTATOR_MODE_LIMITED) { Serial.print("Limited ("); Serial.print(minAng); Serial.print("° to "); Serial.print(maxAng); Serial.println("°)"); } else { Serial.println("Continuous"); } } /** * Example function to send angle updates to web interface * Call this function when your rotator position changes */ void sendAngleUpdate(float angle) { currentAngle = angle; webRotatorPage.sendToWebRotator(angle); Serial.print("Angle update sent to web: "); Serial.print(angle, 1); Serial.println("°"); }
  • Configure WiFi credentials in the code by updating these lines:
const char WIFI_SSID[] = "YOUR_WIFI_NETWORK"; const char WIFI_PASSWORD[] = "YOUR_WIFI_PASSWORD";
  • Click Upload button on Arduino IDE to upload code to Arduino UNO R4/DIYables STEM V4 IoT
  • Open the Serial Monitor
  • Check out the result on Serial Monitor. It looks like the below
COM6
Send
DIYables WebApp - Web Rotator Example INFO: Added app / INFO: Added app /web-rotator DIYables WebApp Library Platform: Arduino Uno R4 WiFi Network connected! IP address: 192.168.0.2 HTTP server started on port 80 Configuring WebSocket server callbacks... WebSocket server started on port 81 WebSocket URL: ws://192.168.0.2:81 WebSocket server started on port 81 ========================================== DIYables WebApp Ready! ========================================== 📱 Web Interface: http://192.168.0.2 🔗 WebSocket: ws://192.168.0.2:81 📋 Available Applications: 🏠 Home Page: http://192.168.0.2/ 🔄 Web Rotator: http://192.168.0.2/web-rotator ==========================================
Autoscroll Show timestamp
Clear output
9600 baud  
Newline  
  • If you do not see anything, reboot Arduino board.
  • Open a web browser on your PC or mobile phone.
  • Type the IP address shown in the Serial Monitor to the web browser
  • Example: http://192.168.1.100
  • You will see the home page like below image:
Arduino UNO R4 DIYables WebApp Home page with Web Rotator app
  • Click to the Web Rotator link, you will see the Web Rotator app's UI like the below:
Arduino UNO R4 DIYables WebApp Web Rotator app
  • Or you can also access the page directly by IP address followed by /web-rotator. For example: http://192.168.1.100/web-rotator
  • You will see an interactive rotatable disc that you can drag to control rotation

Web Interface Features

Rotatable Disc Control

  • Interactive Disc: Click and drag to rotate the disc
  • Visual Feedback: Real-time angle display and position indicator
  • Smooth Animation: Fluid rotation with professional gradient design
  • Angle Display: Current angle shown in degrees
  • Mode Indicator: Shows current rotation mode and limits

Touch and Mouse Support

  • Desktop Control: Mouse click and drag
  • Mobile Control: Touch and swipe gestures
  • Responsive Design: Optimized for all screen sizes
  • Visual Cues: Clear indicators for interaction areas

Code Configuration

Rotator Setup

// Continuous rotation mode (full 0-360 degrees) DIYablesWebRotatorPage webRotatorPage(ROTATOR_MODE_CONTINUOUS); // Limited rotation mode with custom range DIYablesWebRotatorPage webRotatorPage(ROTATOR_MODE_LIMITED, 0.0, 180.0); // Set up angle callback webRotatorPage.onRotatorAngleFromWeb(onRotatorAngleReceived);

Receiving Angle Commands

void onRotatorAngleReceived(float angle) { Serial.print("Rotator angle received: "); Serial.print(angle, 1); Serial.println("°"); // Control your hardware here }

Operation Modes

Continuous Mode

  • Full Rotation: 0° to 360° and beyond, with no upper limit
  • No Wrap Around: Angle values can increase above 360° and do not reset to 0°
  • Use Cases: Continuous rotation servos, antennas, turntables
  • Configuration: ROTATOR_MODE_CONTINUOUS

Limited Mode

  • Custom Range: Define minimum and maximum angles
  • Boundary Limits: Prevents rotation beyond set limits
  • Use Cases: Standard servos, robotic arms, steering systems
  • Configuration: ROTATOR_MODE_LIMITED, minAngle, maxAngle

Hardware Integration

Servo Motor Control

Note: The following code snippet is a partial example and must be integrated into your main Arduino sketch to function correctly.

#include <Servo.h> Servo myServo; // Set rotator to limited mode: 0 to 180 degrees DIYablesWebRotatorPage webRotatorPage(ROTATOR_MODE_LIMITED, 0.0, 180.0); void setup() { myServo.attach(9); // Servo on pin 9 webRotatorPage.onRotatorAngleFromWeb(onRotatorAngleReceived); } void onRotatorAngleReceived(float angle) { // Directly write angle (0-180) to servo myServo.write((int)angle); }

Stepper Motor Control

#include <Stepper.h> const int stepsPerRevolution = 200; Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11); void onRotatorAngleReceived(float angle) { // Calculate steps for desired angle int steps = (angle / 360.0) * stepsPerRevolution; myStepper.step(steps); }

Customization Options

Angle Range

  • Minimum Angle: Set lowest allowed rotation
  • Maximum Angle: Set highest allowed rotation
  • Default Position: Starting angle when system boots
  • Resolution: Control precision of angle updates

Visual Appearance

The web interface automatically adapts to your configuration:

  • Range Display: Shows configured angle limits
  • Mode Indicator: Displays current operation mode
  • Position Marker: Visual indicator of current angle
  • Gradient Design: Professional appearance with smooth colors

Common Use Cases

Educational Projects

  • Servo Control Learning: Understanding PWM and servo operation
  • Robotics Education: Arm positioning, joint control
  • Antenna Positioning: Directional antenna control
  • Camera Pan/Tilt: Remote camera positioning

Practical Applications

  • Home Automation: Automated blinds, vents, doors
  • Robotics: Robotic arm joints, mobile robot steering
  • IoT Projects: Remote positioning systems
  • Industrial: Automated positioning, valve control

Troubleshooting

Rotation Not Working

  • Check WiFi connection and WebSocket status
  • Verify callback function is properly set
  • Ensure servo/motor is properly connected
  • Check power supply for motors

Incorrect Angle Values

  • Verify angle mapping for your specific hardware
  • Check servo library and pin configuration
  • Ensure proper scaling in callback function
  • Test with Serial Monitor output

Connection Issues

  • Verify IP address in browser
  • Check firewall settings
  • Ensure 2.4GHz WiFi network (5GHz not supported)
  • Try refreshing browser page

Advanced Features

Runtime Mode Changes

You can change rotator mode during operation:

void setRotatorMode(int mode, float minAng = 0, float maxAng = 360) { webRotatorPage.setRotatorMode(mode, minAng, maxAng); Serial.print("Rotator mode changed to: "); if (mode == ROTATOR_MODE_LIMITED) { Serial.print("Limited ("); Serial.print(minAng); Serial.print("° to "); Serial.print(maxAng); Serial.println("°)"); } else { Serial.println("Continuous"); } }

Position Feedback

Send current position back to the web interface:

void sendAngleUpdate(float angle) { currentAngle = angle; webRotatorPage.sendToWebRotator(angle); Serial.print("Angle update sent to web: "); Serial.print(angle, 1); Serial.println("°"); }

Note: Sending frequent angle feedback to the web interface may cause less smooth movement. Use this feature only if real-time position updates are required.

Multi-Axis Control

Combine multiple rotators for complex positioning:

DIYablesWebRotatorPage panRotator(ROTATOR_MODE_CONTINUOUS); DIYablesWebRotatorPage tiltRotator(ROTATOR_MODE_LIMITED, -90.0, 90.0); server.addApp(&panRotator); server.addApp(&tiltRotator);

Educational Integration

STEM Learning Objectives

  • Motor Control: Understanding servo and stepper operation
  • Coordinate Systems: Angle measurement and positioning
  • Web Technologies: Real-time control interfaces
  • Programming: Callback functions, hardware control

Classroom Activities

  • Servo Calibration: Learn servo operation and PWM signals
  • Position Control: Practice precise positioning tasks
  • System Integration: Combine sensors with motor control
  • Problem Solving: Debug hardware and software issues

This example provides a comprehensive foundation for rotational control systems, perfect for both educational and practical robotics applications.

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