Raspberry Pi FAQs
Table of Contents:
The Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. It is a capable little computer which can be used in electronics projects, and for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. We want to see it being used by kids all over the world to learn programming.
The Raspberry Pi Foundation is a charity, so you can’t buy shares in the company. If you want to support us, we would love you to buy a Raspberry Pi.
You can buy a Raspberry Pi directly from our website. You can buy from our main distributors, Premier Farnell/Element 14 and RS Components/Allied Electronics. Both distributors sell all over the world. In mainland China, Taiwan, Hong Kong and Macau you can also buy directly through Egoman Technology Corp. There are also many resellers.
The Model A costs $25 and the Model B and the Model B+ cost $35, plus local taxes and shipping/handling fees.
You get the Raspberry Pi board itself. A power supply or SD cards are not included, but can be purchased at the same time from most places that sell the Raspberry Pi. You can also purchase preloaded SD cards too; we recommend buying these from us or our licensed distributors rather than from third parties on eBay, as the software is being updated all the time.
The components we buy are priced in dollars, and we negotiate manufacturing in dollars. Because currency markets are so volatile, we price the final board in dollars too so we don’t have to keep changing the price.
Not yet. We may implement a program of this sort one day, but we’ve come to appreciate that the scale of a program like this may be something our small team isn’t equipped to handle without taking on extra staff. You can also just buy an extra Pi to donate to the person or organisation of your choice.
We have an exclusive distribution arrangement with RS and Farnell. Resellers that chose to do so are buying the Raspberry Pi in bulk from them (which reduces shipping costs to nearly nothing) and selling on. You do not need any special license to resell, and they are very happy to sell on to resellers. Unfortunately, because of the way the pricing model (and the fact that we are a charity) works, you will have to buy in very large bulk before you will qualify for any bulk discount – what most resellers are doing is using it as a way to sell high-margin peripherals and so on.
The default username for Raspbian is “pi” (without any quote marks) and the default password is “raspberry” (again, do not include the quote marks). If that does not work, check the information about your specific distro on the downloads page.
To protect your information, Linux does not display anything when typing in passwords in the bash prompt or the terminal. As long as you were able to see the username being typed in, your keyboard is working correctly.
The Model A has 256MB RAM, one USB port and no Ethernet (network connection). The Model B has 512MB RAM, 2 USB ports and an Ethernet port. The Model B+ shares the same specs as the Model B, but comes with 4 USB ports. See the products pages for more details.
The Model A has one USB port, the Model B has two, and the Model B+ has four, that can be used to connect most USB 2.0 devices. Additional USB devices such as mice, keyboards, network adapters and external storage will all connect via a USB hub.
There is no on/off switch!
To switch on: just plug it in.
To switch off: If you are in the graphical environment, either exit to the bash prompt or open the terminal. From the bash prompt or terminal shut down the Raspberry Pi by entering “sudo halt -h” (without the quote marks) . Wait until all the LEDs except the power LED are off, then wait an additional second to make sure the SD card can finish its wear leveling tasks and write actions. You can now safely unplug the Raspberry Pi. Failure to properly shut the Raspberry Pi may corrupt your SD card, and you will have to re-image it.
NOOBS stands for New Out of Box Software. It is our recommended installation method. It allows you to install the distro of your choice even if you have little to no computing or Linux experience. You can learn more about NOOBS here.
As of the Febraury of 2015, the second generation of the Raspberry Pi, has been released, initially with a Model B version. Beyond this revision, which upgraded the main processor on the board to a quad core and doubled the RAM while maintaining full backwards compatibility with the original Raspberry Pi, there are no immediate plans for the next model; a new model may be released in 2-3 years, but this is not a firm schedule. We concentrate our engineering effort on making the software that runs on the Raspberry Pi faster and better all the time – which is why you should always be running the most recent firmware.
The Raspberry Pi measures 85.60mm x 56mm x 21mm (or roughly 3.37″ x 2.21″ x 0.83″), with a little overlap for the SD card and connectors which project over the edges. It weighs 45g.
All available documentation is in our documentation repository.
The SoC is a Broadcom BCM2835. This contains an ARM1176JZFS, with floating point, running at 700Mhz; and a Videocore 4 GPU. 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.
SoC, or System on a Chip, is a method of placing all necessary electronics for running a computer on a single chip. Instead of having an individual chip for the CPU, GPU, USB controller, RAM, Northbridge, Southbridge, etc., everything is compressed down into one tidy package.
Cost and performance.
All the files necessary for booting are installed in a FAT32 partition of the SD card. The Raspberry Pi has to have an SD card installed to boot from, but a USB HD can “take over” after the initial boot. You cannot boot without an SD card.
No. It would be too expensive for us to provide kits alongside finished boards, which would mean introducing another step in manufacturing; and a kit would be impossible to hand solder. We use special equipment (robots!) to solder on the BGA package and other tiny components.
The GPU provides Open GL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile encode and decode.
The GPU is capable of 1Gpixel/s, 1.5Gtexel/s or 24 GFLOPs of general purpose compute and features a bunch of texture filtering and DMA infrastructure.
This means that graphics capabilities are roughly equivalent to the original Xbox’s level of performance. Overall real world performance is something like a 300MHz Pentium 2, only with much, much swankier graphics.
The Raspberry Pi operates at 700 MHz by default. Most devices will run happily at 800MHz. In the latest Raspbian distro (you can download the Raspbian image directly or install it via the NOOBs installer, both available on our downloads page) there is an option to change the overclocking options on first boot and any time afterwards by running “sudo raspi-config” without voiding your warranty. It should be noted that these are experimental settings and not every board will be able to run stably at the highest setting. If you experience issues, try reducing the overclocking settings until stability is restored.
No. The chip used in the Raspberry Pi is equivalent to a chip used in a cellphone, and does not become hot enough to need any special cooling. Of course, if you just like the look of a heatsink, you will not hurt anything by placing an appropriately sized heatsink on it.
The Raspberry Pi has 26 dedicated GPIO pins, including a UART, an i2c bus, a SPI bus with two chip selects, i2s audio, 3v3, 5v, and ground.
The maximum number of GPIOs can theoretically be indefinitely expanded by making use of the i2c or SPI bus.
The expectation is that non-network connected units will have their clocks updated manually at startup. Adding an RTC is surprisingly expensive, once you have factored in batteries, area and componentry, and would have pushed us above our target price. You can add one yourself using the GPIO pins if you’re after an interesting electronics project.
No. The RAM is a Package on Package (POP) on top of the SoC, so it is not removable or swappable, and 512 MB is the maximum RAM the Raspberry Pi can support since there are no manufacturers making larger-capacity compatible devices.
7. Why doesn’t the Raspberry Pi include <insert name> piece of hardware or <insert name> sort of port?
Our main function is a charitable one – we are trying to build the cheapest possible computer that provides a certain basic level of functionality, and keeping the price low means we’ve had to make hard decisions about what hardware and interfaces to include.
Yes. We have conducted extensive virtual simulations. No Raspberry Pis were harmed in the testing.
The Camera Board is a small PCB that connects to the CSI-2 camera port on the Raspberry Pi using a short ribbon cable. It provides connectivity for a camera capable of capturing still images or video recordings. The camera connects to the Image System Pipeline (ISP) in the Raspberry Pi’s SoC, where the incoming camera data is processed and eventually converted to an image or video on the SD card (or other storage). You can read more about the camera board here.
The camera module is an Omnivision 5647. It comparable to cameras used in mobile phones.
The camera module is capable of up taking photos up to 5 megapixels (5MP) (2592×1944 pixels) and can record video at resolutions up to 1080p30 (1920x1080x30fps).
The camera module supports raw capturing (Bayer data direct from the sensor) or encoding as JPEG, PNG, GIF and BMP, uncompressed YUV, or uncompressed RGB photos. It can record video as H.264, baseline, main or high-profile formats.
There are three command line applications provided for stills, video, and stills output uncompressed. These applications provide the typical features you might find on a compact cameras, e.g. Set image size, compression quality, exposure mode, ISO. See the documentation for more details.
Yes. We have reports of people using cables up to 4 meters and still receiving acceptable images, though your mileage may vary.
No, this is the only camera module that is compatible with the Raspberry Pi. There are currently no plans to release a higher-resolution sensor.
The camera board requires 250mA to operate. Make sure you ensure your power supply can provide enough power for the camera module as well as the Raspberry Pi, and any peripherials directly attached to the Raspberry Pi.
At this time, there is no official case, however the educational boxed release planned for 2014 will have a case by default. There are lots of homebrew case discussions on the forum as well as several third party cases available. We suggest stopping by the cases sub-forum and reading some of the threads about cases you can purchase or build yourself.
No, since the corners are not rounded and the Ethernet/USB/SD card slot stick out just a little bit, the Raspberry Pi will not fit in an Altoids tin. If, however you make some heavy modifications to the Altoids tin to let the corners and the Ethernet/USB/SD card stick out, you may be able to squeeze one in. Of course, at that point you are probably better off hammering the top of an Altoids tin into the top of an enclosure the Raspberry Pi can actually fit in.
There is composite and HDMI out on the board, so you can hook it up to an old analogue TV through the composite or through a composite to scart connector, to a digital TV or to a DVI monitor (using a cheap, passive HDMI->DVI cable for the DVI).
For the Model B+, the RCA composite jack has been replaced with a 3.5mm jack that combines audio and video onto one jack. You’ll need a 3.5mm to 3 RCA adapter cable to connect it to an older TV. There are many different types of this cable out there, but you want to purchase one that is compatible either with the iPod Video or Zune (the iPod will have the left and right audio channels reversed, but the version of Raspbian included with NOOBs can swap this for you)
There is no VGA support, but active adapters are available. Passive HDMI->VGA cables will not work with the Raspberry Pi. When purchasing an active VGA adapter, make sure it comes with an external power supply. HDMI->VGA adapters without an external power supply often fail to work.
Yes, the HDMI port on the Raspberry Pi supports the CEC Standard. CEC may be called something differently by your TV’s manufacturer; check the Wikipedia entry on CEC for more information on the CEC standard and the different names it is called.
The chip we use supports HDMI and composite outputs but does not support VGA. VGA is considered to be an end-of-life technology, so supporting it doesn’t fit with our plans at the moment.
Several third-party web stores offer touchscreens for the Raspberry Pi, and we will be releasing an official touchscreen later in 2014.
The Raspberry Pi can encode (record) and decode (play) h.264 (mp4/mkv) out of the box. There are also two additional codecs you can purchase through the Swag Store that enable you to decode MPEG-2, a very popular and widely used format to encode DVDs, video camera recordings, TV and many others, and VC-1, a Microsoft format found in Blu-ray discs, Windows Media, Slingbox, and HD-DVDs.
There is a standard 3.5mm jack for audio out to an amplifier. You can add any supported USB microphone for audio in, or using the I2S interface you can add a codec for additional audio I/O.
The device is powered by 5v micro USB. Exactly how much current (mA) the Raspberry Pi requires is dependent on what you hook up to it. We have found that purchasing a 1.2A (1200mA) power supply from a reputable retailer will provide you with ample power to run your Raspberry Pi for most applications, though you may want to get a 2.5A (2500mA) if you want to use all 4 USB ports on the Model B without using an external powered USB hub.
Typically, the model B uses between 700-1000mA depending on what peripherals are connected, the Model B+ has slightly more efficient power circuits as well as more available USB ports and can use between 600-2000mA, and the model A can use as little as 500mA with no peripherals attached. The maximum power the Raspberry Pi Model A and B can use is 1 Amp, so if you need to connect a USB device that will take the power requirements of the Raspberry Pi above 1 Amp then you must connect it to an externally powered USB hub. Alternatively, the maximum power the Model B+ can use is 2 Amps before needing to connect devices to an externally powered USB hub.
The power requirements of the Raspberry Pi increase as you make use of the various interfaces on the Raspberry Pi. The GPIO pins can draw 50mA safely (that is 50mA distributed across all the pins! An individual GPIO pin can only safely draw 16mA), the HDMI port uses 50mA, the camera module requires 250mA, and keyboards and mice can take as little as 100mA or over 1000mA! Check the power rating of the devices you plan to connect to the Pi and purchase a power supply accordingly. If you’re not sure, buy a powered hub.
It depends on the hub. Some hubs comply with the USB 2.0 Standard and only provide 500mA per port, which may not be enough to power your Raspberry Pi. Other hubs view the USB standards more like guidelines, and will provide as much power as you want out each port. Please also be aware that some hubs have been known to “backfeed” the Raspberry Pi. This means that the hubs will power the Raspberry Pi through its USB cable input cable, without the need for a separate micro-USB power cable, and bypass the voltage protection. If you are using a hub that “backfeeds” to the Raspberry Pi and the hub experiences a power surge, your Raspberry Pi could potentially be damaged. The additional information column provides details as to whether the Raspberry Pi can be powered directly off the hub and if the hub “backfeeds” power to the Raspberry Pi.
Running the Raspberry Pi directly off batteries requires special care and can result in damaging or destroying your Raspberry Pi. If you consider yourself an advanced user, have a go.
For example: 4xAA rechargeable batteries would provide 4.8v on a full charge. 4.8v would technically be just within the range of tolerance for the Raspberry Pi, but the system would quickly become unstable as the batteries lost their full charge.
Conversely, using 4xAA Alkaline (non-rechargeable) batteries will result in 6v. 6v is outside the acceptable tolerance range and will potentially damage or in the worst case scenario destroy your Raspberry Pi.
It is possible to provide a steady 5v from batteries by using a buck and/or boost circuit, or by using a charger pack which is specifically designed to output a steady 5v from a couple of batteries (these devices are typically marketed as cell phone emergency battery chargers).
Not in the base device. There are adapters that would split the voltage off the Ethernet line before connecting to the Pi, but they are relatively expensive.
There are several official distributions (distros) available on our downloads page. New users will find the NOOBs installer the easiest to work with, as it walks you through the download and installation of a specific distro. The recommended distro is Raspbian, which is specially designed for the Raspberry Pi and which our engineers are always optimising; but it is a straightforward process to replace the root partition on the SD card with another ARM Linux distro, so we encourage you to try out several distros to see which one you like the most. The OS is stored on the SD card.
The Raspberry Pi Foundation recommends Python as a language for learners.
Any language which will compile for ARMv6 can be used with the Raspberry Pi, though; so you are not limited to using Python. C, C++, Java, Scratch, and Ruby all come installed by default on the Raspberry Pi.
Wine Is Not an Emulator. Some people have put Windows 3.1 on the Raspberry Pi inside an x86 CPU emulator in order to use specific applications, but trying to use a version of Windows even as recent as Windows 98 can take hours to boot into, and may take several more hours to update your cursor every time you try to move it. We don’t recommend it!
No. Even if Microsoft decided to devote all its resources to getting Windows 8 on the Pi it would not work. The Raspberry Pi lacks the minimum memory and CPU requirements, it runs on an version of the ARM processor that is not supported by Windows 8, it lacks the appropriate axis sensors… the list goes on and on. The Pi will not run Windows 8.
A complete list of the officially supported distros can be found on our downloads page.
No. While a version of Android can be found in the forum, it is not stable enough for everyday use. There are no plans to continue working on it, as Android does not provide any enhancement to educational purposes that are not already fulfilled more readily with existing software – we see it as a platform for consumption, not creation.
In general, you need to look to see whether the program you want can be compiled for the ARMv6 architecture. In most cases the answer will be yes. Specific programs are discussed on our forum, so you might want to look there for an answer. Ultimately, nothing beats grabbing a Raspberry Pi and finding out the answer through direct testing!
Whether you want to use the NOOBS installer or a standalone distro image, the minimum size SD card we recommend using is 6GB, but we’d recommend 8GB for safety. This will give you the free space you need to install additional packages or make programs of your own.
We have tried cards up to 32GB, and most cards seem to work OK. You can also attach a USB stick or USB hard drive for storage.
You can restore the device by reflashing the SD card.
The Model B and Model B+ version of the device have built in 10/100 wired Ethernet. There is no Ethernet on the Model A version.
No model of the Raspberry Pi has built in Wi-Fi, but all three can support a USB Wi-Fi dongle.
Unlikely. The SoC does not support native Wi-Fi, and adding an additional built in Wi-Fi chip would greatly increase the cost of the Raspberry Pi.
The Ethernet is attached via the USB 2.0 bus, so the upstream bandwidth would not support Gigabit.
No. However, it’s such a low power device that we expect it to be left on much of the time!
Use a hub to increase the number of ports or purchase the Model B+ which comes with four USB ports. Some keyboards have hubs built in which would work well. It is highly recommended that you use a powered hub.
There are many books about the Raspberry Pi available. For kids, we particularly recommend Adventures in Raspberry Pi by Carrie Anne Philbin, who works with us at the Foundation.
Check out our resources for free educational materials, which we’re always adding to. You’ll find complete schemes of work linked to the UK curriculum, as well as resources for independent and informal learning.
I still have more questions!
Read the sticky subjects in the Beginners subform and check the help pages for more information. If the answer is not there, ask it in the forums, where there are lots of helpful Raspberry Pi owners, users and fans who will be more than happy to help you out.
Source: FAQs | Raspberry Pi