Christmas celebration lights

At the end of my previous post I set a list of potential improvements to the Little Box of Horrors I'd made for Halloween.

This is the list..

• At the moment it plays the same sound every time the button is pressed, but it'd be nice to play a random selection from a playlist of sounds
• The lights could flicker and flash while the sound plays instead of being constantly on
• If the sounds are of varying lengths the lights should only be on for as long as each sound plays
• The lights and sounds could be swapped for Christmas or other gaudily celebrated occasions
• Spray paint and decorate the box to be a bit less chocolate-boxy
• Re-write it in gpiozero

Earlier this week I'd a pleasant afternoon cutting and soldering wires. I cut the connections between the Raspberry Pi and the LEDs and soldered jumper wires on so they're now swappable.

 

I also returned to Poundland and got a couple of packs of Christmas LEDs. As with the Halloween lights I cut the battery boxes off and soldered jumper wires to the ends, taking care to use red or black jumpers to indicate the polarity of the connections. Now I can choose Christmas or Halloween lights for the box.

Having had fun with hardware I thought I'd better have another go at the code, so I've re-written it in GPIO Zero, and discovered as a bonus that it's really easy to control the LEDs with PWM so you can make them gently pulse on and off.

So in a couple of sessions I've crossed three items off my list!

• At the moment it plays the same sound every time the button is pressed, but it'd be nice to play a random selection from a playlist of sounds
• The lights could flicker and flash while the sound plays instead of being constantly on
• If the sounds are of varying lengths the lights should only be on for as long as each sound plays
• The lights and sounds could be swapped for Christmas or other gaudily celebrated occasions
• Spray paint and decorate the box to be a bit less chocolate-boxy
• Re-write it in gpiozero

Here's the code:

Little box of horrors - Halloween hacking with pound shop LED lights

Inspired by Les Pounder's hacking, I spent a quid on some LED pumpkin lights and thought I'd make something fun for the trick-or-treaters this year. I wanted the lights to come on and a spooky sound effect to play when a button is pressed on my little box of horrors.



As Les suggested I removed the battery box from the LEDs, and then extended the wires with some hook up wire. I also found and edited some nice spooky sfx, which I saved onto the Zero.

The Raspberry Pi Zero has no audio output, so I added a pHAT DAC from Pimoroni; remembering to use extended headers so I could later add a ProtoZero board to tidily solder the wires onto.



For the first prototype I connected the LEDs to a GPIO pin and the ground pin and started by writing some code that just made them come on and then go off again after a few seconds. Next I added a button which switched the lights on. Finally I used Pygame mixer to play the audio file at the same time as the lights come on.

The code looks like this:

	# Import Python libraries
	import RPi.GPIO as GPIO
	import time
	import pygame
	# Set the GPIO caming convention
	GPIO.setmode(GPIO.BCM)
	GPIO.setwarnings(False)
	# Set the GPIO pins for button input and LED output
	GPIO.setup(3, GPIO.IN, pull_up_down = GPIO.PUD_DOWN)
	GPIO.setup(24, GPIO.OUT)
	pygame.mixer.init()
	pygame.mixer.load("Laugh.wav")
	while True:
	if(GPIO.input(3) ==0):
	GPIO.output(24, GPIO.HIGH)
	pygame.mixer.music.play()
	time.sleep (10)
	GPIO.output(24, GPIO.LOW)
	GPIO.cleanup

I went back to my favourite Instructable on launching Python scripts at startup and then set about cramming it all - including USB powered speakers and a USB power bank - into a Celebrations box that I'd kept because it looked useful. I drilled a small hole in the side to pass the LED's wires through, and a big hole in the lid for an arcade button. It's a bit of a squeeze to get to the lid on, but it all just about fits in.



There are plenty of things I could do to make this better. For instance...

• At the moment it plays the same sound every time the button is pressed, but it'd be nice to play a random selection from a playlist of sounds
• The lights could flicker and flash while the sound plays instead of being constantly on
• If the sounds are of varying lengths the lights should only be on for as long as each sound plays
• The lights and sounds could be swapped for Christmas or other gaudily celebrated occasions
• Spray paint and decorate the box to be a bit less chocolate-boxy
• Re-write it in gpiozero