6.3 Interactive Alarm System ============================== Build your own **professional emergency siren** with flashing lights and authentic alarm sounds! Ever wondered how police cars, ambulances, and fire trucks create those attention-grabbing warning signals? Now you can create your own mini version! **What makes this special?** This isn't just a simple beeper - it's a sophisticated alarm system with **3 different professional modes**: - šŸŒŠ **Sweep Mode**: Like a tornado siren with gradually rising pitch - šŸ’“ **Pulse Mode**: Like a heartbeat monitor with rhythmic beeps - āš” **Rapid Mode**: Like emergency vehicle flashers with quick bursts **Real-world applications:** Perfect for security projects, emergency simulations, attention-getting devices, or just impressing friends with realistic sound effects! **šŸŽÆ Project Highlights:** - šŸŽµ **3 Professional Sound Modes**: Choose from Sweep, Pulse, or Rapid alarm patterns - šŸ’” **Synchronized Light Show**: LED brightness changes match the sound patterns - šŸŽ›ļø **Easy Control**: Simple slide switch to activate/deactivate the alarm - šŸ”Š **Authentic Effects**: Uses PWM to create realistic emergency vehicle sounds - āš™ļø **Smart Programming**: Interactive mode selection at startup **šŸ”§ How the Magic Works:** **šŸŽšļø The Control System:** - **Slide Switch (GP17)**: Your on/off control with stable switching (thanks to the capacitor filter) - **Sound Generator (GP15)**: Controls the transistor that powers the buzzer - **Light Controller (GP16)**: Makes the LED flash and dim in sync with sounds **šŸŽµ The Sound Science:** The passive buzzer can play different frequencies - like a tiny musical instrument! By changing the frequency rapidly, we create: - **Rising Sirens**: Start low, sweep high (like tornado warnings) - **Pulse Beats**: Quick on-off patterns (like medical monitors) - **Rapid Alerts**: Fast flashing patterns (like emergency vehicles) **šŸ’” The Light Show:** The LED brightness is controlled by PWM (Pulse Width Modulation) - think of it as a digital dimmer switch that can change brightness hundreds of times per second to create smooth effects! Component List ^^^^^^^^^^^^^^^ - Raspberry Pi Pico W x1 - MicroUSB cable x1 - 830 Tie-Points Breadboard x1 - LED x1 - Transistor S8050 x1 - Resistor 220Ī©, 1kĪ©, 10kĪ© x1 - Passive Buzzer x1 - Capacitor 104 x1 - Slide Switch x1 - Jumper Wire Several Connect ^^^^^^^^^ .. image:: img/3.connect/6.3.png Code ^^^^^^^ .. note:: * Open the ``6.3_interactive_alarm_system.py`` file under the path of ``Ultimate-Starter-Kit-for-Pico-W\Python\1.Project`` or copy this code into Thonny, then click "Run Current Script" or simply press F5 to run it. * Don't forget to click on the "MicroPython (Raspberry Pi Pico)" interpreter in the bottom right corner. .. 6.3.png Get ready for an exciting **interactive alarm experience**! Here's your step-by-step guide: **šŸš€ Step 1: Choose Your Alarm Style** When you run the program, you'll see a professional menu asking you to select an alarm mode. Simply type **0**, **1**, or **2** and press Enter: - **Type 0** for Sweep Mode (gradual frequency sweep) - **Type 1** for Pulse Mode (on/off pulsing) - **Type 2** for Rapid Mode (fast flashing) You'll hear a confirmation beep after making your selection! **šŸŽµ Step 2: Test Each Mode** (Try them all!) - **Mode 0 (Sweep)**: Like a tornado siren - starts low and sweeps to high pitch šŸŒŖļø - **Mode 1 (Pulse)**: Like a medical monitor - rhythmic beeps with flashing šŸ’“ - **Mode 2 (Rapid)**: Like police flashers - quick bursts of sound and light āš” **šŸŽ›ļø Step 3: Control Your Alarm** - **Slide switch LEFT** = Alarm ON (sirens blaring, lights flashing!) - **Slide switch RIGHT** = Alarm OFF (peaceful silence) - **Note**: Your switch might be wired opposite - just try both directions! **šŸŽŖ Step 4: Enjoy the Show!** Watch how the LED brightness perfectly synchronizes with the sound patterns. Each mode creates a completely different audio-visual experience! **šŸ’” Pro Tips:** - Try switching modes and comparing the different effects - Show friends and let them guess which emergency vehicle each mode sounds like - Use in a dark room for the best visual effect - The system remembers your mode until you restart the program The following is the program code: .. code-block:: python import machine import time # Hardware Pin Constants BUZZER_PIN = 15 LED_PIN = 16 SWITCH_PIN = 17 # PWM and Frequency Constants LED_PWM_FREQUENCY = 1000 BUZZER_DUTY_CYCLE = 30000 # Alarm Effect Constants EFFECT_STEPS = 100 EFFECT_INCREMENT = 2 EFFECT_DELAY_MS = 10 # Sound Frequency Range MIN_FREQUENCY = 130 MAX_FREQUENCY = 800 # LED Brightness Range MIN_BRIGHTNESS = 0 MAX_BRIGHTNESS = 65535 # Alarm Modes MODE_SWEEP = 0 MODE_PULSE = 1 MODE_RAPID = 2 # Initialize hardware components buzzer = machine.PWM(machine.Pin(BUZZER_PIN)) led = machine.PWM(machine.Pin(LED_PIN)) led.freq(LED_PWM_FREQUENCY) switch = machine.Pin(SWITCH_PIN, machine.Pin.IN) # Global variables alarm_active = False alarm_mode = MODE_SWEEP def stop_buzzer(pwm_pin): """Turn off the buzzer by setting duty cycle to zero""" pwm_pin.duty_u16(0) def play_tone(pwm_pin, frequency): """Play a tone at specified frequency on the buzzer""" pwm_pin.freq(frequency) pwm_pin.duty_u16(BUZZER_DUTY_CYCLE) def map_value(x, in_min, in_max, out_min, out_max): """Map a value from one range to another""" return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min def sweep_alarm_effect(): """Create a sweeping alarm effect with gradual frequency and brightness change""" for step in range(0, EFFECT_STEPS, EFFECT_INCREMENT): if not alarm_active: break # Calculate LED brightness and buzzer frequency brightness = int(map_value(step, 0, EFFECT_STEPS, MIN_BRIGHTNESS, MAX_BRIGHTNESS)) frequency = int(map_value(step, 0, EFFECT_STEPS, MIN_FREQUENCY, MAX_FREQUENCY)) # Apply effects led.duty_u16(brightness) play_tone(buzzer, frequency) time.sleep_ms(EFFECT_DELAY_MS) def pulse_alarm_effect(): """Create a pulsing alarm effect with on/off cycles""" # High intensity pulse led.duty_u16(MAX_BRIGHTNESS) play_tone(buzzer, MAX_FREQUENCY) time.sleep_ms(200) # Off period led.duty_u16(MIN_BRIGHTNESS) stop_buzzer(buzzer) time.sleep_ms(100) def rapid_alarm_effect(): """Create a rapid flashing alarm effect""" # Quick flash sequence for _ in range(5): if not alarm_active: break led.duty_u16(MAX_BRIGHTNESS) play_tone(buzzer, MIN_FREQUENCY + MAX_FREQUENCY // 2) time.sleep_ms(50) led.duty_u16(MIN_BRIGHTNESS) stop_buzzer(buzzer) time.sleep_ms(50) def run_alarm_effect(): """Execute the appropriate alarm effect based on current mode""" if alarm_mode == MODE_SWEEP: sweep_alarm_effect() elif alarm_mode == MODE_PULSE: pulse_alarm_effect() elif alarm_mode == MODE_RAPID: rapid_alarm_effect() def turn_off_alarm(): """Turn off both buzzer and LED""" stop_buzzer(buzzer) led.duty_u16(MIN_BRIGHTNESS) def display_mode_selection(): """Display mode selection menu""" print("\n" + "="*50) print(" ALARM SIREN LAMP - MODE SELECTION") print("="*50) print("Available alarm modes:") print(" 0 - Sweep Mode (Gradual frequency sweep)") print(" 1 - Pulse Mode (On/off pulsing)") print(" 2 - Rapid Mode (Fast flashing)") print("-"*50) def select_alarm_mode(): """Allow user to select alarm mode at startup""" global alarm_mode mode_names = ["Sweep", "Pulse", "Rapid"] while True: display_mode_selection() try: user_input = input("Please select mode (0-2): ").strip() mode = int(user_input) if 0 <= mode <= 2: alarm_mode = mode print(f"\nāœ“ Mode selected: {mode} ({mode_names[mode]})") # Mode confirmation beep play_tone(buzzer, 500 + mode * 200) time.sleep_ms(200) stop_buzzer(buzzer) print(f"Alarm system is ready in {mode_names[mode]} mode!") print("Toggle the switch to activate the alarm.") print("To change mode, restart the program.\n") return else: print("āŒ Invalid mode! Please enter 0, 1, or 2\n") except ValueError: print("āŒ Invalid input! Please enter a number (0-2)\n") except KeyboardInterrupt: print("\n\nProgram interrupted by user. Goodbye!") turn_off_alarm() # Ensure everything is turned off raise SystemExit def switch_interrupt_handler(pin): """Handle switch state changes for alarm on/off control""" global alarm_active alarm_active = pin.value() mode_names = ["Sweep", "Pulse", "Rapid"] if alarm_active: print(f"šŸšØ Alarm activated - Mode: {mode_names[alarm_mode]}") # Startup confirmation beep play_tone(buzzer, 1000) led.duty_u16(MAX_BRIGHTNESS // 2) time.sleep_ms(100) turn_off_alarm() time.sleep_ms(50) else: print("āœ… Alarm deactivated") turn_off_alarm() # Main program starts here def main(): """Main program function""" print("\nšŸšØ ALARM SIREN LAMP SYSTEM šŸšØ") print("Copyright 2024 - IoT Alarm Project") # Let user select the alarm mode select_alarm_mode() # Configure switch interrupt for both rising and falling edges switch.irq(trigger=machine.Pin.IRQ_RISING | machine.Pin.IRQ_FALLING, handler=switch_interrupt_handler) print("šŸ”„ System running... (Press Ctrl+C to exit)") try: # Main program loop while True: if alarm_active: run_alarm_effect() else: turn_off_alarm() time.sleep_ms(50) # Small delay when inactive except KeyboardInterrupt: print("\n\nšŸ‘‹ Program stopped by user") turn_off_alarm() print("All devices turned off. Goodbye!") # Run the main program if __name__ == "__main__": main() Phenomenon ^^^^^^^^^^^ .. video:: img/5.phenomenon/6.3.mp4 :width: 100%