Sicksaxis structa no alignment

#define SS_DATA_LEN   50
#define SS_VENDOR_ID  0x054C //Sony Corp.
#define SS_PRODUCT_ID 0x0268 //Sixaxis and DS3

struct SS_BUTTONS
{
    byte select   : 1;
    byte L3       : 1;
    byte R3       : 1;
    byte start    : 1;
    byte up       : 1;
    byte right    : 1;
    byte down     : 1;
    byte left     : 1;
    byte L2       : 1;
    byte R2       : 1;
    byte L1       : 1;
    byte R1       : 1;
    byte triangle : 1;
    byte circle   : 1;
    byte cross    : 1;
    byte square   : 1;
    byte PS       : 1;
    byte not_used : 7;
};

struct SS_ANALOG
{
    byte x;
    byte y;
};

struct SS_DPAD_SENSITIVE
{
    byte up;
    byte right;
    byte down;
    byte left;
};

struct SS_SHOULDER_SENSITIVE
{
    byte L2;
    byte R2;
    byte L1;
    byte R1;
};

struct SS_BUTTON_SENSITIVE
{
    byte triangle;
    byte circle;
    byte cross;
    byte square;
};

struct SS_MOTION
{
    u16 accX;
    u16 accY;
    u16 accZ;
    u16 Zgyro;
};

struct SS_GAMEPAD
{
    u16                            HIDdata;
    byte                           unk0;
    struct SS_BUTTONS              buttons;
    byte                           unk1;
    struct SS_ANALOG               leftAnalog;
    struct SS_ANALOG               rightAnalog;
    u32                            unk2;
    struct SS_DPAD_SENSITIVE       dpad_sens;
    struct SS_SHOULDER_SENSITIVE   shoulder_sens;
    struct SS_BUTTON_SENSITIVE     button_sens;
    u16                            unk3;
    byte                           unk4;
    byte                           status;
    byte                           power_rating;
    byte                           comm_status;
    u32                            unk5;
    u32                            unk6;
    byte                           unk7;
    struct SS_MOTION               motion;
    //byte                           padding[16];
};