Build a remote control for presentations

Building a remote control for presentations can be accomplished using inexpensive hardware and basic programming. Below is a complete guide to help you create a wireless presentation remote using an Arduino board, Bluetooth module, and simple push buttons. This DIY remote will allow you to control slides (forward/backward) in tools like PowerPoint or Google Slides.

Components Needed

1. Arduino Nano or Uno

2. HC-05 Bluetooth Module (or HC-06)

3. 2x Push Buttons (for “Next” and “Previous” slide)

4. 1x 10kΩ Resistor (for each button)

5. Breadboard & jumper wires

6. Power source (battery pack or USB)

7. Computer with Bluetooth support

Wiring the Hardware

1. Bluetooth Module (HC-05) Connections:

   • VCC → 5V on Arduino

   • GND → GND

   • TX → Arduino pin 10

   • RX → Arduino pin 11 (use voltage divider to avoid over-voltage)

2. Buttons:

   • One terminal of each button → GND

   • Other terminal → Digital pin (e.g., 2 and 3) through a 10kΩ pull-up resistor to 5V

Example Layout:

• Button 1 (Next) → Pin 2

• Button 2 (Previous) → Pin 3

Arduino Code (Using SoftwareSerial)

cpp
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#include <SoftwareSerial.h>

SoftwareSerial BT(10, 11); // RX, TX

const int nextButton = 2;
const int prevButton = 3;

bool nextPressed = false;
bool prevPressed = false;

void setup() {
  pinMode(nextButton, INPUT_PULLUP);
  pinMode(prevButton, INPUT_PULLUP);
  BT.begin(9600);
}

void loop() {
  if (digitalRead(nextButton) == LOW && !nextPressed) {
    BT.println("NEXT");
    nextPressed = true;
  } else if (digitalRead(nextButton) == HIGH) {
    nextPressed = false;
  }

  if (digitalRead(prevButton) == LOW && !prevPressed) {
    BT.println("PREV");
    prevPressed = true;
  } else if (digitalRead(prevButton) == HIGH) {
    prevPressed = false;
  }
}

Computer-Side Setup

You need a small program or script running on your computer that reads incoming Bluetooth serial data and simulates key presses.

Option 1: Python Script with pyserial and pyautogui

Install the required libraries:

bash
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pip install pyserial pyautogui

Python Script:

python
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import serial
import pyautogui

# Replace 'COM5' with the port your HC-05 is connected to
bt_serial = serial.Serial('COM5', 9600)

while True:
    if bt_serial.in_waiting:
        command = bt_serial.readline().decode().strip()
        if command == "NEXT":
            pyautogui.press('right')
        elif command == "PREV":
            pyautogui.press('left')

Final Assembly and Usage

1. Upload the Arduino sketch to your board.

2. Pair the HC-05 with your computer using the default password 1234 or 0000.

3. Run the Python script on your computer.

4. Press the buttons on your DIY remote:

   • Button 1 → Next Slide

   • Button 2 → Previous Slide

Optional Enhancements

• Add more buttons for start/stop presentation (F5, Esc)

• Use a rechargeable battery and 3D printed case for portability

• Replace Bluetooth with RF (e.g., nRF24L01) or Wi-Fi (ESP32)

• Add a laser pointer module

This project is cost-effective and scalable, ideal for tech-savvy presenters or educators who want to customize their tools.