The Wire library is used to communicate with I2C/TWI devices. Being able to change/modify it’s buffer size is very useful for I2C/TWI device communication.

To locate the Wire.h library in the Arduino installation path and modify its buffer size, take the steps outlined below:

1. Close the Arduino IDE if open.

2. Find the file Wire.h:

   • Windows (IDE 2): C:\Users\{username}\AppData\Local\Arduino15\packages\arduino\hardware\avr\{version}\libraries\Wire\src\Wire.h
   • Windows (IDE 1.x): C:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\Wire\src\Wire.h
   • macOS: ~/Library/Arduino15/packages/arduino/hardware/avr/{version}/libraries/Wire/src/Wire.h
   • Linux: ~/.arduino15/packages/arduino/hardware/avr/{version}/libraries/Wire/src/Wire.h

3. Open the file Wire.h with a text editor.

4. Locate the line #define BUFFER_LENGTH 32 and change the number 32 to the desired value.

5. Save the changes made and close the text editor.

6. Restart the IDE.