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Eben Upton: An educational life of Pi (The H)

Eben Upton: An educational life of Pi (The H)

Posted Dec 21, 2012 5:09 UTC (Fri) by gmaxwell (guest, #30048)
Parent article: Eben Upton: An educational life of Pi (The H)

This comment may be a little off-topic but all the exclusive attention on the Pi frustrates me a bit. It's a very limited piece of hardware: the SoC is uses spends almost all of it's transistors on the videocore unit which is basically not useful to the FOSS world. (Unfortunate— as I understand that it's a pretty neat and highly flexible architecture, but entirely proprietary)

The arm core is rather slow for what it is— cache deprived and an older microarch it is clock for clock much slower than the current fast arm stuff in tablets today while running at lower clock and with only a single core. People are often trying to ask it to do more than it realistically can.

Sometimes this is because they're unaware that there are alternatives in similar form factors for somewhat higher prices which are enormously faster, such as http://www.hardkernel.com/renewal_2011/products/prdt_info... (quad core 1.7ghz 2gb ram, $89) which would better suit some of these applications. (though indeed, the pi does seem to be king for applications where price trumps all other considerations— including the openness of the platform— and yet you still can't use an actual micro-controller).


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Eben Upton: An educational life of Pi (The H)

Posted Dec 21, 2012 9:33 UTC (Fri) by rvfh (subscriber, #31018) [Link]

Would be nice to have a ARMv7 single- or dual-core board for about $30 with network + USB... Beaglebones are nice but a bit dear for my application...

Eben Upton: An educational life of Pi (The H)

Posted Dec 21, 2012 13:07 UTC (Fri) by pboddie (guest, #50784) [Link]

The Olimex OLinuXino products look rather promising in this area:

https://www.olimex.com/Products/OLinuXino/

There's also the Cubieboard:

http://cubieboard.org/

Eben Upton: An educational life of Pi (The H)

Posted Dec 23, 2012 16:34 UTC (Sun) by dlang (subscriber, #313) [Link]

they are interesting ideas, but they need to actually ship.

One of the massive advantages that the Pi has right now is that it's being produced in high volume.

When you're building 10K units/day you can get significantly better pricing than when you are trying to build 200 units total.

If these products actually get manufactured (in anything other than a one-off batch of prototypes), then we can start considering them as options

It would be good to get competition to the Pi (competition is good to have, it keeps all the projects from stagnating), but right now there's not much anywhere close to the price point.

Eben Upton: An educational life of Pi (The H)

Posted Dec 24, 2012 20:38 UTC (Mon) by BlueLightning (subscriber, #38978) [Link]

The OLinuXino has shipped, I bought and received one months ago (the MAXI iMX233-based one at least).

Eben Upton: An educational life of Pi (The H)

Posted Dec 29, 2012 15:20 UTC (Sat) by dr@jones.dk (subscriber, #7907) [Link]

We are tracking exactly this area for the FreedomBox - you might wanna subscribe to that wiki page and/or contribute to it: https://wiki.debian.org/FreedomBox/TargetedHardware

Btw reason we don't include RPi on that list is that none of us working on FreedomBox consider it relevant for our purpose: It has too much non-free parts and is too slow (at least when used with official Debian where it needs to use the classic non-hardfloat amrel port).

Eben Upton: An educational life of Pi (The H)

Posted Jan 5, 2013 19:34 UTC (Sat) by pboddie (guest, #50784) [Link]

I wrote some notes up on this kind of thing here: http://wiki.fsfe.org/Hardware_Vendors#Single-Board_Computers

Incidentally, I was at your talk on the FreedomBox at FSCONS 2012 where you placed a great deal of emphasis on self-maintaining solutions, and I think that this is another area where the Raspberry Pi people should be reaching out and actively collaborating with initiatives like the FreedomBox project instead of just seeing which party will give them the goodies first. For example, Oracle seem rather interested in pushing Java-based educational solutions on Raspberry Pi, but I don't think it would be wise to let them run the show.

Certainly, the Raspberry Pi has triggered a cascade of low price devices capable of running Linux and acting as PC replacements, although there were already similar devices available, and with statements being made about how the focus is to "tack back towards our founding aims", I can understand how people might be a bit suspicious of the project's priorities and motivations. After all, teaching programming is something that can be done without a specific device being made available, and surely the existing initiatives in this area would benefit from more attention and, of course, a share of the free, favourable publicity showered on Raspberry Pi by the mainstream media.

Then again, just getting everyone to work together that should be working together is an exercise in itself.

Eben Upton: An educational life of Pi (The H)

Posted Dec 21, 2012 9:34 UTC (Fri) by epa (subscriber, #39769) [Link]

It may be slower than the latest tablets but that still makes it as fast as a desktop PC of 10-15 years ago, which I recall being more than adequate for most applications.

Eben Upton: An educational life of Pi (The H)

Posted Dec 21, 2012 9:45 UTC (Fri) by renox (subscriber, #23785) [Link]

Unfortunately your criticisms about the Pi's GPU are also true for all the alternatives: ARM's GPUs are all with proprietary firmware/drivers..
There are reverse engineering projects, but AFAIK they're not mature yet.
I think that the biggest issue is for video, as the ARM CPUs are not especially fast you need the GPU acceleration for smooth video decoding.

Eben Upton: An educational life of Pi (The H)

Posted Dec 21, 2012 16:42 UTC (Fri) by gmaxwell (guest, #30048) [Link]

Eh, it's not exactly the same. Videocore is pretty unlike most GPUs, its a proprietary DSP architecture and has been sold as a standalone only processor in many devices— I was a little surprised to see people start calling it a "GPU". The design differences mean that general GPU reverse engineering work is unlikely to be that useful against the PI's chip. For the rPi the device boots from the videocore and you must have a rather gigantic binary blob just to get the kernel loaded on the arm, even if you're not using video out.

AFAIK on most arm single board computers with proprietary GPUs if you're not using the video out you don't need any proprietary gpu code.

A closer comparison would be the TMS320C64x+ in some of the omap4 chips. It is also used for video decode with blobby codecs, but in its case there is an open toolchain, public specifications, (resulting in a) nice Theora port to it, and you still don't boot via it. (Though it isn't also used as the system's general GPU)

> It may be slower than the latest tablets but that still makes it as fast as a desktop PC of 10-15 years ago, which I recall being more than adequate for most applications.

Ah, well it's slower than many think even by that comparison— the machines you are comparing it to weren't driving 1080p displays, decoding realtime, compressed media, running N layers of inefficient interpreted code. Some of the expectations are different, and I've personally had some frustration where people showed up trying to get my software running on Pis— software which is many times realtime on faster arm SBCs— frustrated and having a hard time.

There is certainly a place for slow low power machines and having some more pressure against unnecessary bloat is great, but I think the gap (esp in terms of awareness) in options between quite-slow at $30 and a dozen times faster at $150 seems to be pushing people to Pi when their needs really require something a bit faster and could tolerate a slightly higher price point.

Eben Upton: An educational life of Pi (The H)

Posted Dec 22, 2012 8:13 UTC (Sat) by tuna (guest, #44480) [Link]

Haven't there been pretty good progress from the SOC people lately? It seems like a lot of boards at least have the Linux driver (not the OpenGL/Gallium side) open.

Pi > Pi

Posted Dec 21, 2012 11:37 UTC (Fri) by david.a.wheeler (subscriber, #72896) [Link]

I share your concern. I will say that a lot of the things they're talking about doing will help not only the current Pi, but potential future Pis and any similar SoC on Linux. Per the interview: "Everything the Foundation produces or endorses in the educational area will be CC licensed, and to the best our our ability we'll be producing stuff which is applicable not just to the Pi but to any Linux-based teaching platform, whether that's another small-board computer like the Pi or an x86 desktop." That applies not just to the educational materials, but also to stuff like the various ways to make it more CPU-efficient.

Eben Upton: An educational life of Pi (The H)

Posted Dec 23, 2012 16:45 UTC (Sun) by dlang (subscriber, #313) [Link]

That $89 machine you link to doesn't have gpio connections to drive devices

yes, its somewhat annoying to see headlines of the type "<person> is doing <standard thing> with a RASPBERRY PI"

On the other hand, these headlines are leaking out past the tech community, and as a result, we are getting exposure to people who didn't realize you could do <standard thing> on your own.

In any case, price is a fairly significant feature on it's own. At this price point they very nearly become throwaway devices, something you can just hand out to interested folks or have people get as impulse buys.

When you talk about devices costing 3-5x this, it becomes much more of a "Do I really need this" discussion.

the Pi lets you do things that you could do with a micro-controller, without the horrible expense of buying a development kit (which most manufacturers still price for engineers who are having their company buy them, not for hobbyists). The fact that it can be used for 'normal' computer things and then extended to micro-controller things is a nice camel's nose situation.

they did a good job of keeping to their goals and creating a device that nicely bridges the micro-controller and computer space, it's not the best for either, but it's frequently 'good enough', especially to get people started

Eben Upton: An educational life of Pi (The H)

Posted Jan 5, 2013 19:52 UTC (Sat) by pboddie (guest, #50784) [Link]

If you're a hobbyist buying a microcontroller kit that needs an expensive development kit then you're most likely buying the wrong thing. At one point I considered cataloguing the different microcontroller solutions that are friendly to the average Free Software host or which provide a Free Software toolchain, but with so many decent, reasonably priced products out there, it would have been a huge task.

For example, all of the Arduino solutions (based on both AVR and ARM) use development tools that are Free Software, and you can even ignore the Processing-based IDE and use gcc if you want. Browsing around various online stores yields products using other microcontrollers that also seem to be supported by Free Software and which don't cost hundreds of dollars just to get started.

I'll agree with you that the Raspberry Pi is probably more convenient than something like Arduino for developing and deploying embedded software, but there are plenty of people who will justifiably argue that you aren't really doing microcontroller or truly embedded work at that point but are instead doing the kind of interfacing that used to happen a lot more back in the early days of the microcomputer era. Not that this is a bad thing if that's what you really want to do, of course.

Eben Upton: An educational life of Pi (The H)

Posted Jan 5, 2013 23:32 UTC (Sat) by dlang (subscriber, #313) [Link]

Given that the Pi folks are explicitly looking back at the early microcomputer era (the C-64 in particular) as a guideline, the fact that the Raspberry Pi looks very much like that means they succeed :-)

I think there's also a lot of value in having a computer that can easily interface with hardware devices rather than just a microcontroller.

Doing simple things is simple on both devices, but then when you want to start doing UI and network type things, having a complete OS and related toolsets available is much better than having to try and rebuild the base functionality on a microcontroller.

Now, if you need thousands of devices, then the cost difference becomes a driving factor, but for one-off projects, learning, and experimentation, going the full computer route is a good approach.


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