🧪 Testing and Feature Options

🎯 Lesson Objective

In this lesson, students will learn:

• How to test the Single Limit Switch Bumper Robot
• How to verify that the limit switch is working correctly
• How to check motor movement and robot direction
• How to troubleshoot common problems
• Additional features that can improve the robot

This lesson focuses on testing the robot and improving its functionality.

1️⃣ Checking the Hardware Setup

Before running the robot, verify that all components are connected properly.

Check the following:

✔ ESP32 is powered correctly
✔ Limit switch is connected to the correct GPIO pin
✔ Motor driver connections are correct
✔ Motors are connected to the correct output terminals
✔ Battery polarity is correct
✔ All components share a common ground

Incorrect wiring is the most common reason why robotics projects fail.

Always verify the circuit before powering the robot.

2️⃣ Uploading the Program

To begin testing the robot:

1️⃣ Connect the ESP32 to the computer using a USB cable.
2️⃣ Open Arduino IDE.
3️⃣ Select the correct ESP32 board.
4️⃣ Select the correct COM port.
5️⃣ Upload the program.

Once the program is uploaded successfully, the robot will begin operating.

3️⃣ Testing the Limit Switch

The first step is to verify that the limit switch is working correctly.

Steps to test:

1️⃣ Open the Serial Monitor in Arduino IDE.
2️⃣ Set the baud rate to 9600.
3️⃣ Press the limit switch manually.

Example output:

Explanation:

• 1 → switch not pressed
• 0 → switch pressed

If the values change when the switch is pressed, the switch is functioning properly.

4️⃣ Testing the Robot Movement

After confirming that the switch works, test the robot movement.

Steps:

1️⃣ Place the robot on a flat surface.
2️⃣ Turn on the robot power supply.
3️⃣ The robot should start moving forward.
4️⃣ Press the limit switch manually.

Expected behavior:

➡ Robot moves backward.
➡ Robot turns right.
➡ Robot continues moving forward.

If the robot performs these actions correctly, the system is functioning properly.

5️⃣ Complete Robot Test

Now test the robot in a real environment.

Testing process:

1️⃣ Place the robot on the floor.
2️⃣ Allow the robot to move forward.
3️⃣ Let the robot hit an obstacle.
4️⃣ The limit switch will be pressed.
5️⃣ The robot will move backward and turn.

This confirms that the Single Limit Switch Bumper Robot is working correctly.

6️⃣ Troubleshooting Common Problems

Students may encounter some common issues while testing.

Problem: Robot not moving

Possible causes:

• Battery not connected
• Motor driver wiring incorrect
• Motors not connected properly

Solution:

Check motor driver connections and battery power.

Problem: Limit switch not detected

Possible causes:

• Switch wired incorrectly
• Wrong GPIO pin used
• Switch damaged

Solution:

Verify switch wiring and check the pin number in the program.

Problem: Robot moving continuously backward

Possible cause:

The limit switch is always pressed or stuck.

Solution:

Check the switch position and confirm that it moves freely.

7️⃣ Improving the Robot

Once the robot works successfully, several improvements can be added.

Possible improvements include:

💡 Adding LED indicators when the switch is pressed
🔊 Adding a buzzer sound when the robot hits an obstacle
⚡ Adding PWM motor speed control
🤖 Adding two more limit switches for better obstacle detection

These upgrades make the robot more intelligent and interactive.

8️⃣ Real-World Applications

Contact detection systems like this are used in many real-world machines.

Examples include:

🤖 Robot vacuum cleaners
🏭 Industrial safety systems
🚪 Elevator door safety sensors
📦 Automated warehouse robots

These systems help machines detect obstacles and avoid damage.

🚀 What Happens Next

Now that you have successfully built and tested the Single Limit Switch Bumper Robot, the next project will introduce distance-based obstacle detection.