Input Devices

Hero Shot

Task: Input Devices

Group assignment:

  • Probe an input device(s)'s analog levels and digital signals
  • Document your work on the group work page and reflect on your individual page what you learned

    • Individual project:

  • Measure something: add a sensor to a microcontroller board that you have designed and read it.

    • Learning Experience

    I gained practical experience in sensor integration, PCB design, and microcontroller programming during this assignment. I investigated a variety of temperature and LDR sensors, comprehending their operation and how they work with microcontrollers such as the XIAO ESP32-C3. I also designed a custom PCB in KiCad, incorporating an inventive octopus-shaped layout, and successfully milled the board using SRM-20. I built a functional circuit through soldering and component placement, and used Arduino IDE to program it, implementing sensor-based LED control. Debugging challenges, like I2C device detection issues, helped me improve my problem-solving abilities. This experience improved my comprehension of analog and digital signals, circuit design, and practical applications of sensors, preparing me for more complex electronics projects.

    Key Accomplishments

    ✅Successfully combined and tested the XIAO ESP32-C3 with LDR sensors.
    ✅Created a unique PCB in KiCad with an inventive octopus-shaped architecture and sensor connections.
    ✅Created Gerber files, transformed them into G-code, then used SRM-20 to mill PCBs.
    ✅Finished component placement and soldering, guaranteeing a completely working circuit.
    ✅To process sensor data and control an LED based on light intensity, I wrote and uploaded Arduino ID code.
    ✅I2C device detection problems were debugged and fixed, enhancing circuit troubleshooting abilities.
    ✅Used the Serial Monitor in Arduino IDE for real-time data monitoring and validation.
    ✅Recognized the distinctions between digital and analog signals and how they are used in sensor-based systems.
    ✅successfully recorded every step of the process, including debugging, programming, manufacture, and design.
    Individual Assignment:

    For my Individual Assignment, I have decided to test various temperature sensors and LDR sensors using the serial monitor of the Arduino IDE. Along with this, I thought of integrating the sensor into my board so that it can also function as an input device.

    What is a sensor

    An apparatus that senses physical events and transforms them into electrical impulses to generate a digital output is called a sensor. Various environmental stimuli, such as heat, light, sound, pressure, magnetism, or motion, can be captured and analyzed by sensors of different types. The results are then transmitted through a readable display.

    Sensor Photo


    In Phone we have many types of sensor



    LDR Sensor

    LDRs are tiny light-sensing devices also known as photoresistors. An LDR is a resistor whose resistance changes as the amount of light falling on it changes. The resistance of the LDR decreases with an increase in light intensity. This property allows us to use them for making light-sensing circuits.


    Analog Signal

    An analog signal is a signal that represents ALL of the possible values in a given range as it varies with respect to time; it is analogous to the time-varying quantity it represents.



    Digital Signal

    On the contrary, a digital signal is a signal that represents a quantity as a series of discontinuous values. spribe aviator game! The digital signal can represent only 2 values: ‘HIGH‘ and ‘LOW‘.




    Reference Website
    PCB design

    For the input device, I planned to create a PCB with a complete circuit for the LDR (light-dependent resistor) sensor. I would solder the LDR inside the circuit and also add a temperature sensor. My goal is to analyze how both digital and analog signals travel through the circuit. To make the PCB design unique, I decided to shape it like an octopus.

    Check out my previous assignment for designing PCB

    "I learned something new in circuit design: with the help of a photo, some changes can be made to the PCB design in a different way."



    I downloaded a photo of an octopus design using a search engine.



    First, I opened KiCad and clicked on the image converter."



    Then, I went to the file menu and uploaded my photo. According to the PCB, I set the output size between 100 to 129 mm.



    Then exported the symbol file and mod file to the KiCad folder.



    I went to Preferences and added my symbol library in the Symbol Library section.



    Then, I went to Manage Footprint Library and added the mod file that I had exported.



    I have added all the components to my schematic design according to the project requirements.



    I went inside Place Footprint, then click on Choose Footprint, and a symbol appeared. After the symbol appeared, I entered the name of my component. and i add my component.



    I selected and drew a line around all four sides of the octopus to create an edge cut. After the edge cut was done, I deleted the previous file.



    complete the routing of my components.



    Then, I viewed the 3D model of my design and downloaded the file.


    Gerber file to PNG file process.


    Then, I visited the Garbar2IMG website at home, uploaded both my Garbar file, and downloaded the PNG file.

    If you want to know the process, please check my Electronic Production assignment.

    G code generation mods


    With the help of Mods, I generated both the interior and exterior designs.

    If you want to know the process, please check my Electronic Production assignment.

    PCB Cutting Process

    Then, I applied double tape to the PCB according to my dimensions, properly set it on the machine bed, and executed my design command.


    Then, I properly placed the PCB on the bed of the SRM-20.


    I fixed the end mill bit.


    I sent the G-code file command to the machine.


    PCB cutting is complete


    The PCB was removed and cleaned.

    If you want to know the process, please check my Electronic Production assignment.

    Soldering Process

    Components I used for the PCB:

  • XIAO ESP32-C3 - 1 piece
  • 4-Pin Connector - 2 pieces
  • 3-Pin Connector - 1 piece
  • LEDs - 8 pieces
  • Resistor 4.99KΩ (4990Ω) - 8 piece
  • Resistor 0KΩ - 2 piece
  • LDR (Light Dependent Resistor) - 1 piece


    • I started a soldering.


    First of soldered IC.


    Then I solder a LED, a resistor, a three pin connector and a 4P corrector.


    Then, I checked the connectivity of the entire charge controller and tested the LED to verify if my board was working.


    After this, I also soldered all the LEDs and resistors.

    My micro controller board is ready for programming and testing

    Programming and testing process


    First of all, I opened Arduino IDE and uploaded the code.

    Code 

    #define LDR_PIN A0   // LDR connected to A0 (Analog)
#define LED_PIN 8    // LED connected to D8

void setup() {
    pinMode(LED_PIN, OUTPUT);
    Serial.begin(115200);
}

void loop() {
    int ldrValue = analogRead(LDR_PIN);
    Serial.print("LDR Value: ");
    Serial.println(ldrValue);

    if (ldrValue < 1500) {
        digitalWrite(LED_PIN, HIGH);
        Serial.println("Dark Detected - LED ON");
    } else {
        digitalWrite(LED_PIN, LOW);
        Serial.println("Light Detected - LED OFF");
    }

    delay(500);
}

    Reference website - Chatgpt


    Then, I checked on the serial monitor whether my LDR is working for the sensor and LED or not. And it was working


    LED blinking with LDR sensor: When we turn on the light, the LED turns off, and when we turn off the light, the LED turns on. All of this was detected by the LDR sensor as per the programming we had done.

    Tools I Used
    KiCad Origin File
  • PCB FILE