The Raspberry Pi is a series of small single-board computers developed to promote the teaching of basic computer science in schools and in developing countries. It is a credit card-sized, low-cost but fully functional and programmable computer with modern high-definition multimedia capabilities.
Below are the various components on the Raspberry Pi board:
Model B rev. 2 also has a pad (called P5 on the board and P6 on the schematics) of 8 pins offering access to an additional 4 GPIO connections.
Below are the various components on the Raspberry Pi board:
ARM CPU/GPU - it is a System on a Chip (SoC) which contains an ARM central processing unit (CPU) and a Videocore 4 graphics processing unit (GPU). The CPU handles taking input, doing calculations and producing output, and the GPU is used for graphics output.
GPIO - It's full form is General purpose input-output (GPIO) connector. Raspberry Pi 1 Models A+ and B+, Pi 2 Model B, Pi 3 Model B and B+, and Pi Zero and Zero W GPIO J8 contains 40-pin GPIO.
RCA - This part allows connection of analog TVs and other similar output devices.
Audio out - This is for headphones and speakers. You cannot provide audio as input using this port.
LEDs - You can use these LEDs to display the output of various projects.
USB - It is to connect USB devices such as mouse or keyboard. You can also increase number of ports using USB hubs.
HDMI - You can connect high-definition television or other compatible device to Rasberry Pi using an HDMI cable.
Power - This is a power supply. It is a 5v Micro USB power connector.
SD cardslot - This is a full-sized SD card slot. An SD card with an operating system (OS) installed is required for booting the device.
Ethernet - This connector allows for wired network access.
General purpose input-output (GPIO) connector Pin Details
Raspberry Pi 1 Models A and B have only the first 26 pins.
Raspberry Pi 1 Models A+ and B+, Pi 2 Model B, Pi 3 Model B and B+, and Pi Zero and Zero W GPIO J8 have a 40-pin pinout. They have below additional pins along with above 26 pins.
General purpose input-output (GPIO) connector Pin Details
Raspberry Pi 1 Models A and B have only the first 26 pins.
| Pin# | 2nd func. | GPIO# |
|---|---|---|
| 1 | +3.3 V | |
| 2 | +5 V | |
| 3 | SDA1 (I²C) | 2 |
| 4 | +5 V | |
| 5 | SCL1 (I²C) | 3 |
| 6 | GND | |
| 7 | GCLK | 4 |
| 8 | TXD0 (UART) | 14 |
| 9 | GND | |
| 10 | RXD0 (UART) | 15 |
| 11 | GEN0 | 17 |
| 12 | GEN1 | 18 |
| 13 | GEN2 | 27 |
| 14 | GND | |
| 15 | GEN3 | 22 |
| 16 | GEN4 | 23 |
| 17 | +3.3 V | |
| 18 | GEN5 | 24 |
| 19 | MOSI (SPI) | 10 |
| 20 | GND | |
| 21 | MISO (SPI) | 9 |
| 22 | GEN6 | 25 |
| 23 | SCLK (SPI) | 11 |
| 24 | CE0_N (SPI) | 8 |
| 25 | GND | |
| 26 | CE1_N (SPI) | 7 |
Raspberry Pi 1 Models A+ and B+, Pi 2 Model B, Pi 3 Model B and B+, and Pi Zero and Zero W GPIO J8 have a 40-pin pinout. They have below additional pins along with above 26 pins.
| Pin# | 2nd func. | GPIO# |
|---|---|---|
| 27 | ID_SD | EEPROM |
| 28 | ID_SC | EEPROM |
| 29 | N/A | 5 |
| 30 | GND | |
| 31 | N/A | 6 |
| 32 | 12 | |
| 33 | N/A | 13 |
| 34 | GND | |
| 35 | N/A | 19 |
| 36 | N/A | 16 |
| 37 | N/A | 26 |
| 38 | Digital IN | 20 |
| 39 | GND | |
| 40 | Digital OUT | 21 |
| Pin# | 2nd func. | Function |
|---|---|---|
| 1 | +5 V | N/A |
| 2 | +3.3 V | N/A |
| 3 | GPIO_GEN7 | GPIO28 |
| 4 | GPIO_GEN8 | GPIO29 |
| 5 | GPIO_GEN9 | GPIO30 |
| 6 | GPIO_GEN10 | GPIO31 |
| 7 | GND | N/A |
| 8 | GND | N/A |