#Ripbot264 raspberry pi how to
#Ripbot264 raspberry pi serial

It is similar to I2C in that there is a master slave relationship between the Raspberry Pi and the devices connected to it. SPI is another protocol for connecting compatible devices to your Raspberry Pi. 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.

#Ripbot264 raspberry pi how to

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. 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. They work by sending data to and from the SDA connection, with the speed controlled via the SCL pin. This means that we can talk to multiple devices on a single I2C connection as each device is unique and discoverable by the user and the computer using Linux commands such as i2cdetect.Īs mentioned earlier I2C has two connections: SDA and SCL. There can be more than one master, but each slave device requires a unique address, obtained by the manufacturer from NXP, formerly known as Philips Semiconductors. Devices using the I2C standard have a master slave relationship.

#Ripbot264 raspberry pi serial

I2C is a low speed two wire serial protocol to connect devices using the I2C standard.

These extra interfaces are activated using device tree overlays and can provide four extra SPI, I2C and UART connections. If you read the documentation that comes with a product (provided it has some), it will usually tell you which Pi pins to use.įor Raspberry Pi 4 users note that there are now many more I2C, SPI and UART pins available to you. For example, one tiny LED screen might require SPI and another might use I2C (almost nothing uses UART).

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. 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. For example GPIO3 and GPIO 4 are also SDA and SCL I2C pins used to connect devices using the I2C protocol. So for example GPIO17 is the same as BCM17.Ĭertain GPIO pins also have alternate functions that allow them to interface with different kinds of devices that use the I2C, SPI or UART protocols. Also note that BCM and GPIO pin numbering refer to the same scheme. So it is best practice to start using and learning the BCM pin numbering scheme as it will become second nature to you over time. You will see the majority of Raspberry Pi tutorials using this reference and that is because it is the officially supported pin numbering scheme from the Raspberry Pi Foundation. In essence we have direct links to the brain of our Pi to connect sensors and components for use in our projects. 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. With GPIO17, 22 and 27 following on from each other with little thought to logical numbering. 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.īroadcom (BCM) pin numbering (aka GPIO pin numbering) seems to be chaotic to the average user. And for the column starting with pin 2 it will go 4,6,8 etc until it reaches 40. You will quickly see that each pin from 1 to 39 in this column follows an odd number sequence. 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. To the right of that pin is physical pin 2 which provides 5v power. Starting at the top left of the GPIO, and by that we mean the pin nearest to where the micro SD card is inserted, we have physical pin 1 which provides 3v3 power. GPIO pins have multiple names the first most obvious reference is their “physical” location on the GPIO. Both of these libraries come pre-installed with Raspberry Pi OS. In more recent times a new library called GPIO Zero has been introduced, offering an easier entry for those new to Python and basic electronics. The most common library is RPi.GPIO and it has been used to create thousands of projects since the early days of the Raspberry Pi. Controlling a GPIO pin with Python is accomplished by first importing a library of pre-written code.