Week 15. System Integration

My MAKERGATE Project - The Big Picture

So MAKERGATE is basically my attempt to solve a real problem in our maker space - expensive tools going missing or getting damaged because anyone can just walk up and use them. My solution? Make them smart and secure! Here's how all the pieces work together:

ESP32s Board

This is the brain of everything - controls all the other components

RFID Reader

Reads user cards to identify who wants to use the equipment

Nokia LCD Screen

Shows status messages and user prompts

4x5 Keypad

For entering PIN codes (because cards alone aren't secure enough)

My Custom PCB

Brings everything together on one board I designed myself

Making the PCB Real (SRM 20 Milling and Soldering)

Time to turn my digital design into an actual circuit board! Here's how I did it with our SRM 20:

First, I Uploadedthe svg into Mods CE to create the actual toolpath. This step is crucial - the milling machine needs precise instructions on where to cut.

After generating the G-code, I set up the copper board in the SRM20 and started the milling process. Here's the machine doing its thing:

The milled PCB turned out pretty clean! No broken traces or missing pads.

Then came the tedious part - soldering all the components one by one. Started with the smallest components and worked my way up to the bigger ones.

Finally got everything soldered on and connected. It actually looks like a real product!

Testing the Whole System

Time for the moment of truth - does everything actually work together? I started with some basic code to test the core functionality.

Here's the test code I wrote to see if the relay would respond to authentication:

My MAKERGATE Code - How I Made It Work

Writing the code for this was actually pretty fun once I figured out how to get all the components talking to each other. Here's how I built the security logic:

The Libraries I Needed

#include <SPI.h>
#include <MFRC522.h>
#include <Keypad.h>
#include <Adafruit_GFX.h>
#include <Adafruit_PCD8544.h>

These are basically the instruction manuals that tell my ESP32 how to talk to each component. Without these, nothing would work!

Wiring Everything Up in Code

// ESP32 pin connections
#define SS_PIN    21   // RFID reader
#define RST_PIN   22   // RFID reset
#define SCK_PIN   18   // SPI clock
#define MOSI_PIN  23   // SPI data out
#define MISO_PIN  19   // SPI data in
#define OUTPUT_PIN 26  // The important one - controls equipment power!

// Nokia display connections
#define LCD_CLK    14 
#define LCD_DIN   25  
#define LCD_DC    12  
#define LCD_CE    33  
#define LCD_RST   32

Pin 26 is the star of the show - that's what actually turns equipment on and off. Everything else is just input and feedback.

Setting Up the Keypad

char keys[ROWS][COLS] = {
  {'1', '2', '3'},
  {'4', '5', '6'},
  {'7', '8', '9'},
  {'*', '0', '#'}
};

I mapped out the keypad so users can press '#' to submit their password and '*' to clear what they've typed. Pretty standard stuff.

System Startup

void setup() {
  Serial.begin(115200);
  pinMode(OUTPUT_PIN, OUTPUT);
  digitalWrite(OUTPUT_PIN, LOW); // Start with equipment OFF
  
  // Get all components talking
  SPI.begin(SCK_PIN, MISO_PIN, MOSI_PIN, SS_PIN);
  mfrc522.PCD_Init();
  display.begin();
  
  // Welcome screen
  display.println("RFID Security");
  display.println("System Ready");
  display.println("Place card");
  display.println("near reader");
}

The most important line here is setting OUTPUT_PIN to LOW - this ensures equipment starts OFF and stays that way until someone proves they belong!

The Security Logic (The Important Part)

void loop() {
  // Looking for RFID cards
  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) {
    cardDetected = true;
    waitingForPassword = true;
    Serial.println("Card detected! Please enter password:");
  }
}

This constantly checks for cards. When it finds one, it reads the unique ID and asks for a password. Two-factor security!

Password Checking

if (key == '#') {
  // Check if password is correct
  if (enteredPassword == correctPassword) {
    Serial.println("Password CORRECT! GPIO 26 ON");
    passwordEntered = true;
  } else {
    Serial.println("Password INCORRECT! Try again:");
    enteredPassword = "";
  }
}

When someone hits '#', I check if they entered "1234" (my default password). Right password = access granted. Wrong password = try again!

The Equipment Control

// Only turn on equipment if BOTH conditions are met
bool shouldActivate = cardPresent && passwordEntered;
digitalWrite(OUTPUT_PIN, shouldActivate ? HIGH : LOW);

This is the heart of my security system. Equipment only gets power when someone has both a valid card AND entered the correct password. Remove either one and it shuts off immediately.

User Interface

void updateDisplay() {
  if (!cardPresent) {
    display.println("Place card near reader");
  } else if (waitingForPassword) {
    display.println("Enter Password:");
    display.print("Pass: ");
    for (int i = 0; i < enteredPassword.length(); i++) {
      display.print("*");  // Security - show asterisks
    }
  } else if (passwordEntered) {
    display.println("ACCESS GRANTED");
    display.println("Machine: Running");
  }
}

The display always tells users what's happening and what they need to do next. And yes, passwords show up as asterisks for security!

How Someone Actually Uses It

1. Walk up to equipment, see "Place card near reader"
2. Hold RFID card near the reader
3. Screen changes to "Enter Password:" with asterisks as you type
4. Enter "1234" and press '#'
5. If correct: "ACCESS GRANTED" and equipment powers up
6. When done: remove card and everything shuts off instantly

1. ORGINAL File for pcb design files Final pcb design
2. ORGINAL code i used makergate test code