Arduino Motors and Sensors Chapter Quiz

Module 6: Sensing and Actuation with Arduino

• 6.1 Digital and Analog Write and Read with Arduino:

  • Includes digital input to control an LED, analog output to control brightness of an LED (PWM), analog input and output to control LED brightness, and using analog input pins as digital I/O pins.
  • Uses a resistor in series with a switch for controlling an LED.
  • Arduino Uno can read input from switch (HIGH voltage when pressed, LOW when open).
  • LED brightness can be controlled with PWM (Pulse-Width Modulation).

• 6.2 DC and Servo Motors:

  • Classifies motors as DC, Hobby Servo, Standard DC Gearhead, Stepper, and AC.
  • Standard DC/Toy Motors:
    • Employ a permanent magnet and commutator.
    • Typically rated from 1.5V to 12V and 1000-20000 RPM.
    • Often inexpensive.
    • Not ideal for high torque applications
  • DC Gearhead Motors:
    • Standard DC toy motors with reduction gears.
    • Significantly lower speed but higher torque.
    • Good for Moderate torque applications.
  • Standard Hobby Servo Motors:
    • DC gearhead motors are precise positioning.
    • Limited rotation (typically 0-180 degrees).
  • Explains common hobby servo specifications.

• 6.3 DC and Servo Motor Control using Arduino:

  • Controlling DC motors:

    • Requires an H-bridge IC (e.g., L293NE or SN754410).
    • This device allows for controlling the motor's directions and speeds.

  • Controlling Finite Rotation Servo Motors:

  • Uses Arduino Servo library for easier control.

  • Controlling Continuous Rotation Servo Motors:

  • A similar method to standard servos, but continuous rotation servos have no angle limit.

  • Uses direct control of the motor speed.

• 6.4 Interfacing Sensors with Arduino:

  • Photocells and Thermistors:
  • Photocells change resistance with light intensity (lower resistance with more light).
  • Thermistors change resistance with temperature (NTC thermistors decrease resistance with increasing temperature).
  • Use a voltage divider circuit to read the sensor values.
  • Practical example code is provided to interface and use photocells/thermistors with Arduino.
  • Limit Switches:
  • Mechanical switches that change connections based on physical force.
  • Typical use cases are to detect when something has reached a limit or to halt a movement
  • Code is provided for determining the position of the switch and turning an LED on or off.
  • Ultrasonic Sensor:
  • Uses time-of-flight to measure distances from an object.
  • Has a trigger and an echo input pin.
  • Common example sensor is the HC-SR04.
  • PIR Motion Sensor:
  • Detects infrared (IR) radiation changes from moving objects.
  • Code example is provided when the sensor detects movement.
  • Infrared (IR) Line Sensors:
  • Detect lines, usually black lines.

• Potentiometer:

  • Measures rotational position (or angular position) that's linearly proportional to voltage.
  • Commonly connect to an analog input on the Arduino.

• TMP36 Sensor:

• Senses temperature, producing an analog signal directly proportional to the temperature degrees Celsius.