Which Wire library functions requires the slave c2i device stacked on Arduino Uno? Does requestFrom(addy, quantity) or available() require the slave c2i device? thanks! :cold_sweat:
Do you mean I2C? You use the Wire library to communicate with I2C and TWI devices. If you don't have an I2C or TWI device connected to the I2C pins then the Wire library won't be of any use.
None of the functions of the Wire library "require" that you have a device to communicate with. If you address a device that is not present the communication will fail.