The Raspberry Pi is a mini computer in the format of a credit card, powerful and light based on ARM microcontroller :
• It is economical.
• Very easy to use
• Free code is based on Linux with access to the software and free downloads.
• There is a large community Raspberry Pi
All components are on a circuit board about the size of a credit card : 85.60 mm x 53.98 mm x 17 mm, for a total weight of 45 g.
The embedded chip is a Broadcom BCM2835. It incorporates an ARM1176JZFS processor clocked at 700 MHz, as well as a graphics processor Videocore. The latter is able to decompress the video encoded in H.264, to a resolution Full HD (1080 p, 30, a resolution of 1920 by 1080 pixels at a speed of 30 images per second).
For 3D, OpenGL ES2.0 and OpenVG libraries are provided.
The Foundation compares the power of Pi to an Xbox 1st generation for the graphic part and a Pentium 2 clocked at 300 MHz for general use.
Two variations of the Raspberry Pi are marketed. The second is better with, because it has a 100 Mb/s Ethernet port. If the model is very oriented programming and use mode console, or even drive multimedia, model B opens up interesting prospects for use of server hosted at home.
The power consumption should be of the order of 2.5 W for the model A, against 3.5 W for model B, in the absence of devices.
In the light of these characteristics, the choice of software is a little more restrictive than in the PC world. On the one hand, because of the low computing power and on the other hand, because it is an ARM architecture with a lot of disadvantages : No auto-detection of the material, some binary opaque, a part of the specification, kept secret...
The Foundation offers two GNU/Linux distributions that are specially compiled for this computer. Fedora 13 (version 15 is expected soon) and Debian 6. If such distributions are free, it should be noted that the part bootloader and the entire GPU (OpenGL and video acceleration) will be provided in binary form and remains owner.
These system images are downloadable through torrents or direct link with http.
What you get with the Raspberry Pi.
To get costs down, the Raspberry Pi is devoid of power button. Ignition and extinction will be so in (UN) plugging the power cable that is also not delivered. Anyway, it was not enough to start an SD card not supplied is required for the boot operating system.
Need to insert a SD card on which you will have copied one of the images available for download. For convenience, the Foundation also offers the sale of pre-installed maps. The 10 000 first Raspberry Pi will be delivered naked, devoid of housing.
However, the addition of a box is planned for the next deliveries.
Raspberry Pi model A
Processor : ARM1176JZF-S (ARMv6) 700 MHz Broadcom 28351 (has a decoder Broadcam VideoCore IV(, allowing the decoding H.264 FullHD 1080 p and a VFPv2 for the calculation of the operations to comma);
RAM : 256 MB;
-2 video outputs : Composite and HDMI;
-1 output stereo audio Jack 3.5 mm (5.1 sound on the HDMI output);
-Read-write memory card unit : SDHC / MMC / SDIO.
-1 USB 2.0 port;
-Socket for Micro-USB power (consumption : 400 my + peripheral);
-Entries / additional outputs can be accessed directly on the motherboard via 3v3 55 pines : GPIO, S2C, I2C, SPI;
-API software video : OpenGL : OpenGL ES 2.0 embedded version.
-Video decoding : 1080 p 30 H.264 high-profile.
Raspberry Pi model A +
Differences with the A :
-Small : 65 mm long unlike the 86 mm
-MicroSD card reader instead of the SD reader
-40 GPIO pins
-New audio chipset
-Lower power consumption
-Price reduced to $20
Raspberry Pi Model B
Raspberry Pi Model B Rev1
-2 USB 2.0 ports instead of the single port of the model A, but on a single bus, through the SMSC LAN951257;
-1 Fast Ethernet network port (10 / 100 Mbps) via the same SMSC component.
-The LAN9512 circuit which manages both USB2 ports and the network port is connected to the CPU via a single USB2 port; Therefore, the bandwidth is shared between these three ports.
Raspberry Pi Model B Rev1 + ECN0001
-Removed the fuses protecting USB outputs
-Removal of the D14 diode, which could cause interference with devices with a CEC pin, when the Modeleraspberry PI restait connecté sans être alimenté.
Raspberry Pi Model B Rev2
-Implementation of the reset (by connecting pins 1 and 2 P6)
-Support JTAG (two GPIO pins interchangees)
-Support I2C (primary and secondary channels reversed)
-Four GPIO signals used for version identification, removal and reassignment to other roles
-SMSC + 1V8
-Two fixing holes
-Correction of the LEDs on the Platinum marking
Raspberry Pi Model B 512 MB
Socket for micro-USB power (consumption : 700 my);
The RAM passes to 512 MB (instead of 256 MB on previous models);
The model is stamped with the 4G standard in place and place of the former reference G 2, 58.
To use 512 MB of RAM, the motherboard firmware must be updated jour58.
Raspberry Pi Model B +
It is announced in July 2014.
Differences compared to the original model :
-40 GPIO pins
-4 USB 2.0 ports and better behaviour in case of overload
-reduction of consumption of 3.5 W to 3 W
-best audio circuit
-removal of the RCA Jack for the benefit of a mini-jack 4 points, including sound and video output
Raspberry Pi Model 2
February 2, 2015, the Foundation Raspberry Pi announces the release of the Raspberry Pi 2, more powerful, it is equipped with a processor Broadcom BCM2836four ARMv7 cores at 900 MHz, with 1 GB of RAM.
It has the same dimensions and connectors as the model B +.