8. Electronics
Production

Group assignment

During this week I concluded that the mini mill does not like me. Even though this assignment involved many failed attempts, it helped me understand the complete workflow of electronics production: from exporting the PCB correctly to milling, soldering, and finally programming a functional custom board.

Here is a full guide on how to make your own physical PCB.

Tasks:

★

Make and test a microcontroller development board that you designed.


Meme

Toolpath Preparation

Preparing Digital Files

The first part of this week was preparing the digital files so the milling machine could understand my PCB. This meant exporting the board correctly from KiCad and then transforming those files into an RML toolpath using Mods.

STEPS FOR THE TOOLPATH:


Final Result:

Milling Process

Working with the Mini Mill

Once the digital files were ready, it was time to move to the mini mill. This was the most challenging part of the week because even a very small calibration mistake could ruin the entire PCB.

STEPS TO MILL THE PCB:

Soldering and Assembly

Assembling the Components

After finally getting a clean PCB, the next step was assembling all the electronic components by soldering them carefully into place.

STEPS TO SOLDER:

Programming

Testing the Electronics

Once the board was assembled, the last technical step was programming it to verify that the electronics were actually working.

The first step was to connect the PCB to Arduino IDE, then I wrote some code to test the PCB, in which I turned the LEDs on and off with the button. This entire process is shown in the following carousel, and the code that can be copied is below the carousel.



#include <Adafruit_NeoPixel.h>                        // NeoPixel library
 
#define PIN_LEDS  D6                                   // LEDs on pin D6
#define PIN_BOTON D7                                   // Button on pin D7
#define NUM_LEDS  3                                    // Number of LEDs
 
Adafruit_NeoPixel strip(NUM_LEDS, PIN_LEDS, NEO_GRB + NEO_KHZ800);
 
void setup() {
  Serial.begin(115200);                                // Start serial monitor
  pinMode(PIN_BOTON, INPUT_PULLUP);                    // Button reads HIGH normally, LOW when pressed
  strip.begin();                                       // Start LEDs
  strip.setBrightness(30);                             // Set brightness (0-255)
}
 
void loop() {
  if (digitalRead(PIN_BOTON) == LOW) {                 // Button pressed
    Serial.println("Button pressed - LEDs ON");
    strip.setPixelColor(0, strip.Color(255, 20,   147));  // LED 1 - Red
    strip.setPixelColor(1, strip.Color(0,   255, 255));  // LED 2 - Green
    strip.setPixelColor(2, strip.Color(128,   0, 128));  // LED 3 - Blue
    strip.show();                                      // Send colors to LEDs
  } else {                                             // Button released
    Serial.println("Button released - LEDs OFF");
    strip.clear();                                     // Turn off all LEDs
    strip.show();
  }
 
  delay(100);                                          // Wait 100ms
}

Final Result

After several failed exports, calibration problems, and three milling attempts, I finally obtained a fully working custom development board.


Final Reflection

The PCB works as a custom programmable Arduino-like board that connects through USB and can be programmed normally. Seeing the Neopixels finally turn on after so many fabrication issues made the whole process worth it.

MISTAKES DURING THIS WEEK:

  • My first Gerber export was wrong.
  • The Gerber converter merged traces and cuts incorrectly.
  • Calibration on the mini mill required multiple trial-and-error attempts.
  • The first milled traces looked rough.
  • I had to fabricate three PCBs before getting the final working one.

Fails:


Final Result:

Final PCB