Notes:
Don’t worry, though, if you had your heart set on creating some real-time applications. There is another small electronics prototyping platform, called an Arduino , which contains a programmable microcontroller suitable for real-time applications. It is quite easy to use a Raspberry Pi and an Arduino board together. An Arduino can be used for the high-speed, real-time parts of the design and a Raspberry Pi can run a higher-level GUI or web application that controls the Arduino. Although the Raspberry Pi can run fast I/O applications and the Arduino can use web applications, this is not what they are best suited for. Remember: always use the right tools for the job! There is an example of communicating between an Arduino and a Raspberry Pi later in this guide.
For more information about Arduino boards, see http://www.aurduino.cc
GPIO hardware interfaces on the Raspberry Pi
There are several types of interface pins on the Raspberry Pi. They can be configured and used for lots of applications. Note that because the pins on the Raspberry Pi board are connected straight into the system on a chip (SOC), it is quite easy to damage your Raspberry Pi or SD card if you are not careful. Make sure you only use 3.3V on the pins, not 5V . For this reason, it is recommended that you use an interface board, such as the Gertboard , between the Raspberry Pi and any circuits you build.
DNC = Do Not Connect. These pins are reserved for future use.
The maximum permitted current draw from the 3.3V pin is 50mA. The maximum current draw on the 5V pin depends on your power supply – you must leave enough for the Raspberry Pi to run! Pins not listed in the table above are described by type in the sections below. Note that some pins can be configured for more than one type of interface.
Human-computer interfacing
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