With the hardware assembled you're ready to load sounds on the Audio FX board. First make sure you've read the Audio FX board guide to audio files are copied to the board. Then connect the Audio FX board's USB micro connector to your computer or laptop. You should see your computer mount the Audio FX board as a USB mass storage device.
Next you'll want to gather some sound files to copy to the Audio FX board. I found some scary scream sound effects on archive.org, such as:
- Wilhelm Scream - This is a classic scream that's used in almost every horror film!
Make sure to download the Ogg Vorbis or WAV versions of the sound effects. The Audio FX board can't play other formats like MP3.
Since there's only one trigger from the PIR sensor to the Audio FX board, you probably want to use the randomization feature of the board to play a random scream or other scary sound. To use randomization rename all your files to the format:
TxxRANDn.OGG or TxxRANDn.WAV
Where xx is the number of the trigger input on the audio board and n is a number from 0 to 9 to identify up to 10 sound files that will randomly be chosen for playback. In my case I'm using Audio FX input number 5 and have 5 sound effects so my files look like:
Once you've copied the files to the Audio FX board eject the drive from your computer and unplug the device. Now turn on the battery power and you will likely hear the sound effects play for a moment as the PIR sensor starts up. Close the box and try opening it. Surprise! You should hear a random scream! The PIR sensor will continue to play screams until you close the box and it stops detecting motion.
If you don't hear screams make sure the speaker is turned on and that you can see the green power LED on the Audio FX board. When the PIR sensor detects motion and triggers a sound you should see a red LED on the Audio FX board turn on. If you don't see the red LED turn on or hear the sound, then you might need to adjust the PIR sensor sensitivity. Check out the PIR guide for more details on adjusting the sensitivity. You can also play with the retriggering and delay time on the PIR sensor to have it play for longer or shorter times.
That's all there is to building the Halloween scream box project! Try scaring unsuspecting friends or coworkers by putting the box on your desk. Or you can even mount the hardware under someone's desk to really give them a fright when they sit down! Have fun and happy Halloween!