A big feature of the Raspberry Pi is the row of GPIO (general purpose input/output) pins. These pins are a physical interface between the Pi and the outside world. At the simplest level, you can think of them as switches that you can turn on or off (input) or that the Pi can turn on or off (output).
You can use R PiHome web interface and program the pins to interact in with the real world. Inputs don’t have to come from a physical switch; it could be input from a sensor (Pir, Light, Door, Rain….) or a signal from another computer or device, for example. The output can also do anything, from turning on an LED, control relays… If the Raspberry Pi is on a network, you can control devices that are attached to it from anywhere and those devices can send data back. Connectivity and control of physical devices over the internet is a powerful and exciting thing, and the Raspberry Pi is ideal for this.
Raspberry PI model B+/2B/3B/ZERO has 40 Pins:
- 2x 3.3V
- 2x 5V
- 8x GND
- 26x GPIO
- 1x ID_SD
- 1x ID_SC
WARNING: GPIO pins use a 3V3 logic level and are not tolerant of 5V levels.
If you short 5 V to any other pin you may permanently damage your Raspberry PI