pi@raspberrypi:~ $ ls -l /dev/ic*
ls: cannot access ‘/dev/ic*’: No such file or directory
pi@raspberrypi:~ $ lsmod | grep i2c
i2c_bcm2835 16384 0
i2c_bcm2708 16384 0
i2c_dev 16384 0
pi@raspberrypi:~ $ grep i2c /boot/config.txt
# dtparam=i2c_arm=on
# dtparam=i2c1=on
dtparam=i2c_arm=on
dtparam=i2c1=on
thanks for your help.