Buying I2C devices

There are many I2C devices available and the price/availability can vary widely depending on your location and delivery options. Where devices are very cheap, you may find quality issues and so expect a few duds.

Some devices come with Qwiic connectors which makes them easier to plug-and-play with the Qwiic connector on your EX-CSB! or EX8874 motor shield.

In general the Adafruit devices below are high quality and well documented but that is usually reflected in the price.

• MCP23017 provides 16 pins for mixed input or output. (see details) This is good for

  • Up to 14 inputs from push-buttons, switches, sensors.
  • Up to 16 outputs to LEDs and signals (which require current limiting resistors) and relays.

• PCA9685 provides up to 16 outputs for servos and LEDs (PWM pins used for V+ include resistors) (See details)

• LTC4311 resolves electronic issues when the total of I2C wiring is greater than approximately 2m or 6ft. (See details)

• Qwiic wires make it easy to plug these devices together. (See details)

TODO

• mux
• neopixel