Raspberry Pi Detailed Specifications

Voltages

Two 5V pins and two 3V3 pins are present on the board, as well as a number of ground pins (0V), which are unconfigurable. The remaining pins are all general purpose 3V3 pins, meaning outputs are set to 3V3 and inputs are 3V3-tolerant.

Outputs

A GPIO pin designated as an output pin can be set to high (3V3) or low (0V).

Inputs

A GPIO pin designated as an input pin can be read as high (3V3) or low (0V). This is made easier with the use of internal pull-up or pull-down resistors. Pins GPIO2 and GPIO3 have fixed pull-up resistors, but for other pins, this can be configured in software.

More

As well as simple input and output devices, the GPIO pins can be used with a variety of alternative functions, some are available on all pins, others on specific pins.

• PWM (pulse-width modulation)
  • Software PWM available on all pins
  • Hardware PWM available on GPIO12, GPIO13, GPIO18, GPIO19
• SPI
  • SPI0: MOSI (GPIO10); MISO (GPIO9); SCLK (GPIO11); CE0 (GPIO8), CE1 (GPIO7)
  • SPI1: MOSI (GPIO20); MISO (GPIO19); SCLK (GPIO21); CE0 (GPIO18); CE1 (GPIO17); CE2 (GPIO16)
• I2C
  • Data: (GPIO2); Clock (GPIO3)
  • EEPROM Data: (GPIO0); EEPROM Clock (GPIO1)
• Serial
  • TX (GPIO14); RX (GPIO15)

GPIO pinout

It's important to be aware of which pin is which. Some people use pin labels (like the RasPiO Portsplus PCB, or the printable Raspberry Leaf).

A handy reference can be accessed on the Raspberry Pi by opening a terminal window and running the command.pinout This tool is provided by the GPIO Zero Python library, which it is installed by default on the Raspbian desktop image, but not on Raspbian Lite.