Blog/20131123 Raspberry Pi as OER4Schools reader

From Bjoern Hassler's website
Jump to: navigation, search

More from B's blog:

Some older entries are here.

Raspberry Pi as OER4Schools reader

I've been busy this week making an offline version of OER4Schools resource. We've put this onto memory sticks. For the next round, we'll make branded lanyards and get more sturdy sticks. The branded lanyards is not just for promotion, but it also clearly identified the stick, meaning that it's less likely to be lost, or for theft.

However, what can you do about a playback device? The memory sticks would work in a computer, and you could connect them to a smart phone with an OTG cable as well. The OTG cables are pretty cheap (£1.50), so it's worth sending them, for people to use with their smart phones or tablets where they have then.

But what about a whole device for playback? Tablets are pretty versatile, and getting cheaper and cheaper. Unbranded tablets (7", 4-8 GB) seem to be starting from around £40, but when we looked at cheap unbranded tablets a while ago for ANTSIT, there was a high failure rate. The cheapest branded 7" tablets seem to start around £99, e.g. with the previous generation Kindle Fire HD available. I haven't investigated how closely it's tied to Amazon, but the net reckons that it can be rooted. Tablets shipping with Android as default start perhaps around £130-140 (e.g. Samsung Galaxy Tab or Asus), up to the new Nexus 7 at £199. iSchool.zm is starting to sell tablets for around £150 I believe, and this is straight in Zambia, with warranty, which is an extremely attractive propostion. (Though at present it's not clear how general purpose these tablets will be.)

So what about Raspberry Pi? Comparing a Raspberry Pi to a tablet, is not quite like for like. For starters, the tablet is more of an integrated device, in many cases made for reading and watching movies, while the Raspberry Pi is really for experimentation. At the same time, the Raspberry Pi is used by many people to make cheap devices (such as NAS devices).

So what could we do with a Raspberry Pi. This needs to be as cheap as possible, with as few components as possible. Typical prices seem to be

  • Raspberry Pi (£33)
  • SD card (we'd need 8GB) (£5)

So far, that's not looking bad, though it's close to the cheapest tablet. However, my hunch would be that we'd get better reliability out of a Raspberry Pi at this rate. The Raspberry Pi comes in a case, which is good. I had wondered about just getting the board and wrapping it in celophane, but the lack of heat dispersion might cause a problem.

The question is what other bits are essential, or what could be found in the field. Extras would cost around this:

  • Power supply (£3.50)
  • AV cabling, e.g. rca to rca for use with TV (£2), hdmi-vga for use with monitor or projector (£5.50), audio (£3.50)
  • Keyboard (£3), mouse (£2.50)

Some of these bits may well be available to people. I suspect that you'd have to have a power supply and an HDMI-VGA cable with the package, as these would be hard to find. I think the use of a TV is just too low resolution for reading, though it would work for watching the videos. With VGA, it may be possible to find an old VGA monitor or projector, e.g if you were using our resource in college. And this is a big assumption about the Raspberry Pi approach: I am assuming that a monitor can be found somewhere. But I don't think that's totally unreasonable (especially in a college setting). There may well be old monitors around, or maybe one could work with a charity on this.

We also need an input device. For a customised Raspberry Pi setup, one might be able to get away with just a mouse / numeric keypad for just reading our resource, but mouse / keyboard are so cheap that it doesn't seem worth designing software that would work with say a mouse only. (Though you'd get far with a mouse alone.) Or perhaps with some sort of media centre approach, using the pins on the Raspberry Pi. One could also consider having some PS2 adaptors handy, so that older devices could be used. The problem with keyboard is that they are bulky, so from my perspective of trialling technologies in the field that's a pain.

In any case, the total stands at

33 + 5 + 3.50 + 5.50 + 3.50 + 2 = 52.50 

so far. Wifi would add about £7 (though we would start to run out of USB ports, and would need a hub as well), and a larger SD card (16GB) about £5, bringing the cost up to £65. That's still cheaper than a tablet, but we are making the assumption that we will be able to find a screen in the field, e.g. at a school for teacher professional develoment, or at a college.

One good thing would be for the SD card to be partitioned, so that the contents (our resource) can be in a FAT32 partition, that can be used on a laptop as well. Ideally the OS partition needs to be read-only, so that it can't corrupt.

So where does that leave us? There is a difference in price, particularly if some cabling / screens etc are around already. I think it would be worth testing this. Also, being a component system, while it requires perhaps more skill, broken bits can be swapped out, which is an advantage over tablets. Often cheap tablets don't have a good upgrade path, as the OS changes very rapidly, and hardware needs to keep up. This may (or may not) be different for the Raspberry Pi, but perhaps the platform will stay as it is for a few years.

On the whole, I think we might want to do a trial. Perhaps partner with a second hand computer charity in Zambia, and see whether we can use existing stuff with Raspberry Pi.



2013-11-23 | Leave a comment | Back to blog Share on Twitter Share on Facebook