This happens because Adafruit_I2CDevice.h isn't its own standalone library. It is a critical component of the , a "helper" that Adafruit created to handle the repetitive, complex work of talking to different sensors via I2C and SPI protocols. Instead of rewriting communication code for every single sensor, they centralized it here. How to Find the "Hidden" File
For specific versions, you can find tagged releases under the Releases section of the GitHub page . How to Install the Library in Arduino IDE adafruit_i2cdevice.h zip file download
The adafruit_i2cdevice.h library is part of Adafruit's comprehensive suite of libraries designed to simplify the use of their hardware products. By downloading and installing this library, you gain the ability to: This happens because Adafruit_I2CDevice