Arnoldo B. Canales

Raspberry Pi 3 Model B

A small and affordable computer that you can use to learn programming.

Go to the official Raspberry web site to learn more about this bord.

Figure 1: Raspberry board

Table 1

Feature Description
CPU: 1.4 GHz 64/32-bit quad-core ARM Cortex-A53
Memory: 1 GB LPDDR2 RAM at 900 MHz
Storage: MicroSDHC slot
Graphics: Broadcom VideoCore IV 300 MHz/400 MHz
O.S. Raspbian (among many others)

The Raspberry Pi is a series of small single-board computers developed in the United Kingdom by the Raspberry Pi Foundation to promote the teaching of basic computer science in schools and in developing countries. The original model became far more popular than anticipated, selling outside its target market for uses such as robotics.

According to the Raspberry Pi Foundation, over 5 million Raspberry Pis were sold by February 2015, making it the best-selling British computer. By November 2016 they had sold 11 million units, and 12.5m by March 2017, making it the third best-selling "general purpose computer". In July 2017, sales reached nearly 15 million. In March 2018, sales reached 19 million.

Figure 2: Raspberry Pi 3 B Pinout

Raspberry Pi has a 40-pin connector called GPIO header. Any of this pins can be programmed via software to be an Input or an Output.


There are two 5V pins and two 3V3 pins on the board, as well as a number of ground pins (0V). All these pins are not configurable. The remaining pins are all general purpose 3V3 pins, meaning outputs are set to 3V3 and inputs are 3V3-tolerant.


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


Any pin designated as an input pin can be read as high (3V3) or low (0V). This is accomplished with the use of internal pull-up or pull-down resistors. The exceptions are pins GPIO2 and GPIO3 who have fixed pull-up resistors.

Other functionalities

Beside using the pins as input or output, the GPIO pins can be used with a variety of alternate functions, some are available on all pins, some on specific pins.

PWM (pulse-width modulation)

Software PWM (Pulse Width Modulation) available on all pins.
Hardware PWM available on GPIO12, GPIO13, GPIO18, GPIO19

SPI - Serial Peripheral Interface bus

SPI1: MOSI (GPIO20); MISO (GPIO19); SCLK (GPIO21); CE0 (GPIO18); CE1 (GPIO17); CE2 (GPIO16)

I2C - Inter-Integrated Circuit

Data: (GPIO2); Clock (GPIO3) EEPROM Data: (GPIO0); EEPROM Clock (GPIO1)

UART - Universal Asynchronous Receiver/Transmitter - Serial Port

UART - Universal Asynchronous Receiver/Transmitter - Serial Port

TX (GPIO14); RX (GPIO15)