This method reads the value from the specified port on the robot.
The ports are exposed on the robot as TinkerKit connectors.
The board has a 10-bit analog to digital converter.
This means that it will map input voltages between 0 and 5 volts into integer values between 0 and 1023.
The parameter port can be one of the following:
*TK0 to TK7 (found on the Control Board)
*TKD0 to TKD5 (found on the Control Board)
*B_TK1 to B_TK4 (found on the motor Board)
If the input port is not connected to anything, the value returned by Robot.analogRead() will fluctuate based on a number of factors (e.g. the values of the other analog inputs, how close your hand is to the board, etc.).
Serial.println(Robot.analogRead(TK0)); //Print the value on port TK0