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 PI Therm software to interact in with your boiler or central heating system. The interface between Raspberry Pi and Central heating is a relay board. Relays are like remote control switches and are used in many applications because of their relative simplicity, long life, and proven high reliability.
The Inputs don’t have to come from a physical switch; it could be input from another computer or your security system, for example.
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