Thank you for your answer but I dont understand it. In Mega shema there are numbers just beside the chip on every pin. They look like pin numbers. To the right of that is pin name, isn't it? For example 44 SDA. What is the reason this.
Can pins 44 and 43 be used as a I2C bus?
In the text for Mega "http://arduino.cc/en/Main/ArduinoBoardMega2560" is written "TWI: 20 (SDA) and 21 (SCL). Support TWI communication using the Wire library. Note that these pins are not in the same location as the TWI pins on the Duemilanove or Diecimila. ".
Leif