SparkFun Forums

[GabrielQ]

I volunteer at a museum where a new exhibit was recently added using the Lilypad MP3 and sensors to playback audio clips pertaining to dates on a timeline. I did not design the exhibit but I installed it, and originally had headphones used for the playback. After some use, it's become evident that headphones are not ideal, and speakers would be more desirable, but speakers that have enough volume and frequency response to be heard clearly this installation. I was going to get a small usb powered set of speakers until upon further reading learned that plugging into an amplifier from the headphone jack could be detrimental. The board's power terminals are wired to a usb plug n is being powered by a usb charger. I wanted to use the same charger to power the speakers... Is that a small enough amplifier to be considered safe? If not, what are my options? Thanks.

[darrellg]

If the onboard 1W amp is not sufficient to power a speaker directly, section 3.2 of the document at https://www.sparkfun.com/datasheets/Wid ... output.pdf shows a simple circuit using two resistors and one capacitor per channel that will allow you to use powered speakers.

[GabrielQ]

Thanks, but that document doesn't give the specs of the capacitors to be used, any idea on that?

[darrellg]

10uF seems to be what the other boards using that series of decoder chips are using.