1. 在HI2115里面，由于内存空间比较大，所以支持UDP发送指令AT+NSOST的分包
ret = sendto(socket, seq_num, data_string, length, msg_flags, (struct sockaddr *) &sock_address, sizeof(sock_address));
其中上面第2个参数，是分包的序号，从1-255
2. AT指令部分，看下面说的是6个参数可选，但是实际看代码发现，第6个参数不写的话，会报错
AT+NSOST=<socket>,<remote_addr>,<remote_port>,<length>,data>[,<sequence>] AT+NSOST=1,192.158.5.1,1024,2,AB30,1
1,2 O
AT指令的参数，第6个参数sequence就是函数里面的seq_num
<socket> Socket number returned by +NSOCR <remote addr> IP address <remote port> A number in the range 0-65535. This is the remote port that messages will be received on <length> Decimal length of data to be sent. <data> Data to be transmitted in hexstring format, or quoted string format. <sequence> Sequence of data, range 1-255.If omit, will not report data sent status. <status> The status of datagram. 0 Error 1 Sent
3. 第6个参数不写的话，会报错
cause = at_get_uint8_param(AT_PARSE_SIXTH_PARAM_POS + num_of_flags, &seq_num, true); if (cause == AT_RET_PARAM_MISSING) { seq_num = NEUL_DATA_SENT_DATA_SEQ_INVALID; } else if ((cause != AT_RET_OK) || (seq_num == NEUL_DATA_SENT_DATA_SEQ_INVALID)) { return AT_RET_SYNTAX_ERROR; }