WEEK 14

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#include < SPI.h >
#include < Wire.h>
#include < Adafruit_GFX.h>
#include < Adafruit_SH110X.h>

// I initialized the 128x64 OLED display using the I2C protocol structure
Adafruit_SH1106G display = Adafruit_SH1106G(128, 64, &Wire, -1);

// Hardware pin mapping for my custom PCB routing
const int LED_PIN = D9;      // Actuator output pin
const int PIR_PIN = D10;     // Sensor input pin

int lastPirState = LOW;      // I stored the previous state to filter redundant serial logs

void setup() {
    // I opened the serial channel at 115200 bps to synchronize with my Python GUI
    Serial.begin(115200);
    
    // I configured the data direction for my digital pins
    pinMode(LED_PIN, OUTPUT);
    pinMode(PIR_PIN, INPUT); 
    
    // I forced a low state to guarantee the LED starts completely turned off
    digitalWrite(LED_PIN, LOW); 

    // I mounted the OLED using its default 0x3C I2C address and printed a boot message
    display.begin(0x3C, true); 
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SH110X_WHITE);
    display.setCursor(0, 0);
    display.print("System Ready...");
    display.display();
}

void loop() {
    // --- TASK 1: REAL-TIME SENSOR SAMPLING ---
    int currentPirState = digitalRead(PIR_PIN);

    // I implemented state-change detection to prevent flooding the USB buffer
    if (currentPirState != lastPirState) {
        if (currentPirState == HIGH) {
            Serial.println("MOTION_DETECTED");
        } else {
            Serial.println("NO_MOTION");
        }
        lastPirState = currentPirState; // I updated the history register
    }

    // --- TASK 2: SERIAL COMMAND PARSING ---
    if (Serial.available() > 0) {
        // I captured incoming strings up to the newline delimiter
        String command = Serial.readStringUntil('\n');
        command.trim(); // I stripped any residual whitespaces

        // I isolated incoming text payloads targeting the OLED screen
        if (command.startsWith("TXT:")) {
            String mensaje = command.substring(4); // I trimmed the prefix token
            display.clearDisplay();
            display.setCursor(0, 10);
            display.setTextSize(2); // Set to size 2 for better UI scanning
            display.print(mensaje);
            display.display();
        } 
        // Discrete commands received from the Python interface buttons
        else if (command == "RED_ON") {
            digitalWrite(LED_PIN, HIGH);
        } 
        else if (command == "RED_OFF") {
            digitalWrite(LED_PIN, LOW);
        }
    }
    
    delay(20); // I added a 20ms threshold to stabilize the execution loop
}
    

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import sys
import serial
from PyQt6 import QtWidgets, QtCore
from frontend import Ui_MainWindow  

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self):
        super().__init__()
        self.setupUi(self)
        
        # I established the USB serial link at 115200 bps matching the microcontroller configuration
        try:
            self.serial_port = serial.Serial('/dev/cu.usbmodem101', 115200, timeout=1)
            print("Serial Connection Established Successfully!")
        except Exception as e:
            print(f"Error al conectar con la placa: {e}")

        # I mapped the interface button interaction signals to their respective handler functions
        self.btn_led_red_on.clicked.connect(self.turn_led_on)
        self.btn_led_red_off.clicked.connect(self.turn_led_off)
        
        # I linked the click event of the submit button to route the text inputs toward the OLED
        self.btn_enviar_oled.clicked.connect(self.enviar_a_oled)

        # I configured a non-blocking background background timer running on a 100ms cycle
        self.timer = QtCore.QTimer()
        self.timer.setInterval(100) 
        self.timer.timeout.connect(self.read_serial_data)
        self.timer.start()

    # I transmitted the activation instruction payload encoded as raw bytes
    def turn_led_on(self):
        if hasattr(self, 'serial_port') and self.serial_port.isOpen():
            self.serial_port.write(b"RED_ON\n")
            print("Serial Data Sent: RED_ON")

    # I transmitted the deactivation instruction payload encoded as raw bytes
    def turn_led_off(self):
        if hasattr(self, 'serial_port') and self.serial_port.isOpen():
            self.serial_port.write(b"RED_OFF\n")
            print("Serial Data Sent: RED_OFF")

    # I captured the dynamic text string from the input widget and sent it with the control prefix token
    def enviar_a_oled(self):
        texto = self.oled_screen.text()
        if texto and hasattr(self, 'serial_port') and self.serial_port.isOpen():
            comando = f"TXT:{texto}\n"
            self.serial_port.write(comando.encode())
            print(f"Serial Data Sent: TXT:{texto}")

    # I continuously polled the hardware buffer data stream to catch incoming sensor triggers
    def read_serial_data(self):
        if hasattr(self, 'serial_port') and self.serial_port.isOpen():
            if self.serial_port.in_waiting > 0:
                try:
                    # I intercepted the line string data and translated the bytes back to text characters
                    data = self.serial_port.readline().decode('utf-8').strip()
                    
                    # I evaluated the data packet strings and updated the CSS style sheet parameters dynamically
                    if data == "MOTION_DETECTED":
                        self.lbl_movimiento.setText("MOTION DETECTED")
                        self.lbl_movimiento.setStyleSheet("color: #ff4d4d; font-weight: bold;") 
                    elif data == "NO_MOTION":
                        self.lbl_movimiento.setText("NO MOTION")
                        self.lbl_movimiento.setStyleSheet("color: #ffffff;") 
                except Exception as e:
                    print(f"Error leyendo serial: {e}")

    # I added a safe termination function to release the USB hardware resource when the application closes
    def closeEvent(self, event):
        if hasattr(self, 'serial_port') and self.serial_port.isOpen():
            self.serial_port.close()
        event.accept()

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec())