update code in order to work with python side

Signed-off-by: Cassard Mathieu <cassard.mathieu@gmail.com>
add some i2c traces

Signed-off-by: Cassard Mathieu <cassard.mathieu@gmail.com>
big i2c update (can also send data now !)

Signed-off-by: Cassard Mathieu <cassard.mathieu@gmail.com>