Input Devices Week

1. Introduction

During the Input Devices week, I focused on understanding how sensors interact with a microcontroller and how real-world data can be measured and processed.

The main objective of this assignment was to measure something using a sensor connected to my custom PCB. I used the board that I designed and fabricated in a previous assignment, which allowed me to integrate new components and build a complete system.

This week helped me understand the full workflow of sensing: from physical input to digital processing.

2. Group Assignment

For the group assignment, we explored how input devices produce both analog and digital signals.

We used tools such as: - Multimeter to measure voltage levels
- Oscilloscope to observe signal behavior over time

By probing signals, we analyzed how they change and how sensors communicate with microcontrollers.

🔗 Link to group assignment page

What I Learned

From this activity, I learned: - The difference between analog and digital signals
- How voltage represents data
- How to use a multimeter and oscilloscope
- How physical changes affect electrical signals

3. Programming the Board

I programmed my custom PCB using the Arduino IDE. I connected the board to my computer, selected the correct port, and uploaded the code.

This step confirmed that: - My board is working correctly
- The microcontroller can execute code
- Communication is successful

Here I will show photos of the uploading process.

Before working with sensors, I tested my board using the Blink example.

This test verified: - Power supply
- Microcontroller functionality
- Correct output pin behavior

The LED blinking confirmed everything is working correctly.

Here I will show a video of the blinking LED.

5. Mini Project – Ultrasonic Sensor

For my individual assignment, I created a system to measure distance using an ultrasonic sensor.

Components Used:

  • Buzzer (output)
  • Ultrasonic sensor (input)
  • Custom PCB

The goal was to measure distance and respond with sound.

6. Circuit Connection and Design

I connected the ultrasonic sensor and buzzer to my board:

  • Ultrasonic sensor:
  • VCC → Power
  • GND → Ground
  • TRIG → Digital pin

  • ECHO → Digital pin

  • Buzzer:

  • Connected to a digital output pin

This setup allows the board to send a signal and receive the reflected echo to calculate distance.

Here I will show the connections.

7. Code Explanation

The program works as follows: 1. Sends a pulse from the TRIG pin
2. Measures the time for the echo to return
3. Calculates the distance
4. Activates the buzzer if an object is close

This allows the system to detect distance in real time.

Here I will show the code.

8. Final Result

The final system works successfully: - The ultrasonic sensor measures distance
- The microcontroller processes the signal
- The buzzer reacts when an object is near

This demonstrates a complete input → process → output system.

Here I will show the final working result.

9. Problems and Solutions

During the process, I encountered some issues:

  • Board not detected → fixed by installing drivers
  • Upload errors → fixed by checking port and wiring
  • Incorrect distance readings → fixed by adjusting code and connections

These challenges helped me improve my debugging skills.

10. Design Files and Documentation

  • Custom PCB was designed in a previous assignment
  • Source code is included
  • Design files are attached or linked

📁 Include original files here

11. Hero Shot

Final result of my board and project:

📸 Hero shot of my PCB

12. Conclusion

This week helped me understand how input devices work with microcontrollers.

I learned: - How ultrasonic sensors measure distance
- How to process real-world data
- How to build a responsive system

This knowledge is essential for future projects in robotics and smart systems.