/* MEM_SIZE: the size of the heap memory. If the application will send
a lot of data that needs to be copied, this should be set high.
内存堆heap大小 */
#define MEM_SIZE (20*1024)
/* MEMP_NUM_PBUF: the number of memp struct pbufs. If the application
sends a lot of data out of ROM (or other static memory), this
should be set high.
MEMP_NUM_PBUF:memp结构的pbuf数量,如果应用从ROM或者静
态存储区发送大量数据时,这个值应该设置大一点 */
#define MEMP_NUM_PBUF 30 // default set 10