Best price to capacity for low power storage

May 14, 2018 10:29 AM

I'm building a battery powered suitcase jukebox for trips to the place we go that doesn't have Internet access. What is the most low power storage I can get for around $200?

The brain is a Raspberry Pi running Moode with a HiFiBerry DAC. This limits me to USB attached storage. Because it's running off batteries, power consumption is a consideration. The budget is somewhat arbitrary.

I am completely comfortable putting together whatever adapters are needed to go from the storage to USB. I can do JBOD or RAID. Read times aren't very important. Write times aren't a consideration at all.

posted by donpardo to Technology (8 answers total)

Best answer: I would guess SD cards storage is going to have the best price per MB and be the lowest power consumption. Spinning disks are going to pull way more current.

I found a 512GB SD card for under $200 ($194)

I can't find any big & slow SD storage probably because there's no market for it - people generally want big cards for hi-def video which requires high speeds.

You can get no-name 256GB microsd cards for like $30 or less but man I do not trust those things. They seem to get bad reviews on Amazon too.

You can get 128 GB cards for ~$40 so it's a tiny bit less expensive, but it looks like pricing is pretty close to linear at these larger sizes and to save the hassle I'd just but the 512GB card if it was me.
posted by GuyZero at 10:40 AM on May 14, 2018 [2 favorites]

Best answer: If you're in the USA, Costco has a 512GB SSD USB 3.0 external hard drive for $149
posted by blob at 11:07 AM on May 14, 2018

I suspect that SD is the best format; at some point, the limiting factor for audio is no longer storage space. At 100MB/hour (decent quality MP3, and if you're making a battery powered boombox, probably better quality than you need), a bog-standard 128 GB SD card available anywhere for $40 stores 53 days of music. At 15 songs per hour, that's almost 20,000 songs which means that your weak point will probably either be the interface to pick one of the 20,000 songs or the metadata to power the interface rather than not having enough music. (As GuyZero notes, you could get one that is four times the size, if you actually do have 80,000 songs and want to listen to 200+ days of music). And with SD, you can always expand to a larger one later if you need, as the prices come down.
posted by Homeboy Trouble at 11:32 AM on May 14, 2018 [1 favorite]

Just throwing this out there, but which model of pi are you using? I ask because the 0 uses much less power than the full size models which might save you enough juice to justify an ssd via usb. You can get a ~1TB ssd drives for just under $200 nowadays.

In terms of capability, I use a 0-w to drive an mpd server in my shop which I then control using an app on my phone and it works great. I don't know how that would compare to moode in features/speed.
posted by Poldo at 11:35 AM on May 14, 2018 [2 favorites]

Response by poster: Guy: SD CARDS! I'm so used to them being 16GB they never crossed my mind. If I mount it read only it should last pretty much forever.

Blob: might pick that up regardless.

Poldo: That's a good suggestion and I'll keep it in mind. I'm using a B (I think. It's upstairs and I'm lazy). I already have it and the DAC, so that's what I'm using for now.

Homeboy: you don't want to know. I've got 5TB of music, mostly lossless, which is too much. I'm building my own enclosures for the speakers inside the suitcase, so I hope to do a little better than boombox quality.
posted by donpardo at 3:55 PM on May 14, 2018

Response by poster: Poldo: which mpd client do you use?
posted by donpardo at 3:55 PM on May 14, 2018

Best answer: There's a SanDisk sale on Amazon today - a 256GB USB drive for about $50

You've got at least 2 USB ports depending on the board model so this is about as good a deal as you're likely to get.
posted by GuyZero at 7:48 AM on May 15, 2018 [1 favorite]

Best answer: On my phone I use MPDroid. I also had a very lightweight web client called ympd running on the pi directly but I almost never used it so I got rid of it. I also use a small python script (using the musicpd library) to handle a few buttons and a tiny OLED status display for when messing with a touch screen isn't convenient.

Besides energy use another potential benefit of the pi0w (or a 3) over a 2 is that the built in wifi chip is really very good. It's able to connect and stay connected without a range extender, even in my shop which is right at the limit of my router's range.
posted by Poldo at 10:43 AM on May 15, 2018