Solar powered audio unit

I’m looking to create a small solar powered audio unit which will play a track when one of 4 buttons are pushed (different track for each button).The unit will be housed in an aluminium structure (yet to be designed) around 1500mm tall. The idea is that these units will be placed in fairly remote locations, so relatively fuss free, long lasting power and heat (from the battery charging and environmental) are key considerations. I’ve put together a little mud map of what I think might be an option. I wondering if the members of this forum could cast an eye over it to let me know if I’m on the right track, or barking up the wrong tree.
Please be kind, I’m very new to electronics and definitely punching outside my weight division in this area.
Thanks in advance for your help.
Audio Unit.pdf (3.4 MB)

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Hi Jeff. Welcome to the forums.
So cool! :confetti_ball:
What is the model of the speaker will you be using?
Does it have an in build pre-amp/amplifier? Does it expect line level audio?

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Hey Pixmusix, Thanks for the reply.
I’ve attached the spec sheet for the speaker, pretty sure there is no pre-amp/amp.
Line level audio?.. excuse my ignorance, is that the quality of the audio? At a rough guess, an average mp3 track would run for a minute or less at a bit rate of 192kbps.
Hope this helps.
C0604B.pdf (489.8 KB)


Hi Jeff,

Welcome to the forum, I can see Pixmusix has already dived onto the audio end so I know you are in safe hands there. Solar powered projects can be a bit of a pain to get going but we’re here to help you along the way. I can already see that you have a pretty solid idea of what you are doing with your diagram there.

Adafruit themselves have some resources on wiring up the panel and battery that may be of interest as a sanity check. Otherwise I will leave the audio bit to the hands of the professionals.

Keep us posted, I am looking forward to seeing the end result.

Hi Jeff
Just checked the product Wiki. Firstly in your diagram the speaker connection is incorrect. It should be connected across “SPK1” and “SPK2” not to ground (according to diagram in Wiki). Don’t know what you are going to do about volume control (IO_1 and IO_2). Maybe what you get at switch on is OK??

Apparently it plays straight off an SD card so forget about Pre-amp, Line level audio etc, everything should be taken care of.

I would hold off on a solar panel until you know what power is required. I don’t see too much (zero in fact) published along these lines so you might have to build it up and measure. 2W might be enough, I have no idea.
Cheers Bob


That’s gonna be perfect :slight_smile: Nice one!
Because your speaker doesn’t have a pre-amp you don’t need to worry about * line level *.
Edit : @Robert93820 beat me to it! :sweat_smile:


Thanks everyone for your help and input, I’ll post some images during development.

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