Raspberry Pi: Difference between revisions

Revision as of 18:04, 23 February 2013

Revision as of 20:40, 23 February 2013

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# Support for raw [[liquid crystal display|LCD]] panels is available in hardware through the available [[Display Serial Interface|DSI]] connector from the [[Mobile Industry Processor Interface]] (MIPI) Alliance.<ref name="DSI" /> Software support is being planned.

# Supported digital video resolutions are: 640&nbsp;×&nbsp;350 [[Enhanced Graphics Adapter|EGA]]; 640&nbsp;×&nbsp;480 [[Video Graphics Array|VGA]]; 800&nbsp;×&nbsp;600 [[Super video graphics array|SVGA]]; 1024&nbsp;×&nbsp;768 [[XGA]]; 1280×720 [[720p]] [[High-definition television#High-definition display resolutions|HDTV]]; 1280&nbsp;×&nbsp;768 [[Graphic display resolutions#WXGA|WXGA]] Variant; 1280&nbsp;×&nbsp;800 [[Graphic display resolutions#WXGA|WXGA]] Variant; 1280&nbsp;×&nbsp;1024 [[SXGA]]; 1366&nbsp;×&nbsp;768 [[Graphic display resolutions#WXGA|WXGA]] Variant; 1400&nbsp;×&nbsp;1050 [[SXGA+]]; 1600&nbsp;×&nbsp;1200 [[UXGA]]; 1680&nbsp;×&nbsp;1050 [[WXGA+]]; 1920&nbsp;×&nbsp;1080 [[1080p]] [[High-definition television#High-definition display resolutions|HDTV]]; 1920&nbsp;×&nbsp;1200 [[WUXGA]].<ref name="video" /> Also to be supported are the generation of [[576i]] and [[480i]] composite video signals for [[Pal#PAL-B/G/D/K/I|PAL-BGHID]], [[PAL-M]], [[PAL-N]], [[NTSC]] and [[NTSC-J]]<ref name="composite">{{cite web|last=Ozolins |first=Jason |url=http://www.raspberrypi.org/forum/general-discussion/pictures-of-screen-displaying-example-of-rpi-composite-output?value=480i&type=1&include=2&search=1 |title=examples of Raspberry Pi composite output |publisher=Raspberrypi.org |date= |accessdate=2012-06-22}}</ref>

# Originally the on-board USB ports were designed for USB devices using one "unit load" (100 mA) of current. Devices using more than 100&nbsp;mA were incompatible with the Raspberry Pi, and for them a [[USB hub#Power|self-powered USB hub]] was required. However, due to user feedback, the RPF, at the end of August 2012, decided to remove the USB [[polyfuse]]s which largely caused this behaviour. However, the maximum current that can be delivered to a USB port on these modified boards is still limited by the capabilities of the power supply used, and the 1.1&nbsp;A main polyfuse. AlsoSpontaneous arebooting disadvantageand/or ofcrashing thecaused currentby wayhot theplugging modificationcertain isUSB donedevices iswas thatintroduced itsas noa longerresult possibleof tothis [[hot-plug]]change, USB deviceswhich directlyfurther intoreduced the PI,standards whencompliance hotpluggingof isthe necessaryRaspberry itPi's can be done in aUSB hubimplementation.<ref>{{cite web|url=http://www.raspberrypi.org/phpBB3/viewtopic.php?f=24&t=5830 |title=Design flaw? Polyfuses for USB current limiting |publisher=Raspberrypi.org |date= |accessdate=2012-06-22}}</ref>

# Newer versions of the firmware contain the option to choose between five overclock ("turbo") presets that when turned on try to get the most performance out of the SoC without impairing the lifetime of the Pi. This is done by monitoring the core temperature of the chip, and the CPU load, and dynamically adjusting clock speeds and the core voltage. So when there is a low demand on the CPU, or it is getting too hot, the performance is throttled down, but if the CPU has much to do, and the chip's temperature allows it, performance is temporarily increased, with clock speeds up to 1&nbsp;GHz, depending on the individual board, and on which of the "turbo" settings is used. The five settings are:

## "None"; 700&nbsp;MHz ARM, 250&nbsp;MHz core, 400&nbsp;MHz SDRAM, 0 overvolt,