The Pi Zero Mass Storage Picture Frame

The Raspberry Pi Zero – and the not-perpetually-out-of-stock Raspberry Pi A+ – only have one USB port, but behind that port is a lot of functionality. This is an OTG USB port, and just like the USB port on your smartphone, this little plug can become any kind of USB device. Transforming the Pi into a USB gadget allows it to be a serial connection, MIDI device, audio source or sink, or a USB mass storage device.

[Francesco] was especially interested in the USB mass storage capability of the Raspberry Pi Zero and built a small project to show off its capabilities. He turned a Pi Zero into the controller for a digital picture frame, constantly displaying all the image files on a small screen.

The build started with [Andrew Mulholland]’s guide for Pi Zero OTG modes, with just a few modifications. When the Pi is plugged into a PC, it automatically becomes a 100 Megabyte USB storage device. You don’t need that much space on a digital picture frame, anyway.

While setting up a digital picture frame is easy enough, there’s still a tremendous amount of untapped potential in using the Pi Zero as a USB gadget. With enough buttons, switches, and sensors, the Pi can become a wearable MIDI device, or with the Pi camera module, an IP webcam. Neat stuff, and we can’t wait to see what the community comes up with next.

39 thoughts on “The Pi Zero Mass Storage Picture Frame

  1. I’m really not sure what’s been achieved here aside from plugging in a USB cable.

    The pi zero as a USB gadget is well documented. The hack didn’t manage to modify the files displayed to the picture frame from the pi.

    I think MTP would be required instead of mass storage, not sure if picture frames support that though.

    1. Some picture frame displays, and bigger ones including laptops and monitors panels, can be driven by controller boards commonly sold on Ebay or Aliexpress. Letting the PI directly drive one of those panels would be awesome.
      Alternatively one can use one of those controller boards, but then they must be programmed to interface to the specified panel and the programming board requires a parallel port.
      Example: http://www.ebay.com/itm/121111355258

      Could a PI become a LCD panel driver or at least become a programmer for a driver board?
      Surely a lot of work is involved, but not an impossible task IMO. That would be a real hack.

      Yes, there definitely is demand: old picture frames are uber cheap at flea markets over here.

      1. Can’t *quite* manage USB gadget mode yet, though; the dwc2 driver doesn’t let you override the host/device mode. That’s needed because the OTG id pin is tied to ground on the A+. There’s a small patch to fix it, but it looks like it’s going to have to get into the Pi kernel via linux mainline, which will probably take a while.

          1. It’s not stupid, it’s just only useful in a few niche situations. I’m putting a Pi+camera inside a laser cutter, and it’d be ideal to just have it connected/powered/serving images via USB. I’d really rather not stick a whole B+ in there if I can get it working with an A+ I have surplus. And I’m doing a bunch of computer vision stuff on board, so a dumb camera isn’t an option.

  2. I would love to experiment with the PI-Zero but, there are no PI-Zeros available from legitimate suppliers for $5. They are scooped up by opportunists and sold on eBay for $35 to $45. Sorry I’m not playing that game’

    1. I agree.
      It was introduced with great fan fair then became unobtainable. It is disappointing it is taking so long for them to be on sale. I have a couple of projects the small size is an asset for. But I don’t want to have to pay the exorbitant prices for the addons I don’t want or need. I do wonder if the “$5” Pi Zero will ever appear again.

      1. They’re out there. I got both of mine from MicroCenter. I got my first Zero about a week after they were released thanks to someone not coming in to pick up the one they had reserved online for in-store pick-up. I was there for other stuff but started a conversation with the salesman who told me of the expired reservations at customer service. I got my second one just a couple weeks ago because I was at MicroCenter for random stuff again and who couldn’t use another 5$ Zero? My MicroCenter is currently soldout again, but I know for sure that they had ’10+ In Stock’ for well over a week.

        I understand the frustration of Starter Packs but try to understand… it’s a $5 Pi. Profit margin can’t be all that high to start with then you factor in 2nd and 3rd hand sellers… they have to make a profit somehow even if it’s just to afford the box and tape to mail it in- packing it in with a power supply and a couple of adapter cables allows them to squeeze a couple extra dollars out of it to make it worth their while to sell.

        There should have been a 5 board minimum for online orders since that would have effectively made it into a $25 minimum order. Probably would have meant several more Zeros on fleaBay… but whatever, as far as I’m concerned that’s up to the buyer to reconcile their own foolishness for participating in such a thing. My hope is that with an established minimum the sellers would be less inclined to focus on ‘packs’.

        Wow… it feels good to write a comment on a legit keyboard for a change instead of a phone-keyboard.

    2. Agreed; even Adafruit is playing this game. Their listing for the bare Pi Zero had been out of stock for months, but every week or two they’re selling the Starter packs — if you want $5 worth of peripherals for an extra $25 on the pricetag.

      1. Couldn’t tell you. It’s the reason I’m still sadly without one. I’d happily pay $15 or more just for the form factor — if that’s what it actually costed and not just an unreasonable vendor mark-up. Maybe they should’ve just announced a higher price from the start, then let it drop over time.

    1. I agree. They have three official stockists and the only one of those three that exists in my part of the word don’t even bother to put it on their website so obviously they have never sold a single unit.

      This is NOT a distribution system it’s a buddy system were a select few get access to Pi Zero’s.

      So effectively they have said to people in my part of the world “well Fu(k you”.

      So now the more I read about any Pi, the more I hate them.

    2. I have 2.

      …didn’t even try, really. Both times it was like… ‘I’m here, it’s here… meh, I’ll spend more than $5 on gas getting home. Sure… might as well…’

  3. They were just available at adafruit yesterday, and microcenter’s also restocked….. They are hard to get but if you are watching pretty easy. I’ve gotten two at the Cincinnati microcenter and could have gotten more multiple times they’ve had them in stock….

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