Etekcity Nutrition Scale reverse engineered imhex pattern language file

etekcity.hexpat

#pragma endian big
#pragma magic 0xFEEFC0A2

enum Type : u8 {
    SET_UNIT = 0xc0,
    SET_TARE = 0xc1,
    SET_NUTRITION = 0xc2,
    SET_AUTO_OFF = 0xc4,
    MEASUREMENT = 0xd0,
    UNIT_STATE = 0xd1,
    TARE_STATE = 0xd3,
    AUTO_OFF_STATE = 0xd5,
    ERROR_STATE = 0xe0,
    ITEM_STATE = 0xe4
};

struct t_u16_state {
    u16 state;
};

struct t_u8_state {
    u8 state;
};

struct t_bool_state {
    bool state;
};

struct t_measurement {
    bool isNegative;
    u16 weight;
    u8 unit;
    bool stable;
};

struct t_set_nutrition {
    u24 calories;
    u24 caloriesFromFat;
    u24 totalFat;
    u24 stauratedFat;
    u24 transFat;
    u24 cholesterol;
    u24 sodium;
    u24 potassium;
    u24 totalCarbs;
    u24 dietaryFiber;
    u24 sugars;
    u24 protein;
};

struct t_packet {
    char header[4];
    Type type;
    u8 length;
    
    match(type) {
        (Type::SET_UNIT | Type::SET_AUTO_OFF | Type::UNIT_STATE): t_u8_state;
        (Type::ITEM_STATE | Type::TARE_STATE | Type::ERROR_STATE): t_bool_state;
        (Type::SET_TARE): t_bool_state;
        (Type::MEASUREMENT): t_measurement payload;
        (Type::SET_NUTRITION): t_set_nutrition;
        (_): char payload[length];
    }
    
    u8 checksum;
};

t_packet test @ 0x00;