Author Topic: Full computer for $25  (Read 31991 times)

Re: Full computer for $25
« Reply #50 on: February 29, 2012, 01:36:03 pm »
erm, in my experience, it doesn't always work.

Depends on what is driving the HDMI out.
<i>Marmite slave</i>

Re: Full computer for $25
« Reply #51 on: February 29, 2012, 01:40:17 pm »
... and out of interest how would one set it up to perform operations with keyboard using TV screen as monitor?
Just plug them in.

If you've got a modern TV with an HDMI connector it's trivial, since the board has an HDMI connector on it.  Alternatively it has a composite output (on a phono), so that can probably be plugged into a lot of other, older TVs (via a SCART connector for example, with a simple cable).

So long as the keyboard is USB, you should just be able to plug that directly into the USB connector.  It won't work with a PS/2 style keyboard connector, but a cheap USB keyboard is probably £5, slightly more if you want a better quality device.

What would you see on screen, after selecting the appropriate AV slot..?
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Woofage

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Re: Full computer for $25
« Reply #52 on: February 29, 2012, 01:43:03 pm »
erm, in my experience, it doesn't always work.

Depends on what is driving the HDMI out.

A monitor with DVI i/p
Pen Pusher

Re: Full computer for $25
« Reply #53 on: February 29, 2012, 01:45:37 pm »
erm, in my experience, it doesn't always work.

Depends on what is driving the HDMI out.

A monitor with DVI i/p
I meant the HDMI transmitter that takes the signals from the SoC, and the driver in the SoC that is outputting the signal to the HDMI transmitter.

Like I said, in my experience, it depends on these things.
<i>Marmite slave</i>

Re: Full computer for $25
« Reply #54 on: February 29, 2012, 01:49:47 pm »
What would you see on screen, after selecting the appropriate AV slot..?

That depends upon what you put onto the boot SD card - if you put a Linux distro on it it'll boot into that.
An Android port is being worked upon too, assuming that completes then it'll show that on the display. There's no reason why someone shouldn't write a BBC or Spectrum emulator and have it start up showing the relevant prompt ready for you to start typing in a BASIC program  :)

As a basic embedded system board it won't by default do anything, which is what might disappoint a lot of non-geeks thinking that they are getting a really cheap computer...  (edit to add: I've seen some people on consumer bargain forums asking if it'll run Windows  :facepalm: )

Re: Full computer for $25
« Reply #55 on: February 29, 2012, 01:53:11 pm »
erm, in my experience, it doesn't always work.

Depends on what is driving the HDMI out.

A monitor with DVI i/p
I meant the HDMI transmitter that takes the signals from the SoC, and the driver in the SoC that is outputting the signal to the HDMI transmitter.

Like I said, in my experience, it depends on these things.

Good point but the spec says it will drive DVI from the hdmi output, so it should be fine.
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dasmoth

  • Techno-optimist
Re: Full computer for $25
« Reply #56 on: February 29, 2012, 01:53:50 pm »
edit to add: I've seen some people on consumer bargain forums asking if it'll run Windows  :facepalm: )

Windows 8 supports ARM.  I've not seen final hardware requirements, but wouldn't be shocked to see it running on a RPi.

(RAM is going to be tight...)
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Re: Full computer for $25
« Reply #57 on: February 29, 2012, 01:58:00 pm »
I'm not sure I completely follow all of this, but would I be reasonably close in thinking that with USB peripherals (keyboard/mouse) and a monitor with either an HDMI input, or suitable conversion, this little gizmo can run linux well enough to act as a web-browsing box?

David Martin

  • Thats Dr Oi You thankyouverymuch
Re: Full computer for $25
« Reply #58 on: February 29, 2012, 01:58:41 pm »
Finally got an order in - probably arrive some time in April.

I would imagine some factories in China ordering new stocks of Glee (for had rubbbing of course!)

..d
"By creating we think. By living we learn" - Patrick Geddes

David Martin

  • Thats Dr Oi You thankyouverymuch
Re: Full computer for $25
« Reply #59 on: February 29, 2012, 01:59:30 pm »
I'm not sure I completely follow all of this, but would I be reasonably close in thinking that with USB peripherals (keyboard/mouse) and a monitor with either an HDMI input, or suitable conversion, this little gizmo can run linux well enough to act as a web-browsing box?
Yes.
If you plug in wireless periperals and connect to a spare channel on your TV then you have a home TV/PC combo.

..d
"By creating we think. By living we learn" - Patrick Geddes

Woofage

  • Ain't no hooves on my bike.
Re: Full computer for $25
« Reply #60 on: February 29, 2012, 02:10:59 pm »
I'm not sure I completely follow all of this, but would I be reasonably close in thinking that with USB peripherals (keyboard/mouse) and a monitor with either an HDMI input, or suitable conversion, this little gizmo can run linux well enough to act as a web-browsing box?

As DM wrote, yes. It's like a smart phone in terms of its grunt but with hi-def video capability, AIUI.
Pen Pusher

Re: Full computer for $25
« Reply #61 on: February 29, 2012, 02:25:15 pm »
Well, there are smartphones and there are smartphones.


It's a lot slower processor than the current top-end smartphones (which also have HD capability).

It's also a lot cheaper.
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redshift

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Re: Full computer for $25
« Reply #62 on: February 29, 2012, 04:24:49 pm »
For those with severe nostalgia, I believe the RISCOS guys are going to support it, and there used to be a really good Beeb emulator for that.
L
:)
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dasmoth

  • Techno-optimist
Re: Full computer for $25
« Reply #63 on: February 29, 2012, 04:28:06 pm »
For those with severe nostalgia, I believe the RISCOS guys are going to support it, and there used to be a really good Beeb emulator for that.

Oooh, thanks for the heads-up.  Did wonder about RISC OS, but assumed that the hardware was just toooo much different from Acorns of yore...

(What's the probability of old games running on a machine without something that looks like a VIDC?)
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Panoramix

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Re: Full computer for $25
« Reply #64 on: February 29, 2012, 04:31:10 pm »
Can you power it from a dynamo and post on yacf from the comfort of your bicycle? Ideally you want some voice recognition software.
Chief cat entertainer.

David Martin

  • Thats Dr Oi You thankyouverymuch
Re: Full computer for $25
« Reply #65 on: February 29, 2012, 04:34:59 pm »
Can you power it from a dynamo and post on yacf from the comfort of your bicycle? Ideally you want some voice recognition software.
I should imagine so but only if your name is Kim.
"By creating we think. By living we learn" - Patrick Geddes

dasmoth

  • Techno-optimist
Re: Full computer for $25
« Reply #66 on: February 29, 2012, 04:35:06 pm »
Can you power it from a dynamo and post on yacf from the comfort of your bicycle? Ideally you want some voice recognition software.

I don't see why not.  On the other hand, as already pointed out the hardware is pretty close to what you'd find in the guts of a smartphone, but the phone adds some moderately sophisticated power management circuitry, plus a nice LiPo battery so you don't need to reboot every time you stop at a junction.

"Siri, start new post to YACF"?
Half term's when the traffic becomes mysteriously less bad for a week.

Panoramix

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Re: Full computer for $25
« Reply #67 on: February 29, 2012, 04:38:35 pm »
I am trying to think of cool things that an "amateur" could do with it. At the moment I can only think of drones and robots but there must be other applications!
Chief cat entertainer.

Re: Full computer for $25
« Reply #68 on: February 29, 2012, 04:42:26 pm »
It would make a good base module for a web-interface-controlled central heating control, plus cameras. Heck of a lot cheaper than anything commercially available.
<i>Marmite slave</i>

dasmoth

  • Techno-optimist
Re: Full computer for $25
« Reply #69 on: February 29, 2012, 04:57:09 pm »
I'm not actually convinced it's going to be the best choice for robotics and similar "engineering" projects.  Sure, you can probably hook most things up via the USB ports if you put your mind to it, but there are other cheap devices available with better built-in capabilities for low-level IO.  I don't see these things encroaching on Arduino territory, for instance.

RPis win if you're going to use the video outputs.  It's got plenty of power to build rich UIs.  We'll see it showing up in a bunch of status displays, office dashboards, etc.  Grab some data over the network (or from a USB sensor), format it nicely, and display it for only marginally more than the cost of the screen.
Half term's when the traffic becomes mysteriously less bad for a week.

David Martin

  • Thats Dr Oi You thankyouverymuch
Re: Full computer for $25
« Reply #70 on: February 29, 2012, 05:18:09 pm »
Couple this with the Gertboard (an ATMega328 based IO board) and you have the best of both worlds. A web enabled multithreaded OS, and a hardware solution that can be near RT. Or even piggyback an Arduino on it (with associated power level issues).

Doing web stuff on an arduino is possible but makes it hard to do other things as well. The RPi has hardware IO interfaces but they will not be real time so may not be good enough for robot/drone control alone. 
"By creating we think. By living we learn" - Patrick Geddes

Re: Full computer for $25
« Reply #71 on: February 29, 2012, 06:50:58 pm »
I seem to recall that some of the connectors do have General Purpose IO lines on them, but of course the RPi website is down at the moment, so I can't have a hunt around to remind myself exactly how it's configured.

The Broadcom Data Sheet for the SOC does state that there are 54 general purpose IO lines, but virtually all of those have alternate functions.  I'm hoping that they'll have sensibly connected GPIO lines whose secondary functions either aren't available, or aren't likely to be useful, to some of the connectors, so they're available for random experimentation.

Of course, there aren't likely to be that many lines, and some may more usefully be used connected up to SPI or I2C devices (and you can hang simple IO line devices off of these buses as well).

The Gertboard is likely to be useful if you want something a bit more tolerant of poor handling, or which needs a chunkier about of drive, but I'm quite happy to deal with 3.3V IO lines, and not destroy them with ESD and whatnot.

Any Realtime issues with the board are more likely to relate to Linux than the actual hardware.  With careful selection of what's running, and the appropriate kernel configurations, it'll likely be broadly OK as a realtime OS.

Alternatively, you can always port something like RTEMS across onto it (I've already suggested this to one of my colleagues!).
Actually, it is rocket science.
 

andygates

  • Peroxide Viking
Re: Full computer for $25
« Reply #72 on: February 29, 2012, 06:53:36 pm »
Well, first of all I'm going to do a media centre, which will get all my, er, media off my crappy PC screen and onto my telly.  The old XP lappy doesn't have the grunt.  Here's XBMC rocking the raspberry goodness:

http://webcache.googleusercontent.com/search?q=cache:DLubtCGttW4J:www.raspberrypi.org/archives/571+raspberry+pi+media+centre&cd=5&hl=en&ct=clnk&gl=uk&client=firefox-a

(google cache of the swamped page)

I can see the community coming up with a whole wave of "onna stick" standard goodies.  It's in a dinky niche between Arduino and ordinary computers, small and sippy enough to be very portable indeed (helmets, balloons, space!) and not as scary to newbies as duino boards. 
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simonp

  • Omnomnomnipotent.
Re: Full computer for $25
« Reply #73 on: March 01, 2012, 01:31:44 am »
Part of the value of the Pi will be giving people something they can experiment on that’s reasonably powerful. You can buy all sorts of USB stuff to plug in e.g. sensors etc. If you develop something clever on it, then you can re-work if you can turn it into a product. It’s a great way to get people messing about, and it’s massively more powerful than the Atmel ARM based system I’ve messed about with and a fraction of the price for a dev kit - and much easier to talk to, as well.

Re: Full computer for $25
« Reply #74 on: March 01, 2012, 08:14:44 am »
Exactly, it's powerful enough that it can run stuff like Spark, as well as real development environments for people who get that far.  It's relatively cheap, so that schools, and for that matter, anyone who wants to have an experiment, can, and even if they destroy the device, it's not the end of the world.

Arduino's, and their clones, are a great way of getting cheap microcontrollers out there, but the development of them is a little intimidating for anyone use to the handholding of your average Windows app.

It does strike me, that the cost of monitors is now going to become a significant one, because even a cheap monitor to use with this device is going to be £100 or so (five times the price of its controller).  I guess one of the advantages is, that it's relatively unlikely that any monitors could be easily damaged or destroyed using a Raspberry Pi, whereas the front end electronics could easily be killed by ESD or some electronic oversight.
Actually, it is rocket science.