I2C auto identification

Rob Dobson discusses the I2C interconnection bus (sometimes called two wire).

Ever since I attached my first I2C device to a microcontroller I’ve loved the simplicity of the I2C bus. It always seems kinda magical to have this plug-and-play ability with just two wires (maybe Dallas 1 wire is twice as magical though?).

I2C has some amazing strengths which should not be underestimated:

  • There are many, many devices from manufacturers including TI, ST and Microchip that support I2C bus standard and include: touch sensors, gas sensors, distance sensors, PIR sensors, RFID readers, Analog-to-Digital converters, accelerometers, magnetometers, gyroscopes, pressure sensors, and many more
  • Sparkfun and Adafruit have defined, respectively, Qwiic and Stemma-QT interface definitions (which are essentially the same thing and use the JST-SH 4-pin connector as standard) and provide a ton of “breakout” modules with these interfaces which makes experimentation really easy
  • I2C is simple – I know I already said that but it is really important to me so I’ve said it again!

Rob’s work is part of RaftI2C (a part of the Raft framework) and can be found on GitHub and the example application is in the examples folder of the repo. You can read the methodology in the post here.


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