Shematic

Component placement and routing were done in KiCad. Design Rule Check passed successfully.

Pcb Board

• In KiCad PCB Editor, go to File → Plot, set format to SVG, and select necessary layers (e.g., F.Cu, Edge.Cuts).
• Click Plot to export SVG files for each selected layer.
• Open SVGs in Inkscape to edit, align, or combine layers as needed.

• Import the edited SVG into MOD to generate toolpaths.
• Export G-code from the MOD tool for CNC milling, g.

To use MODs with the Wegstr PCB milling machine, export your board’s traces and outlines from KiCad as SVG files. Open MODs (mod.cba.mit.edu), load the appropriate PCB module (e.g., Roland mill outline or traces), and import the SVG. Set the tool diameter, cut depth, and offsets based on your bit size. Generate the toolpath and save the .nc G-code file. Then, open the Wegstr web interface or controller software, upload the G-code, and start the milling job. Ensure the board is properly fixed, and the tool zeroed on the copper surface for accurate PCB milling results.

The Wegstr PCB milling machine is a compact, desktop CNC tool designed for rapid prototyping of printed circuit boards. It enables users to mill single- or double- sided PCBs by carving copper-clad boards using precise toolpaths. Ideal for makers, educators, and electronics engineers, it supports various input formats like G -code and integrates with software like MODs and FlatCAM. With a user-friendly interface and high-precision spindle, Wegstr allows fast, chemical-free PCB fabrication. Its portability and ease of use make it suitable for labs or small workshops, offering an efficient alternative to traditional etching methods for creating custom electronics prototypes.

After the PCB is finely milled using the Wegstr machine, it must be carefully cleaned to ensure proper electrical performance and solderability. Begin by brushing off loose copper dust and debris using a soft anti-static brush. Next, use isopropyl alcohol (IPA) and a lint-free cloth or cotton swab to wipe the board surface, removing any residual particles or oil. Pay special attention to the milled tracks and pads. Cleaning not only improves the appearance of the board but also prevents shorts and improves solder adhesion during assembly. Ensure the board is completely dry before proceeding with component mounting or testing.

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Once the PCB is cleaned and dry, female pin headers (female adaptors) are carefully soldered onto the designated tracks or pads. Align each header pin precisely with its corresponding hole or pad to ensure proper electrical contact. Use a fine-tipped soldering iron and appropriate solder wire to create clean, shiny joints without bridging adjacent pins. Proper soldering ensures reliable mechanical and electrical connections for plugging in modules or components. After soldering, inspect all joints for cold solder or shorts, and rework if necessary. This step completes the board’s assembly, making it ready for testing and integration into electronic projects.

Arduino Code – Project Two: Digital Inputs

// Project Two - Digital Inputs

void setup()
{
    pinMode(10, OUTPUT);   // D10 LED OUT
    pinMode(2, OUTPUT);    // D0 Switch Input Identify LED
    pinMode(3, OUTPUT);    // D1 Motor One Lead
    pinMode(4, OUTPUT);    // D2 Motor another Lead

    pinMode(9, INPUT);     // D9 LDR Sensor Input
    pinMode(5, INPUT);     // D3 Switch 1 (Limit Switch 1)
    pinMode(6, INPUT);     // D4 Switch 2 (Limit Switch 2)
}

void loop()
{
    if (digitalRead(9) == HIGH)
    {
        digitalWrite(10, HIGH);  // LED ON when LDR detects light

        if (digitalRead(5) == LOW)
        {
            digitalWrite(2, HIGH);  // Identify LED ON
            digitalWrite(3, HIGH);  // Motor Forward
            digitalWrite(4, LOW);
        }
        else
        {
            digitalWrite(2, LOW); 
            digitalWrite(3, LOW);
            digitalWrite(4, LOW);
        }

        if (digitalRead(6) == LOW)
        {
            digitalWrite(2, HIGH);  // Identify LED ON
            digitalWrite(3, LOW);   // Motor Reverse
            digitalWrite(4, HIGH);   
        }
        else
        {
            digitalWrite(2, LOW); 
            digitalWrite(3, LOW);
            digitalWrite(4, LOW);
        }
    }

    if (digitalRead(9) == LOW)
    {
        digitalWrite(10, LOW);     // Turn off LED
        digitalWrite(2, HIGH);     // Blink Identify LED
        delay(1000);
        digitalWrite(2, LOW);  
        delay(1000);
    }
}
  

Problem I Encountered During Output Device Assignment

The ESP32-C3 operates at 3.3V logic and cannot directly drive high-current devices like a 12V motor. Initially, attempting to control the motor directly caused voltage instability and risked damaging the microcontroller.

Solution:

I used a relay module to safely switch the 12V motor ON and OFF. The relay’s input was triggered by the ESP32 GPIO, and it isolated the high-voltage motor circuit from the low-voltage logic. This approach allowed me to control the motor safely using digital HIGH/LOW signals.

Working Process

When an obstacle or darkness is detected by the LDR (Light Dependent Resistor) module, it changes its resistance, which is read as a signal by the microcontroller. This input is processed by the Seeed Studio ESP32-C3 board programmed using the Arduino IDE. Upon detection, the microcontroller activates a 12V LED as a visual indicator and powers the DC motor. The motor’s operation is controlled through two limit switches, which define its travel limits, ensuring it moves only within a safe range. This mechanism demonstrates a simple yet effective light-triggered automation system.

As soon as the light level returns to normal and is detected by the LDR, the system immediately stops both the motor and the LED, halting all movement and conserving energy. This quick response ensures the motor only operates during specific conditions (i.e., darkness or blockage), making the setup ideal for light-sensitive automation projects such as smart barriers, object detection systems, or interactive displays. The entire process runs on the ESP32-C3 board, which provides Wi-Fi/BLE capabilities, offering potential for further IoT-based enhancements.