I2C
Contributors:
SFUptownMaker
SFUptownMaker 
Resources and Going Further
I2C is a relatively complex interface, and there are many resources out there to help you deal with it. Below are some of the more informative ones.
- Wikipedia Article on I2C - Not great, but not a terrible place to start.
- Standards Doc - Phillips Semiconductor became NXP a few years back; this is the official standards doc for I2C.
- I2C primer - The official primer on I2C and related technologies.
- Linux Tools for I2C - A nice set of tools for working with I2C and related buses in embedded Linux environments, like pcDuino or Raspberry Pi.
- Open Source Hardware Association: A Resolution to Redefine SPI Signal Names
- Qwiic Connect System
To use I2C over long distances, check out the dedicated PCA9615 differential I2C bus extender.
Qwiic Differential I2C Bus Extender (PCA9615) Hookup Guide
Learn how to extend the range of your I2C communication bus with the Qwiic differential I2C bus extender (PCA9615 ) breakout board.
Or check out our SPI and I2C tutorial with a Raspberry Pi.
Raspberry Pi SPI and I2C Tutorial
Learn how to use serial I2C and SPI buses on your Raspberry Pi using the wiringPi I/O library for C/C++ and spidev/smbus for Python.
Need some inspiration for your next project? Check out some of these related tutorials:
SparkFun Humidity Sensor Breakout - SHTC3 (Qwiic) Hookup Guide
A Hookup Guide to get started using the SHTC3 breakout.
SparkFun Qwiic Shield for Teensy Hookup Guide
A short guide for assembling and using the SparkFun Qwiic Shield for Teensy and Qwiic Shield for Teensy Extended.
Air Quality Sensor - SGP40 (Qwiic) Hookup Guide
Get started measuring indoor air quality with the SparkFun Air Quality Sensor - SGP40 (Qwiic) Hookup Guide.
Air Velocity Sensor Breakout - FS3000 Hookup Guide
Get started with the Air Velocity Sensor Breakout - FS3000!
Looking for more inspiration? Check out some of these blog posts for ideas: