Les Pounder has posted the third part of his Tiny FX series at Pimoroni’s Learn site, this time on adding audio to a build. It covers two approaches: generating simple tones on the board for a two tone emergency vehicle siren, and playing a WAV file from onboard storage.

The WAV project pairs a speaker with LED dots to recreate the siren and flashing lights of the Ghostbusters ECTO 1. A MicroPython module handles the lighting animation and audio playback together, triggered by the BOOT button in the centre of the Tiny FX board. The code sits in a try-finally block so the board shuts down cleanly when the script ends.

Audio files go in an sfx directory on Tiny FX’s 4MB of onboard storage, uploaded through Thonny’s file pane. The guide uses a 16-bit, 11025 Hz mono WAV. Higher quality works, but the files get bigger, and the output is mono anyway. Audacity is suggested for recording or trimming your own. The walkthrough takes about 45 minutes.

See more at learn.pimoroni.com.