Servos
What are the wheel motors on the Bo-bot called?
Servo motors
What is the purpose of a resistor in an electrical circuit?
A resistor limits the flow of electric current in a circuit and helps control voltage and protect components.
What do we use to detect distance from our robot?
Ultrasonic distance sensor
What is the Bo-bot brain?
Arduino Uno/Parallax
Which two functions must be present in every Arduino sketch?
setup() and loop()
Precise control of movement
How does increasing the resistance value affect the current flowing through a circuit, assuming the voltage stays the same?
Increasing the resistance decreases the current, assuming the voltage stays the same (per Ohm’s law).
What is the main function of an ultrasonic distance detector?
It measures the distance to an object by emitting ultrasonic sound waves and calculating the time it takes for the echo to return.
How many digital input/output pins does the Arduino Uno R3 have?
14 digital I/O pins (6 of which can provide PWM output)
What is the purpose of the setup() function?
It runs once at startup and is used to initialize pin modes, variables, and libraries.
What are 3 of the components that make up a servo motor?
Gears, DC motor, Sensor, Electrical relay device
A resistor has color bands of brown, black, and red (with a gold tolerance band). What is its resistance value?
Brown = 1
Black = 0
Red = ×100
→ Resistance = 10 × 100 = 1000 Ω (1 kΩ) with ±5% tolerance
Why do ultrasonic sensors typically use frequencies above 20 kHz?
Because frequencies above 20 kHz are beyond human hearing, preventing audible noise while allowing accurate distance measurement.
What is the purpose of the onboard voltage regulator?
It allows the Arduino to safely accept higher input voltages (typically 7–12 V) and regulate them down to 5 V for the board.
What does pinMode(13, OUTPUT); do?
It configures digital pin 13 to act as an output pin.
What kind of applications do we use servo motors for?
Ones where we need precise control
Two resistors, 4 Ω and 6 Ω, are connected in series. What is the equivalent resistance of the combination?
10 Ω
What two main pins on a typical ultrasonic sensor (like HC-SR04) are used to measure distance, and what do they do?
TRIG pin: Sends out the ultrasonic pulse
ECHO pin: Receives the reflected pulse and outputs a signal whose duration corresponds to distance
What happens if you supply more than the recommended voltage to the Arduino Uno R3?
The board may overheat, become unstable, or suffer permanent damage to the voltage regulator or other components.
What does the following code do?
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
delay(1000);
It turns an LED connected to pin 13 ON for 1 second, OFF for 1 second, and repeats this cycle.
How does a servo motor typically receive control signals from an Arduino?
Through a Pulse Width Modulated (PWM) signal, where the pulse width determines the angle or position of the servo shaft.
A resistor is connected to a power supply and dissipates more power than its rated value. What physical effects might occur, and why can this be dangerous for the circuit?
The resistor may overheat, change value, burn, or fail completely. This is dangerous because it can damage nearby components, cause short circuits, or even start a fire.
Name two factors that can reduce the accuracy of ultrasonic distance measurements.
Temperature changes (affect speed of sound)
Soft or angled surfaces that absorb or deflect sound waves
What is the function of the USB interface chip on the Arduino Uno R3?
The USB interface chip (ATmega16U2) allows the Arduino Uno R3 to communicate with a computer over USB for uploading programs and serial communication.
Why is using delay() often discouraged in more complex Arduino programs?
Because delay() blocks the program, preventing other tasks from running simultaneously, which can cause missed inputs or slow system response.