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by lb
Tue Mar 01, 2016 6:01 pm
Forum: Advanced users
Topic: Raspberry Pi 3 - Bluetooth PL011 UART (9bit on mini-UART)?
Replies: 22
Views: 13419

Re: Raspberry Pi 3 - Bluetooth PL011 UART (9bit on mini-UART

Ignoring the trolling, it would be interesting to know why the PL011 UART is used for the BT, and if it's actually possible to use the Mini UART with BT (with lower performance or whatever).
by lb
Tue Mar 01, 2016 4:54 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

As described in https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=138120 Bluetooth uses the PL011 UART by default, so only the Mini UART is free for use. However, it unfortunately has various restrictions. Does Bluetooth need to use the PL011 UART for some special reason, or can we switch it t...
by lb
Tue Mar 01, 2016 4:38 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

Does the WiFi chipset support channel 13 (in regions where it is allowed)? I can't find any clear info on this. The Linux CRDA framework controls whether you can tune to channels >11. Set this via iw (e.g. iw reg set US). Sure, but some hardware isn't physically capable of operating at channels > 1...
by lb
Tue Mar 01, 2016 4:32 pm
Forum: Advanced users
Topic: Raspberry Pi 3 - Bluetooth PL011 UART (9bit on mini-UART)?
Replies: 22
Views: 13419

Re: Raspberry Pi 3 - Bluetooth PL011 UART (9bit on mini-UART

Yes, this is a *serious* shortcoming! I may need parity for some applications, too. Is the GPIO configuration flexible enough to swap around the UARTs? Bluetooth doesn't really need all that much bandwidth, right? Edit: looking at the possible pin configurations and the Pi 3 DT configuration, it loo...
by lb
Tue Mar 01, 2016 1:08 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

Does the WiFi chipset support channel 13 (in regions where it is allowed)? I can't find any clear info on this.
by lb
Mon Feb 29, 2016 6:51 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

I guess the Pi 3 should be able to decode 1080p30 MPEG-2 or VC-1 in software, so codec licenses aren't really needed anymore?
by lb
Mon Feb 29, 2016 2:47 pm
Forum: General discussion
Topic: I feel like betrayed
Replies: 126
Views: 11915

Re: I feel like betrayed

Well, the Pi 3 clearly is a compromise. It's a good compromise, though. It's still 99% backwards compatible in hardware and software to the first Pi released 4 years ago, despite countless feature additions and improvements! That's a pretty amazing feat. Others sell SBCs, Raspberry Pi sells a platfo...
by lb
Mon Feb 29, 2016 2:23 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

1g of ram, 64bit cpu, what is point? more ram eating? ARMv8 brings a bunch of improvements including double the number of general purpose registers, double-wide registers, double the number of NEON registers, and an improved instruction set (including integer divide). The extra registers alone usua...
by lb
Mon Feb 29, 2016 11:37 am
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

I think the question whether the WiFi hardware can do this is rather moot (also, is there any non-ancient WiFi hardware that actually lacks Soft AP capabilities?). The question is: does it *actually work in practice*? Because the best hardware is useless when the driver is lacking the feature, or wh...
by lb
Mon Feb 29, 2016 10:20 am
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

The Broadcom SDHOST (which doesn't do UHS modes, but can be overclocked) now talks to the SD card. Just to pad this out a little, it can be overclocked by up to 100%, ie, a doubling of the standard 50MHz clock speed. 42MB/s transfers via the card slot are nothing out of the ordinary on the old hard...
by lb
Mon Feb 29, 2016 10:19 am
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

Regarding an ARMv8 variant of Raspbian, why not use AArch32, the 32 bit variant of the ARMv8 architecture? It has all the advantages of the new instruction set, but still uses 32 bit pointers. Makes sense on a device with limited memory like the Pi, if you ask me. Since when has 1GB of RAM been 'li...
by lb
Mon Feb 29, 2016 10:13 am
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

On previous Pi models, The SD slot was unable to use UHS transfers modes due to lack of 1.8V I/O voltage capability. Has this changed? The SoC can do UHS in theory. As CPU speed increases even more, I/O starts to become a serious bottleneck, and UHS would certainly help a bit here. The Arasan eMMC ...
by lb
Mon Feb 29, 2016 10:02 am
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 177653

Re: The Raspberry Pi 3 Model B Q&A thread

On previous Pi models, The SD slot was unable to use UHS transfers modes due to lack of 1.8V I/O voltage capability. Has this changed? The SoC can do UHS in theory. As CPU speed increases even more, I/O starts to become a serious bottleneck, and UHS would certainly help a bit here. Regarding an ARMv...
by lb
Tue Dec 08, 2015 9:21 pm
Forum: General discussion
Topic: Meet Raspberry Pi Zero: the $5 computer
Replies: 539
Views: 79477

Re: Meet Raspberry Pi Zero: the $5 computer

The pricing of vendor's in Germany (and probably elsewhere) is a real problem right now. (read: they are ripping off customers.) The cheapest Pi Zero in Germany sells for no less than 14.50 EUR. Some offers are upwards of 20 EUR and don't even include any HDMI/USB adapters. I hope the availability i...
by lb
Tue Jun 03, 2014 3:27 pm
Forum: Advanced users
Topic: Bit-banging SPI
Replies: 7
Views: 2548

Re: Bit-banging SPI

Strange, hardware SPI (spidev) should be pretty fast. It's pretty capable and can run at high clocks. Did you set up an appropriate clock for hardware SPI?
by lb
Fri May 30, 2014 12:12 pm
Forum: Advanced users
Topic: how to detect a new joining device by PI?
Replies: 13
Views: 2795

Re: how to detect a new joining device by PI?

IPv6 multicast works much more reliably than IPv4 broadcasts. You can enable IPv6 on your Pi and execute "ping6 ff02::1%eth0", all IPv6-capable devices on the network should answer.

Another option is to listen for zeroconf/mdns packets, but that of course also needs to be supported by the devices.
by lb
Thu May 30, 2013 10:25 pm
Forum: OpenGLES
Topic: GPU memory usage of RGB textures
Replies: 1
Views: 1811

Re: GPU memory usage of RGB textures

GPUs typically don't support RGB formats in hardware, due to the horrible alignment issues it poses. It's quite normal. If you can, use ETC1 texture compression. You'll lose some quality, but at just 4 bits per pixel, the data size will be very small.
by lb
Fri May 17, 2013 2:15 pm
Forum: OpenGLES
Topic: glAttachShader with multiple shader methods not compiling?
Replies: 1
Views: 1996

Re: glAttachShader with multiple shader methods not compilin

I have a very simple setup of using multiple shaders to implement multi mode. basically i select the fragment shader chunks at runtime and call glAttachShader (which as far as i know concats them together). Then in my "main" fragment shader i declare the methods from the other chunks, and use them ...
by lb
Mon Apr 22, 2013 1:11 pm
Forum: OpenGLES
Topic: Copy texture to texture
Replies: 2
Views: 1957

Re: Copy texture to texture

I'm not sure if it is the most efficient way, but this certainly works and should be much faster than going through host memory: 1. Create an FBO and attach destination texture as color buffer 2. Render into the FBO with suitable shader and source texture You might be able to combine this with the m...
by lb
Wed Apr 17, 2013 12:05 am
Forum: Graphics programming
Topic: dispmanx: disable framebuffer layer
Replies: 0
Views: 1361

dispmanx: disable framebuffer layer

The Linux framebuffer is a regular dispmanx layer. Is there some way to (temporarily) disable compositing of the framebuffer layer while an application runs? I've seen people add an opaque black layer on top of the framebuffer layer to mask it, but that seems counterintuitive. The framebuffer layer ...
by lb
Tue Apr 16, 2013 11:56 pm
Forum: Graphics programming
Topic: OpenGL ES 3.0
Replies: 14
Views: 10514

Re: OpenGL ES 3.0

That's usually right, but the unusual architecture of the VideoCore GPU is quite flexible, probably enough for at least a partial implementation of GLES3. That said, I would already love to have some of the more common GLES2 extension, e.g. GL_OES_element_index_uint. The lack of this extension is ba...
by lb
Fri Apr 05, 2013 12:23 pm
Forum: Graphics programming
Topic: OpenGL ES 3.0
Replies: 14
Views: 10514

OpenGL ES 3.0

Quick question, is there any chance for OpenGL ES 3.0 support on the Pi? Dom? :)
by lb
Wed Dec 12, 2012 12:51 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Secondary SD/MMC interface
Replies: 23
Views: 12411

Re: Secondary SD/MMC interface

The drivers are all part of the kernel. You just need to patch the hardware configuration in arch/arm/mach-bcm2708/bcm2708.c. Sorry, I can't find the patch now, but it's quite straight-forward.
by lb
Wed Dec 12, 2012 12:40 pm
Forum: General discussion
Topic: ext3/4 and SD-card wear leveling
Replies: 133
Views: 47031

Re: ext3/4 and SD-card wear leveling

Yeah, but that's pretty obvious. Static wear levelling is hard, dynamic wear levelling is easy and you almost get it for free when implementing the block mapping. Still, the SD protocol (as opposed to the USB mass storage protocol) has block erase commands, and the controller might take advantage of...
by lb
Wed Nov 07, 2012 2:00 pm
Forum: General discussion
Topic: Simon's accelerated X development thread
Replies: 405
Views: 124498

Re: Simon's accelerated X development thread

Cortex-A8 has NEON SIMD, though, which greatly speeds up most important operations (copy, composite). It's possible to achieve 4-5x speedups of typical alpha blending operations (compared to scalar code), as long as memory bandwidth allows it.

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