Ask HN: Does a Solar Powered MP3 player/FM transmitter exist?

#1

Post by hearseguy » Thu, Oct 26, 2023, 5:06 AM UTC

Looking for a Solar Powered/charged MP3 player with integrated FM transmitter (part 15 legal). I have found various incarnations that are no longer available. Has anyone run across or know of anything close to this ideal? I’d rather not reinvent the wheel if possible, but looking not to just get something munged together.

Use case is a off grid Museum self guided tour. One idea is to set them up around a ghost town so people can tune in and hear a bit of its history and stories.

I have successfully used the Raspberry Pi transmitter and solar battery as a proof of concept, and have found kits [0] and parts [1] that can be pieced together. I do well enough to produce a prototype but lack the skills to create something that would stand the test of time.

Where would you all recommend to get something like this created? Also it’s important to me to keep it as open source as possible.

[0] https://learn.adafruit.com/minty-mp3/hardware [1] https://www.adafruit.com/product/1958

Re: Ask HN: Does a Solar Powered MP3 player/FM transmitter exist?

#2

Post by solardev » Thu, Oct 26, 2023, 5:17 AM UTC

I don't quite understand your use case here, but can't you just get any DC or USB compatible FM transmitter (like for cars) and MP3 player or old smartphone, hook them up to a modern solar charged battery and be done? Anker makes both the battery packs and the solar chargers, as do GoalZero, Jackery, and others.

In other words, the playback device, transmitter, battery, solar charger, and solar panel can all be different parts. These days it's common to get the battery and charger together in one unit. But the rest of things tend to evolve separately and you can get much better quality for a given price by separating them than by trying to find an all in one setup (which wouldn't have the square area to charge a good sized battery anyway). If you want a few days of autonomy through low sun periods, it's really the battery that's doing the job, not the solar panel so much.

Or if it's for a self guided tour, can't the visitors provide their own smartphones? All you'd need to provide is an app with geofencing or QR codes or even signs labeling the stops.

Am I missing your point?

Re: Ask HN: Does a Solar Powered MP3 player/FM transmitter exist?

#3

Post by hearseguy » Thu, Oct 26, 2023, 10:48 AM UTC

solardev wrote: post #2

I don't quite understand your use case here, but can't you just get any DC or USB compatible FM transmitter (like for cars) and MP3 player or old smartphone, hook them up to a modern solar charged battery and be done? Anker makes both the battery packs and the solar chargers, as do GoalZero, Jackery, and others. In other words, the playback device, transmitter, battery, solar charger, and solar panel can all be diffe…

Thank you for your response. Yes, I can and have munged existing components together to create what I'm after. The problem is it's not an ideal solution, and would require more maintenance it realistically should, the return on investment isn't there.

This problem has been previously solved for some reason the product(s) no longer exist, and I wanted to see if I was missing a glaringly obvious solution. I understand it's a niche product that scratches my own itch, and doesn't need mass market appeal.

Cell and smartphone coverage may not and doesn't exist in some of the areas I'm considering. Every vehicle comes with a radio that can be spontaneously used to hear a broadcast and not rely on a coverage map. I can create a podcast distribute it that way, that suffers from similar issues but, maybe it's the way to go.

Re: Ask HN: Does a Solar Powered MP3 player/FM transmitter exist?

#4

Post by solardev » Thu, Oct 26, 2023, 1:55 PM UTC

hearseguy wrote: post #3

solardev wrote: post #2

I don't quite understand your use case here, but can't you just get any DC or USB compatible FM transmitter (like for cars) and MP3 player or old smartphone, hook them up to a modern solar charged battery and be done? Anker makes both the battery packs and the solar chargers, as do GoalZero, Jackery, and others. In other words, the playback device, transmitter, battery, solar charger, and solar panel can all be diffe…

Thank you for your response. Yes, I can and have munged existing components together to create what I'm after. The problem is it's not an ideal solution, and would require more maintenance it realistically should, the return on investment isn't there. This problem has been previously solved for some reason the product(s) no longer exist, and I wanted to see if I was missing a glaringly obvious solution. I understand…

I'm still not 100% clear what you want to make, but it sounds like one of those self guided driving tours?

If so, have you checked out apps like GuideAlong or ShakaGuide? The idea is that you'd download the tour beforehand (just a few MB of audio) and then from there on it's just the GPS doing the work. No cell coverage needed. I just used one of those in a national park last week, where there was no cell coverage. It worked very well and would be more precise and user friendly than FM radio (whose range is harder to gauge than geofencing).

Sorry if I still misunderstood. Just spitballing here.

Re: Ask HN: Does a Solar Powered MP3 player/FM transmitter exist?

#5

Post by hearseguy » Thu, Oct 26, 2023, 4:15 PM UTC

solardev wrote: post #4

hearseguy wrote: post #3

Earlier quoted context omitted.

Thank you for your response. Yes, I can and have munged existing components together to create what I'm after. The problem is it's not an ideal solution, and would require more maintenance it realistically should, the return on investment isn't there. This problem has been previously solved for some reason the product(s) no longer exist, and I wanted to see if I was missing a glaringly obvious solution. I understand…

I'm still not 100% clear what you want to make, but it sounds like one of those self guided driving tours? If so, have you checked out apps like GuideAlong or ShakaGuide? The idea is that you'd download the tour beforehand (just a few MB of audio) and then from there on it's just the GPS doing the work. No cell coverage needed. I just used one of those in a national park last week, where there was no cell coverage. I…

No worries, thanks for the response. Yes, similar to those types of tours. I'll see if I can link to one of the older products previously mentioned.

Re: Ask HN: Does a Solar Powered MP3 player/FM transmitter exist?

#6

Post by hearseguy » Thu, Oct 26, 2023, 6:04 PM UTC

solardev wrote: post #4

hearseguy wrote: post #3

Earlier quoted context omitted.

Thank you for your response. Yes, I can and have munged existing components together to create what I'm after. The problem is it's not an ideal solution, and would require more maintenance it realistically should, the return on investment isn't there. This problem has been previously solved for some reason the product(s) no longer exist, and I wanted to see if I was missing a glaringly obvious solution. I understand…

I'm still not 100% clear what you want to make, but it sounds like one of those self guided driving tours? If so, have you checked out apps like GuideAlong or ShakaGuide? The idea is that you'd download the tour beforehand (just a few MB of audio) and then from there on it's just the GPS doing the work. No cell coverage needed. I just used one of those in a national park last week, where there was no cell coverage. I…

Here's a link to one of the discontinued products for reference:

https://usb.brando.com/usb-solar-charger-with-mp3-player-and...