I2C Analog pins

Arduino Uno R3 format dictates that A4 and A5 are also used for I2C operations, so when I2C is enabled analogue inputs A4 and A5 are NOT available.

On Arduino Uno R3 this is an alternate pin function, depending on which XMC-for-Arduino boards this could be an alternate pin function, or other case as described below.

Board	Functionality	Note
XMC1100 Boot Kit	NOT supported	A4 + A5 are separate A6 + A7 are alternate pin configurations to I2C
XMC1300 Boot Kit	NOT same pin format as Arduino Uno R3	A10 + A11 are alternate pin configurations to I2C
XMC1400 Arduino Kit	Alternate pin function	Matches Arduino Uno
XMC4400 Platform 2Go	External hard wired pins	For 3V3 boards set I2C pins to tristate or open drain to use For 5V boards see Wiki board page on track cuts to enable A4 and A5 to work Level shifter on the 5V board could interfere with tristate/open drain setting
XMC4700 Relax Kit (and variants)	External hard wired pins	For 3V3 boards set I2C pins to tristate or open drain to use For 5V boards see Wiki board page on track cuts to enable A4 and A5 to work Level shifter on the 5V board could interfere with tristate/open drain setting