The Spectacle Audio Board allows you to add sound from a microSD card to your Spectacle projects. Each board accepts a microSD card with sounds in .ogg format, and has a 1/8" (3.5mm) audio jack line-level output ready to be amplified. It is important to know that the files used by the Spectacle Audio Board must be in OGG Vorbis format. This free codec has a higher compression ratio than MP3 and, more importantly, can be used without paying a licensing fee to any third-party organization. We use the free, open source program Audacity to convert from whatever the file’s current format is to OGG Vorbis.
The Audio Board is equipped with three 3.5mm TRRS jacks: two for Spectacle control signals from a Director Board and one for an amplified speaker. The one labeled “In” should be plugged into a board that is closer to the Director Board than the Audio Board is, or into the Director Board itself. Make sure to pay attention to the directionality of the jacks, as they will dictate how your Spectacle modules speak with one another and with the Director Board. As with every other Spectacle module, you will need the Director Board to operate any Spectacle project.