USR-WIFI232 wifi to serial module (HF-LPT100)

I have bought a USR-WIFI232-T module, which seems to be identical to HF-LPT100. The main chip is marked with HF so the High Flying may be the original producer. The module is only 22 x 13,5 x 6mm in size and uses external antenna connected by UFL connector. The module has a 2mm pitch pin header to connect to outside world. Manual is available here at the vendor site. I recycled a connector from an old VCR and crimped the other side of the cable with dupont connectors to be able to conveniently connect to the module.


For testing the module you need to power it with 3.3V (power supply should be capable of at least 200mA) and need  to have a serial connection. I use breadboard power supply and CP2102 USB to TTL serial converter. The breadboard power supply/regulator is slightly inconvenient as it needs an external 12V PSU. For obtaining 3.3V it could be powered by USB but for that you need a uncommon male-male usb connector which I don’t have. FTDI USB to TTL cserial onverters are said to be able to supply that amount of current at 3.3V so they may be used to both power the module and do the serial communication. However you should beware of bad power supply as that may cause unpredictable results (I also attribute some failures of different people with these and ESP8266 modules to power supply issues).


Connections are as following:

Pin 1 – GND on supply board

Pin 2 – 3.3V on supply board

Pin 5 -TXD on CP2102

Pin 6 – RXD on CP2102

GND on CP2102 – GND on supply board

Pin 9 and 10 may be used as a link indication by connecting a LED diode with a series resistor between the pin and GND connection.

When the module is first powered up it will show under wireless networks as ssid USR-WIFI232-T. You can connect to it by computer, by default the connection is unsecured. When connected the administration console / webpage can be accessed at the username and password are both “admin”. Here you can change all of the module settings. Also if you screw up the settings you can reset them by Restore function.


2014-10-21 20_45_03-Setting – Google Chrome

If you can’t access the administration console you can reset the settings by AT command. You can connect by the serial port to the module. The serial port by default works as a transparent serial console. You can check / change the baudrate at which the serial port of the module is working in the web console under Other Settings. By default the baudrate is 115200 baud and the port settings are 8-N-1. When connected to the module by WIFI you can access the serial port by TCP connection to I am using the RealTerm terminal software for both the TCP and serial connections. When connected to WIFI in one terminal and to serial port in other terminal all the characters written
in one terminal will show in the other therminal and vice-versa.

2014-10-21 21_18_41-RealTerm_ Serial Capture Program

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