Thursday 8 December 2016

Christmas Celebrations - chocolate box LEDs with music

Nothing says "Christmas" like a box of Celebrations - especially one that plays Christmassy music and is lit with LEDs.

Untitled

I've finished the code so that it now randomly chooses one of fifteen snippets from different Christmas songs to play while the LEDs gently pulse. With the addition of some jumper wires you can now choose from several sets of Poundland LEDs in different styles and colours.

Merry Christmas LEDs
Christmas Celebrations

If you want to look at the code, here it is:


Sunday 27 November 2016

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.

  Jumper wires

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:

Tuesday 1 November 2016

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.

Halloween lights

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.

Halloween lights

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.

Halloween lights

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