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MANE 3351

Laboratory 7 Session

Classroom Management

Agenda

  • Topics
    • Light Detecting Resistors
    • Fritzing Diagrams
    • Circuit Diagrams
    • Analog to Digital Conversion
  • Discuss Lab 3 Assignment
  • Distribute materials needed for Lab Three

Resources

Handouts

Assignments

  • Collect materials needed for Laboratory Assignment Three
  • Complete Lab 3 before 9/25/2024 at 2:00 pm

Note: laboratory session will not meet 9/23. Dr. Timmer will be in his office during the regularly scheduled laboratory session and office hours. Please demonstrate your working system before the deadline.

Light Detecting Resistor (LDR)

  • A Light Detecting Resistor (LDR), also known as a photoresistor or photocell, is an electronic component that changes its electrical resistance based on the amount of light it is exposed to.
  • Resistance decreases as light intensity increases.
  • Resistance increases in the dark.

LDR material created by ChatGPT

Key Characteristics of LDRs

  1. Made from semiconductor materials like cadmium sulfide (CdS).
  2. Resistance decreases with increased light exposure.
  3. Has a slower response time compared to photodiodes or phototransistors.
  4. Typically used in light-sensing circuits, brightness control, and photography.

Working Principle of LDR

  • In the dark, LDR has high resistance (megaohms range).
  • When exposed to light, photons provide energy to electrons, decreasing resistance.
  • More light means more electrons are excited, resulting in lower resistance.

Common Uses of LDRs

  • Automatic street lights and night lamps.
  • Brightness control for screens and displays.
  • Light level measurement in cameras.

Limitations of LDRs

  • Sensitive to environmental conditions, such as temperature.
  • Not suitable for precise light measurements.
  • Relatively slow response time to changing light conditions.

Fritzing Diagrams

A Tool for Visualizing and Designing Electronic Circuits

Fritzing Diagram slides generated by ChatGPT

What is a Fritzing Diagram?

  • Visual representation of electronic components connected on a breadboard or circuit board.
  • Created using Fritzing, an open-source software tool for circuit design and prototyping.
  • Great for beginners and students learning electronics.

Key Features of Fritzing Diagrams

1. Breadboard View
  • Shows a graphical representation of a breadboard with components (resistors, capacitors, LEDs, microcontrollers, etc.).
  • Helps visualize physical connections using jumper wires for quick prototyping.
2. Schematic View
  • Abstract representation using component symbols (resistors, capacitors, transistors).
  • Useful for understanding circuit logic and troubleshooting.
3. PCB View (Printed Circuit Board)
  • Shows the layout of components on a custom-designed PCB.
  • Essential for moving from a breadboard prototype to a permanent solution.

Why Use Fritzing Diagrams?

  • Learning Tool: Simplifies circuit design and helps beginners understand how circuits work.
  • Easy Prototyping: Quickly create visual representations for planning and avoiding mistakes.
  • Clear Communication: Universally understood diagrams for reports, presentations, and online sharing.

Fritzing Diagram Summary

  • Fritzing diagrams help visualize and design electronic circuits.
  • Move from an idea to a physical prototype with clear, easy-to-understand diagrams.
  • Useful for learning, communicating, and building electronic projects effectively.

Fritzing Diagram for LDR

Fritzing Diagram

Circuit Diagram

  • A circuit diagram (or schematic) is a graphical representation of an electrical circuit.
  • It uses standardized symbols to show how different components are connected.
  • Essential for understanding, designing, and troubleshooting electrical and electronic systems.

Circuit Diagram slides created by ChatGPT

Key Features of Circuit Diagrams

  • Standardized Symbols:
  • Symbols represent different components: resistors, capacitors, transistors, diodes, etc.
  • Universal language for engineers worldwide.
  • Connections and Lines:
  • Lines represent electrical connections (wires).
  • Dots or nodes show where multiple connections meet.

Types of Circuit Diagrams

  1. Schematic Diagrams:
  2. Show logical connections and functionality.
  3. Focus on how components are electrically connected.
  4. Wiring Diagrams:
  5. Show the physical layout and connections of components.
  6. Used for installation and assembly.
  7. Block Diagrams:
  8. High-level overview of a system.
  9. Shows main functional units and their relationships.

Why Use Circuit Diagrams?

  • Understanding Circuit Operation:
  • Visualize how electrical components interact.
  • Design and Development:
  • Plan and create new electronic devices.
  • Troubleshooting and Repair:
  • Identify faults and issues in existing circuits.
  • Documentation and Communication:
  • Share designs and modifications clearly.

Circuit Diagram Summary

  • Circuit diagrams use symbols and lines to represent electrical circuits.
  • They are crucial for understanding, designing, analyzing, and communicating about electronic systems.
  • Learning to read and create circuit diagrams is a fundamental skill for engineering students.

Circuit Diagram for LDR

Circuit Diagram

Circuit Diagrams vs. Fritzing Diagrams

What is a Circuit Diagram?

  • A graphical representation of electrical circuits using standardized symbols.
  • Focuses on logical and functional connections between components.
  • Used for designing, analyzing, and troubleshooting circuits.

What is a Fritzing Diagram?

  • A visual representation of components connected on a breadboard or PCB.
  • Uses realistic images of components to show their physical connections.
  • Ideal for beginners, education, and rapid prototyping.

Purpose and Usage

  • Circuit Diagrams (Schematics)
  • Used to understand, design, and troubleshoot electrical circuits.
  • Focus on the logical flow and electrical functionality.
  • Fritzing Diagrams
  • Used to visualize physical connections on a breadboard or PCB.
  • Focus on practical assembly and hands-on learning.

Representation Style

  • Circuit Diagrams
  • Use standardized symbols (e.g., resistors, capacitors) to represent components.
  • Show electrical functionality and connections abstractly.
  • Fritzing Diagrams
  • Use realistic images/icons of components.
  • Represent physical layout and connections on a breadboard or PCB.

Level of Detail

  • Circuit Diagrams
  • Provide high-level abstraction, focusing on component values and electrical paths.
  • Suitable for detailed analysis and design.
  • Fritzing Diagrams
  • Provide a tangible, easy-to-understand physical view.
  • Suitable for practical assembly, prototyping, and educational purposes.

Ease of Use and Accessibility

  • Circuit Diagrams
  • Require knowledge of electrical symbols and concepts.
  • Best for professionals and advanced users.
  • Fritzing Diagrams
  • Easier for beginners; visually intuitive.
  • Ideal for learning, teaching, and hobby projects.

Software Tools

  • Circuit Diagrams
  • Created with tools like Eagle, KiCad, Altium Designer.
  • Offer advanced features for simulation and PCB design.
  • Fritzing Diagrams
  • Created using the Fritzing software.
  • Designed for rapid prototyping, education, and easy visualization.

When to Use Each Type of Diagram

  • Use Circuit Diagrams When:
  • You need to understand the electrical function and behavior.
  • Working on complex projects requiring detailed analysis.

  • Designing circuits for professional or advanced purposes.

  • Use Fritzing Diagrams When:

  • Building physical prototypes on a breadboard or PCB.
  • Teaching or learning basic electronics concepts.
  • Creating projects in a maker or hobbyist environment.

Summary

  • Circuit Diagrams: Focus on electrical functionality, design, and analysis.
  • Fritzing Diagrams: Focus on physical layout, ease of use, and rapid prototyping.
  • Both tools are essential for different stages of learning and building electronics.

Analog-to-Digital Conversion on Arduino Uno

What is Analog-to-Digital Conversion (ADC)?

  • Analog-to-Digital Conversion (ADC) is the process of converting an analog signal (continuous voltage) into a digital signal (discrete values).
  • Digital devices like the Arduino Uno need to convert real-world analog signals into a format they can process (binary values).

How Does the Arduino Uno Perform ADC?

  • The Arduino Uno uses a built-in Analog-to-Digital Converter (ADC) to read analog signals.
  • The ADC on the Arduino Uno has a 10-bit resolution, which means it converts an analog input into a digital value between 0 and 1023.
  • The ADC reads the voltage on one of its analog input pins (A0 to A5) and converts it to a digital value.

ADC Resolution and Voltage Range

  • 10-bit resolution means the input voltage is divided into 1024 levels (2^10).
  • The Arduino Uno's ADC maps input voltages from 0V (ground) to 5V (reference voltage) by default.
  • Each step in the digital output corresponds to approximately 4.9 mV (5V/1024).

How to Use ADC on Arduino Uno

  1. Connect the Analog Sensor:
  2. Connect the output of an analog sensor (e.g., potentiometer, temperature sensor) to one of the analog input pins (A0 to A5).
  3. Use analogRead() Function:
  4. The analogRead(pin) function reads the voltage on the specified analog pin.
  5. Returns a value between 0 (0V) and 1023 (5V).

Example: Reading an Analog Sensor

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 bits per second
}

void loop() {
  int sensorValue = analogRead(A0); // Read the input on analog pin A0
  Serial.println(sensorValue); // Print the value from analog pin A0 to the Serial Monitor
  delay(500); // Wait for 500 milliseconds
}