# Viva questions for robotics projects, with how to answer them

> Common viva questions for Arduino and ESP32 robotics projects, grouped by topic, with what a good answer must cover.

Canonical: https://roboticsengineering.in/free-library/viva-questions-for-robotics-projects/ | Published: 2026-11-03 | Updated: 2026-11-03

**Examiners ask why you chose something, not just what it is.** Prepare an answer for each question below using your own project. The notes say what a good answer covers.

## About the project

- **What problem does your project solve?** One sentence on the problem, one on your approach.
- **What is new or different compared with existing systems?** Name one existing system and the gap you cover.
- **What are the limits of your project?** Be specific: range, speed, load, lighting, battery time.

## Parts and design choices

- **Why this microcontroller?** Cover pins, speed, memory, price and what you already knew.
- **Why this motor driver and not another?** Cover current, voltage drop and heat. See [L298N vs TB6612FNG](https://roboticsengineering.in/l298n-vs-tb6612fng/).
- **How did you choose the motors and the battery?** Show the calculation. See the [battery runtime calculator](https://roboticsengineering.in/robot-battery-runtime-calculator/).
- **Why this sensor, and what is its range and error?** Quote the datasheet, then your own test.

## Electronics

- **Why do the motors and the controller share a ground?** A common reference for the signals.
- **Why is a resistor used with an LED?** To limit current. See the [LED resistor calculator](https://roboticsengineering.in/led-resistor-voltage-divider-calculator/).
- **What does PWM do?** It changes the average voltage by switching fast, which sets motor speed.
- **What happens if the supply sags?** The controller can reset. Explain how you avoided it.

## Software

- **Explain your flow chart.** Walk through one full loop.
- **How do you avoid blocking the loop?** Use millis() timing instead of long delay() calls.
- **How did you test and debug?** Serial prints, one subsystem at a time, a test table.

## Results and honesty

- **What did not work, and what did you change?** Have one real failure ready.
- **How would you improve it with more time or budget?** Name one concrete change and why.
- **What did you learn?** Name a skill, not a feeling.

## Related

[Report template](https://roboticsengineering.in/free-library/robotics-project-report-template/), [Free final-year project pack](https://roboticsengineering.in/free-project-pack/), [Error library](https://roboticsengineering.in/fix/).

Last reviewed: November 2026. Free to copy and adapt for your own project and college work. Keep your own measurements and results; do not copy figures from this page into a report as if you measured them.