Devices using the I2C standard have a master slave relationship. For more information on the differences between I2C, SPI, UART protocols, you can refer to the following resources:Similarly to other electrical components, we’ll first have to configure the GPIO pins before we get started using them! It is similar to I2C in that there is a master slave relationship between the Raspberry Pi and the devices connected to it.Typically SPI is used to send data over short distances between microcontrollers and components such as shift registers, sensors and even an SD card. According to this blog. Physical pin numbering is the most basic way to locate a pin, but many of the tutorials written for the Raspberry Pi follow a different numbering sequence.Broadcom (BCM) pin numbering (aka GPIO pin numbering) seems to be chaotic to the average user. by offering digital input/output.For GPIO pins to work, software configurations will take place, with Python libraries such as If you’re using the Raspberry Pi B+, 2, Zero, 3 or the latest Raspberry Pi 4 Model B, you’ll discover that your board have a total of 40 GPIO pins. In this tutorial, you will learn how to program Raspberry Pi GPIO using Python 3. It also includes dozens of pinouts for Raspberry Pi add-on boards, HATs and pHATs. Both of these libraries come pre-installed with the Raspbian operating system.GPIO pins have multiple names; the first most obvious reference is their “physical” location on the GPIO. So the choice of which ground pin to use is determined by personal preference, or convenience when connecting components.The 5v pins give direct access to the 5v supply coming from your mains adaptor, less power than used by the Raspberry Pi itself. 2x - 5V power pins. They work by sending data to and from the SDA connection, with the speed controlled via the SCL pin. When the Pi was designed, they used a figure of 3mA per GPIO pins in determining if the regulator could supply enough current. Appreciate your sharing this best doc. A 40-pin GPIO header is found on all current Raspberry Pi boards (unpopulated on Pi Zero and Pi Zero W). 17 pins at 3 mA each means the power regulator is only rated for 50 mA. This GPIO Pinout is designed to be both a quick and interactive reference to the Raspberry Pi GPIO pins, plus a comprehensive guide to your Raspberry Pi's GPIO interfaces. The Raspberry Pi has eight ground connections along the GPIO and each of these ground pins connects to one single ground connection. The BCM pin mapping refers to the GPIO pins that have been directly connected to the System on a Chip (SoC) of the Raspberry Pi. This can be restrictive, so you may have to get creative in certain projects. While proving to be a little more tricky to understand than standard GPIO pins, the knowledge gained from learning I2C will serve you well as you will understand how to connect higher precision sensors for use in the field.The Raspberry Pi has two I2C connections at GPIO 2 and 3 (SDA and SCL) are for I2C0 (master) and physical pins 27 and 28 are I2C pins that enable the Pi to talk to compatible HAT (Hardware Attached on Top) add on boards.SPI is another protocol for connecting compatible devices to your Raspberry Pi.
To use these pins with these protocols we need to enable the interfaces using the Raspberry Pi Configuration application found in the Raspbian OS, Preferences menu.We'll get into the specific differences between I2C, SPI and UART below, but if you're wondering which one you need to use to connect to given device, the short answer is to check the spec sheet. I2C is a quick and easy way to add many different components, such as LCD / OLED screens, temperature sensors and analog to digital converters for use with photoresistors etc to you project. Bypass these with a higher voltage and you could render your Pi inoperable.The 3v pin is there to offer a stable 3.3v supply to power components and to test LEDs.


The Raspberry Pi has two I2C connections at GPIO 2 and 3 (SDA and SCL) are for I2C0 (master) and physical pins 27 and 28 are I2C pins that enable the Pi to … The pin numbers then increase as we move down each column, with pin 1 going to pin 3, 5,7 etc until we reach pin 39.