structToNSData.m

// 構造体の例
typedef union _PacketT{
    uint8_t byte[10];

    struct {
        uint8_t stx;
        uint8_t id;
        uint16_t address;
        uint32_t data;
        uint8_t checksum;
        uint8_t etx;
    };
}PacketT;

//NSDataに変換する
-(NSData *)packetToNSData:(PacketT *) packet
{
    return [NSData dataWithBytes:packet length: sizeof(packet)];
}

//NSDataから得る
-(PacketT)nsDataToEcoMeganeData:(NSData *)data
{
    PacketT packet;
    [data getBytes:&packet length:sizeof(PacketT)];
    return packet;
}