Sink Your Teeth into a Well Baked ‘Raspberry Pi’!
I've brought myself a 'Raspberry Pi' and I am planning to attached an external Hard-drive to it, in order for it to be used as a Stand-alone Media Server. I will use it to serve music to my Sony CMT-MX750Ni Mini Hi-Fi System. Unfortunately the Sony Hi-Fi can' access an external Hard-drive, just USB Thumb-drives. This arrangement will save me having to steam files from my PC all the time.
The 'Raspberry Pi' is the size of a Credit Card, and is as powerful as an old Pentium III PC. It’s a very capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It uses the same processor that Samsung uses in their top-end Galaxy Phones. The main difference between the 'Raspberry Pi' and the Samsung Galaxy is that the 'Raspberry Pi' only costs $35.00 US.
The Raspberry Pi measures 85.60mm x 53.98mm x 17mm, with a little overlap for the SD card and connectors which project over the edges. It weighs 45g. Model A has 256Mb RAM, one USB port and no Ethernet (network connection). Model B has 256Mb RAM, 2 USB port and an Ethernet port.
The SoC (System on Chip) is a Broadcom BCM2835, which includes an ARM1176JZF-S 700 MHz processor, with floating point, running at 700Mhz, and a Videocore 4 GPU and 256 megabytes of RAM. The GPU is capable of BluRay quality playback, using H.264 at 40MBits/s. It has a fast 3D core accessed using the supplied OpenGL ES2.0 and OpenVG libraries.
|Model A||Model B|
|Target price:||US$ 25||US$ 35|
|SoC:||Broadcom BCM2835 (CPU, GPU, DSP, and SDRAM)|
|CPU:||700 MHz ARM1176JZF-S core (ARM11 family)|
|GPU:||Broadcom VideoCore IV, OpenGL ES 2.0, MPEG-2 and VC-1 (with license), 1080p30 h.264/MPEG-4 AVC high-profile decoder and encoder|
|Memory (SDRAM):||256 MB (shared with GPU)|
|USB 2.0 ports:||1||2 (via integrated USB hub)|
|Audio outputs:||3.5 mm jack, HDMI|
|Onboard storage:||SD / MMC / SDIO card slot|
|Onboard network:||None||10/100 Ethernet (RJ45)|
|Low-level peripherals:||8 × GPIO, UART, I²C bus, SPI bus with two chip selects, +3.3 V, +5 V, ground|
|Power ratings:||300 mA (1.5 W)||700 mA (3.5 W)|
|Power source:||5 volt via MicroUSB or GPIO header|
|Size:||85.60 × 53.98 mm (3.370 × 2.125 in)|
|Weight:||45 g (1.6 oz)|
|Operating systems:||Debian GNU/Linux, Fedora, Arch Linux ARM, RISC OS|
The Raspberry Pi uses Linux kernel-based operating systems. Raspbian, a Debian-based free operating system optimised for the Raspberry Pi hardware, is the current recommended system.
The GPU hardware is accessed via a firmware image which is loaded into the GPU at boot time from the SD-card. The firmware image is known as the binary blob, while the associated Linux drivers are closed source. Application software use calls to closed source run-time libraries which in turn calls an open source driver inside the Linux kernel. The API of the kernel driver is specific for these closed libraries. Video applications use OpenMAX, 3D applications use OpenGL ES and 2D applications use OpenVG which both in turn use EGL. OpenMAX and EGL use the open source kernel driver in turn.
I'm very impressed with my 'Rasperry Pi'. The only downside that I see is the use of a mini-USB Socket to connect the 5 Volt Supply. A standard D.C. Socket makes much more since as you are recommended to use 5 Volt Supply rated at 1.5 Amps or above. After a lot of searching on and off line I found that Jaycar Australia sells the following Mains power adaptor suitable for charging apple products including iPad® retailing at AU$19.95:
- Includes 1m USB charging/sync cable
- Input: 240VAC 50Hz
- Output: 5VDC, 2.1A
Once I connected up all the leads and powered my 'Raspberry Pi' up, instantly the Linux Boot Screen appeared, and Raspbian, the Debian-based operating system. Less than 10 seconds later I was at the 'LXDE Desktop'.
I was pleasantly surprised with the 'LXDE Desktop' overall speed. The Class 4 SHDC Memory Card I'm presently using does create a 'Bottle-neck' however. I've ordered a couple of SanDisk Extreme Pro 16GB SDHC cards. One for the 'Raspberry Pi', and the other for my HD Video Camera. The Extreme Cards speed is rated up 95MB/s, compared with the Class 4's 20MB/s. I'm confident it will make a large difference to the overall Desktop Speed.
As mentioned above, the next challenge is to set up my 'Raspberry Pi' as a Media Server, to serve my music to my Sony CMT-MX750Ni Mini Hi-Fi System from an external Hard-drive.
There may even be a 'Raspberry Pi'running LEGO Mindstorms NXT Motors and Sensor using it's GPIO Outputs. A 'Raspberry Pi' NXT Shield would be great with a bit of Python thrown in……….