W.A.S.A.P.P

Parts List

• RaspberryPi Pico W (with headers)
• 30–33mm Arcade push button
• Power supply for the Pico (AAA battery bank or LiPo)
• Dupont cables
• Computer with a speaker (for the server)

Programming

1. Set up the Flask server

   Install Flask on your computer if you haven't already, then create the server file below. Replace path/to/audio.mp3 with the path to your Wilhelm scream (or other audio file). if you need a copy of the scream, you can download it from here

   Python — doorbell_server.py Copy

   # Run with: python doorbell_server.py
   # Trigger with: curl -X POST http://localhost:5000/play_audio
   
   from flask import Flask
   import os
   
   app = Flask(__name__)
   
   @app.route('/play_audio', methods=['POST'])
   def play_audio():
       os.system('aplay path/to/audio.mp3')
       return 'Audio played', 200
   
   if __name__ == '__main__':
       app.run(host='0.0.0.0', port=5000)

   pip install Flask

2. Install MicroPython on the Pico W

   Download the latest MicroPython .uf2 firmware from micropython.org, hold the BOOTSEL button while plugging in the Pico, then drag the file onto the drive that appears.

3. Flash the Pico W firmware

   Create a new file on the Pico W (e.g. using Thonny) and paste the code below. Replace the Wi-Fi credentials and SERVER_IP with your server's local IP address.

   MicroPython — main.py Copy

   import network
   import urequests
   import machine
   import time
   
   # Wi-Fi credentials
   SSID = 'your_wifi_ssid'
   PASSWORD = 'your_wifi_password'
   
   # Button on GPIO 14
   button = machine.Pin(14, machine.Pin.IN, machine.Pin.PULL_UP)
   
   # Connect to Wi-Fi
   wlan = network.WLAN(network.STA_IF)
   wlan.active(True)
   wlan.connect(SSID, PASSWORD)
   
   while not wlan.isconnected():
       time.sleep(1)
   
   print('Connected to Wi-Fi')
   
   url = 'http://SERVER_IP:5000/play_audio'
   
   def play_audio():
       try:
           response = urequests.post(url)
           print('Response:', response.text)
       except Exception as e:
           print('Failed to send request:', e)
   
   while True:
       if not button.value():  # Button pressed (active low)
           play_audio()
           time.sleep(1)  # Debounce delay

Assembly & Enclosure

For the enclosure, I repurposed an old project box and drilled holes for the button and cables. The Pico W is mounted inside with hot glue, and the button is connected to GPIO 14 and GND using dupont wires. You can customize the enclosure however you like – 3D printing, laser cutting, or even a vintage tin box would work great!

Testing & Usage

With everything set up, press the arcade button and enjoy the dramatic Wilhelm scream echoing through your home! You can further customize the system by adding more buttons for different sounds, integrating with smart home devices, or even creating a web interface to trigger the sounds remotely.