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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complexity. User can save the configuration information to the flash of HF-A21-SMT, then module
will go into the appointed work mode after power up.
For a module which already finished parameters setting, it will try to connect a wireless network
and server with these parameters after power up, and serial interface is also active with pre-
configured parameters. Then all the data is transferred directly between serial interface and Wifi
interface without any interpreted.
The parameters which need to configure include:
 Wireless Network Parameters
 Wireless Network Name（SSID）
 Security Mode
 Encryption Key
 TCP/UDP Linking Parameters
 Protocol Type
 Link Type（Server or Client）
 Target Port ID Number
 Target Port IP Address
 Serial Port Parameters
 Baud Rate
 Data Bit
 Parity (Check) Bit
 Stop Bit
 Hardware Flow Control
 Work Mode Selection
 Transparent transmission
Transparent transmission demo as showing in the following figure, a HF-A21-SMT module can be
taken as a virtual serial line when UART interface working in transparent transmission mode. And
user device will realize wireless data transmition almost without any changes.
Figure 21. HF-A21-SMT Transparent Transmission Demo
2.9. Network Protocol
HF-A21-SMT module supports TCP/UDP network protocol and the port parameters can be set
via web accessing or AT+instruction set.
2.10. Parameters Configuration
HF-A21-SMT module supports two methods to configuration parameters: Web Accessing and
AT+instruction set.
Web accessing means users can configure parameters through Web browser. When HF-A21-
SMT module connected to wireless network, parameters configuration is done on a PC