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by ross
Thu Feb 19, 2015 11:40 am
Forum: Off topic discussion
Topic: Embedded low-latency decoding with analogue output
Replies: 5
Views: 1472

Re: Embedded low-latency decoding with analogue output

It might be worthwhile looking at this thread ( http://www.raspberrypi.org/forums/viewt ... 43&t=93615 ) where it seems that people have either 250 msec or 150 msec end-to-end RPi camera -> h/w encoder -> network -> h/w decoder -> screen.
by ross
Thu Feb 12, 2015 10:51 am
Forum: Advanced users
Topic: Pi B 2 Processors - follow on
Replies: 6
Views: 1840

Re: Pi B 2 Processors - follow on

Can somebody please explain why I don't get the other processors showing in 'top' Run 'top', and then press '1' to toggle between the two views: top - 10:50:24 up 23 min, 1 user, load average: 0.00, 0.01, 0.04 Tasks: 83 total, 1 running, 82 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.0 us, 0.2 sy, 0.0...
by ross
Fri Jan 30, 2015 12:35 am
Forum: HATs and other add-ons
Topic: Gert's VGA add-on for the B+
Replies: 240
Views: 118435

Re: Gert's VGA add-on for the B+

Can you describe what configuration / data (if any) you are setting up the panel with over I2C? Do you have a URL for the datasheet? (ideally the one with the command set of the panel) My first guess is that trying to toggle any "display invert set" command might help (a W.A.G. of sending command 20...
by ross
Thu Jan 29, 2015 5:21 pm
Forum: Advanced users
Topic: ARM V6 ( cpu of raspberry pi ) in sleep mode
Replies: 3
Views: 986

Re: ARM V6 ( cpu of raspberry pi ) in sleep mode

The ARM has the WFI and WFE instructions: - http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka13332.html - http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15473.html ... but this is a question better suited to the 'Bare metal' forum. In Linux you should read throu...
by ross
Thu Jan 29, 2015 4:16 pm
Forum: Advanced users
Topic: Upstream Kernel Compilation, no USB on B+
Replies: 2
Views: 1863

Re: Upstream Kernel Compilation, no USB on B+

Glad that you managed to find a working combination of options. I thought that I would add another reason why USB might not work when using the the bcm2835_defconfig in case somebody else tries to reproduce this Unlike the Foundation's "bcm2708" platform the upstream "bcm2835" does not switch on the...
by ross
Thu Jan 29, 2015 11:36 am
Forum: Advanced users
Topic: No /proc/device-tree on self-compiled kernel
Replies: 6
Views: 4514

Re: No /proc/device-tree on self-compiled kernel

Copied linux/arch/arm/boot/zImage (and linux/arch/arm/boot/Image in a separate attempt) to /boot/kernel.img There appears to be an extra step in the middle that isn't necessarily obvious without careful reading of the device-tree documentation (it is easy to miss) https://github.com/raspberrypi/doc...
by ross
Fri Jun 15, 2012 5:20 pm
Forum: Camera board
Topic: CSI camera/DSI display
Replies: 23
Views: 31793

Re: CSI camera/DSI display

I believe:
- the iPhone4 rear sensor is a 5Mpix Omnivision OV5650.
- the iPhone4S rear sensor is an 8Mpix Sony IMX145.
by ross
Tue Mar 27, 2012 10:55 pm
Forum: General discussion
Topic: Linux Jedi Needed: Allocating RPi Contiguous Mem At Boot
Replies: 23
Views: 5215

Re: Linux Jedi Needed: Allocating RPi Contiguous Mem At Boot

<r>Looks like an interesting project!<br/> <br/> At least initially this seems like a data capture problem. You are correct that you have the rather nasty problem of trying to bitbang your data over GPIO pins while keeping up performance/throughput.<br/> <br/> Have you thought about SPI based memori...
by ross
Tue Dec 13, 2011 5:03 am
Forum: General discussion
Topic: Performance
Replies: 35
Views: 8913

Re: Performance

[quote]The GPU is slightly faster than the SGX543MP2 in the Ipad 2 [...] but I think the raspberry PI will use more power [/quote]

Pretty much the opposite of both of those: the GPU in the R-Pi is not as fast as the GPU in the A5 but is lower power.
by ross
Sat Dec 10, 2011 12:03 pm
Forum: General discussion
Topic: Performance
Replies: 35
Views: 8913

Re: Performance

<r>[quote]Wait a moment, comparing triangles/s, the pi is better than the iPhone 4! [/quote]<br/> This isn\'t an apples-to-apples comparison (because the screen resolutions are quite different between all three) but should give a general flavour of the relative GPU performance:<br/> <URL url="http:/...
by ross
Fri Dec 09, 2011 5:34 pm
Forum: General discussion
Topic: OpenGL Maximum Texture Size
Replies: 14
Views: 4917

Re: OpenGL Maximum Texture Size

<r>It ought to be very similar to what is reported here:<br/> <URL url="http://www.glbenchmark.com/phonedetails.jsp?benchmark=glpro11&D=Nokia+701&testgroup=gl"><LINK_TEXT text="http://www.glbenchmark.com/phonedetails ... stgroup=gl">http://www.glbenchmark.com/phonedetails.jsp?benchmark=glpro...
by ross
Sat Sep 03, 2011 2:30 pm
Forum: General discussion
Topic: DSI Screen
Replies: 11
Views: 6228

Re: DSI Screen

<t>ebay alternatives from say, 'e-go china'?<br/> Lots of fun stuff from there!<br/> <br/> The key question is "are the pins available on the final board?" - most of the panels there (including the one you linked to) need 20+ pins that would have to come out of whatever GPIOs get exposed on a header...
by ross
Sat Sep 03, 2011 11:58 am
Forum: General discussion
Topic: DSI Screen
Replies: 11
Views: 6228

Re: DSI Screen

<r>All those ebay links are for screens with CVBS inputs so will work on the R-Pi board through the composite video connector.<br/> <br/> For DSI panels you probably want to be looking for people selling replacement screens for modern phones - for example <URL url="http://www.lingosbox.com/produ.......

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