The Raspberry Pi is a low-cost, credit-card-sized computer that plugs into a computer monitor or TV, and uses a standard keyboard and mouse that is compatible with most languages like Scratch and Python. It’s capable of doing everything you’d expect a desktop computer to do, from browsing the internet and playing high-definition video, to making spreadsheets, word-processing, and playing games.
What’s more, the Raspberry Pi has the ability to interact with the outside world and has been used in a wide array of digital maker projects, from music machines and parent detectors to weather stations and tweeting birdhouses with infra-red cameras. We want to see the Raspberry Pi being used by kids all over the world to learn to program and understand how computers work.
Below is the schematic for a Raspberry Pi 3:
Let’s look at some of the main parts in detail:
It is a 1.2GHz 64bit ARM quad-core Cortex A53 processor, with 512 KiB shared L2 cache, dual-core VideoCore IV GPU @ 400 MHz supporting OpenGL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile decode.
A powerful feature of the Raspberry Pi is the row of GPIO (general-purpose input/output) pins along the extreme right edge of the board. Like every Raspberry Pi chipset, it consists of a 40-pin GPIO. A standard interface for connecting a single-board computer or microprocessor to other devices is through General-Purpose Input/Output (GPIO) pins. GPIO pins do not have a specific function and can be customized using the software.
The board consists of two 5V pins, two 3V3 pins, and 9 ground pins (0V), which are unconfigurable.
5V: The 5v pins directly deliver the 5v supply coming from the mains adaptor. This pin can use to power up the Raspberry Pi, and it can also use to power up other 5v devices.
3.3V: The 3v pin is there to offer a stable 3.3v supply to power components and to test LEDs.
GND: Ground is commonly referred to as GND. All the voltages are measured with respect to the GND voltage.
A GPIO pin that is set as an input will allow a signal to be received by the Raspberry Pi that is sent by a device connected to this pin. A voltage between 1.8V and 3.3V will be read by the Raspberry Pi as HIGH and if the voltage is lower than 1.8V will be read as LOW.
Note: Do not connect a device with an input voltage above 3.3V to any of the GPIO pins, or else it will fry the Raspberry Pi.