"%S" is used for wide string, but we are passing a char*. Use lowercase
in this case to remove warnings like this:
libraries/AP_InertialSensor/AP_InertialSensor.cpp: In member function
'bool AP_InertialSensor::calibrate_accel(AP_InertialSensor_UserInteract*, float&, float&)':
libraries/AP_InertialSensor/AP_InertialSensor.cpp:620:61: warning:
format '%S' expects argument of type 'wchar_t*', but argument 3 has type 'const char*' [-Wformat=]
"Place vehicle %S and press any key.\n", msg);
^