Raspberry Pi is a mini single-chip computer. It is developed by the Raspberry Pi Foundation in the United Kingdom along with the association of Broadcom. Raspberry Pi Zero is the smallest chipset in the Raspberry Pi series and is 40% faster than the original Raspberry Pi but nearly half of its size. Raspberry pi Zero GPIO Pinout or Pin diagram, and programming methods are explained in detail in this post.

The Raspberry Pi Zero supports mini connectors (like mini HDMI, mini USB power, and USB on-the-go port) to save more space. And the 40pin GPIO is unpopulated which provides the flexibility to use only the connections that the project requires. It consists of a 1GHz BCM2835 single-core processor, 512 MB RAM, mini-HDMI, USB On-The-Go ports, and a camera connector.

Raspberry Pi Zero GPIO Pinout in detail:

Raspberry Pi Zero GPIO Pinout

Raspberry PI Zero Power Pins:

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 zero, 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. GND pin is from where all voltages are measured and it also completes an electrical circuit.


Raspberry Pi Zero Input/Outputs pins:

The incoming voltage signal delivered by the device connected to a GPIO pin that is set as an input pin is received by this pin. The Raspberry Pi will read a voltage between 1.8V and 3.3V as HIGH, and a voltage less than 1.8V will be read as LOW.

Note: If you supply more than 3.3V to the GPIO pins, the Raspberry Pi zero will be fried.

When a GPIO pin is set as an output pin, the voltage signal is sent as either high (3.3V) or low (1.5V) (0V). When this pin is set to HIGH, the output voltage is 3.3V, and when it is set to LOW, it is 0V.

Other Important Pins on Raspberry Pi Zero:

Along with the simple function of input and output pins, the GPIO pins can also perform a variety of alternative functions. Some specific pins are:

PWM (pulse-width modulation) Pins:

  • Software PWM available on all pins
  • Hardware PWM available on these pins: GPIO12, GPIO13, GPIO18, GPIO19

SPI PINS on R-Pi Zero:

Another master-slave communication technique is SPI (Serial Peripheral Interface). The Raspberry Pi board uses it to communicate quickly with one or more auxiliary devices. The master (RPi) uses a clock (SCLK at GPIO11) to synchronise the data, and the data is delivered from the Pi to our SPI device via the MOSI (Master Out Slave In) port. When an SPI device needs to connect with the Raspberry Pi, it uses the MISO (Master In Slave Out) pin to do so.

  • SPI0: GPIO9 (MISO), GPIO10 (MOSI), GPIO11 (SCLK), GPIO8 (CE0), GPIO7 (CE1)
  • SPI1: GPIO19 (MISO), GPIO20 (MOSI), GPIO21 (SCLK), GPIO18 (CE0), GPIO17 (CE1), GPIO16 (CE2) 


I2C Pins on R-Pi Zero:

I2C is used by the Raspberry Pi board to communicate with devices that are compatible with Inter-Integrated Circuit (a low-speed two-wire serial communication protocol). This communication standard requires master-slave roles between both the devices. I2C has two connections: SDA (Serial Data) and SCL (Serial Clock). They work by sending data to and using the SDA connection, and the speed of data transfer is controlled via the SCL pin.

  • Data: (GPIO2), Clock (GPIO3)
  • EEPROM Data: (GPIO0), EEPROM Clock (GPIO1)

UART Pins on R-Pi Zero:

Serial communication or the UART (Universal Asynchronous Receiver / Transmitter) pins provide a way to communicate between two microcontrollers or the computers. TX pin is used to transmit the serial data and RX pin is used to receive serial data coming from a different serial device.

  • TX (GPIO14)
  • RX (GPIO15


  • BCM2835 single-core processor :1GHz ARM11 core
  • 512MB of LPDDR2 SDRAM
  • A micro-SD card slot
  • A mini-HDMI socket for 1080p60 video output
  • Micro-USB sockets for data and power
  • An unpopulated 40-pin GPIO header
  • An unpopulated composite video header
  • Dimension: 65mm x 30mm x 5mm
  • Composite video and reset headers
  • CSI camera connector (v1.3 only)