User's Manual

HF-A21-SMT Embedded WiFi Module User Manual
Shanghai High-Flying Electronics Technology Co., Ltd
www.hi-flying.com
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4.2. AT+ Instruction Set Overview
User can input AT+ Instruction through hyper terminal or other serial debug terminal, also can
program the AT+ Instruction to script. User can also input “AT+H” to list all AT+ Instruction and
description to start.
Figure 40. ”AT+H” Instruction for Help
4.2.1. Instruction Syntax Format
AT+Instruction protocol is based on the instruction of ASCII command style, the description of
syntax format as follow.
 Format Description
 < >: Means the parts must be included
 [ ]: Means the optional part
 Command Message
AT+<CMD>[op][para-1,para-2,para-3,para-4…]<CR>
 AT+: Prefix of command message;
 CMD: Command string;
 [op]: Symbol of command operator,
 “=” : The command requires parameters input;
 “NULL”: Query the current command parameters setting;
 [para-n]: Parameters input for setting if required;
 <CR>：”Enter” Key, it‟s 0x0a or 0x0d in ASCII;
Notes: When input AT+Instruction, “AT+<CMD>” character will display capital letter automatic
and other parts will not change as you input.
 Response Message
+<RSP>[op] [para-1,para-2,para-3,para-4…]<CR><LF><CR><LF>
 +: Prefix of response message;
 RSP: Response string;