Pi introduction
The Raspberry Pi is a very compact PC based around the type of processor used in smart phones and with capabilities comparable to those of a desktop PC of a few years ago. There are several versions of the Raspberry Pi. The Raspberry Pi 2 is shown below.
The Raspberry Pi 2 has a motherboard a bit larger then a credit card with just three chips and and a number of connectors. Indeed, it is only this large so that all the connectors can be fitted on to it.
- One chip contains the CPU and graphics processor
- One chip holds the main memory, part of which is used as the graphics memory (on the underside of the board)
- One chip handles the USB and network connectors
Connectors
There are connectors for:
- Power connector
- Micro SD memory card (the primary storage device)
- 4 USB devices
- Ethernet network cable
- Combined composite video and mono speaker connector
- HDMI to a modern TV
- Compact screen (this an unusual feature of the Pi)
- Camera (this an unusual feature of the Pi)
- 40 GPIO pins for connecting projects (this is an unusual feature of the Pi)
Uses
- Run several free versions of Linux
- Run the free Open or Libre Office suite of word processer, spreadsheet etc.
- Be a dedicated media centre to play music and video collections
- Be a web server
- Be a mail server
- Be a database server
- Build electronics projects including robots
- Run classic games using emulators
- Make a security/surveillane device to record sound and video
Limitations
- Connecting to a wireless network requires a USB wireless adaptor
- The memory can not be expanded
- The power available to the USB ports is limited. A powered hub will be need for some devices
- It will not run Microsoft Windows
- Reading CDs and DVD requires a portable USB DVD drive
- Large storage (more than an SD card can hold) requires a USB external hard drive
- Only a some versions of Linux are available for the ARM processor used by the Pi
- Some Linux applications may not be available for the ARM processor used by the Pi