Exploring WiFly RN-131 GSX Embedded WiFi Module

October 3rd, 2009 by Speedy Leave a reply »

I made the next step in the direction of WiFi. Some days ago I surfed the Internet for an embedded WiFi module for less money. And finally I found the WiFly GSX modules from Roving Networks. Their slogan is “Wireless for less” 😉

So I ordered some evaluation boards (about 100€/pcs) for me and two collegues who are studying with me at the NTB. Our goal is to have fun with wireless applications.

The RN-131 GSX Module is a 802.11 b/g wireless LAN Module with a lot of features – Details see datasheet.

If you already have a GSX Module you can use my LabView source below to show the UDP packets which the module sends in default configuration every 7 seconds.

The packets include

  • MAC address of AP
  • WiFi-Channel
  • RSSI (quality)
  • local TCP port
  • RTC (real time clock value)
  • NTC temperature option (if temperature sensor connected to module – otherwise sensor 7)
  • Spare sensor reading
  • ASCII time
  • Version string with date code and Device ID string

This information can be used to open a TCP connection to the module or to configure it over WiFi. The module has to be in the same subnet as your PC or MAC if you want to receive the packages.

Here are some pictures of the Module in action:

Here is the LabView (8.6) Source as LLB: wifly-monitoring-distribution



  1. ael says:

    I have this module and I trying to figure out which could be the best way to use the sensors option, what do you mean with •NTC temperature option (if temperature sensor connected to module – otherwise sensor 7) and Spare sensor reading? which could be a possible NTC configuration? I am a software developer but a newie in electronics.

    Could you help me?

  2. Speedy says:

    The WiFly-GSX has 8 analog interface inputs that can be sampled using the show q command. The
    hardware specifications on the analog input is:
    Input voltage range: 0 – 400mV.
    Resolution: 14 bits = 12uV.
    Accuracy: uncalibrated: 5%, calibrated using precision voltage or resistor measurement: 0.01%
    See the WiFly-GSX (RN-131G) data sheet for more details.

  3. ael says:

    Yes, I know the specs of the device, but I am wondering how to connect an NTC resistor taking into account the Wifly constrains, I mean:

    – 3.3 V on device power source.

    – 0-400 mV range (I want to cover the 0 to 80 or 100 ºC range).

    – Never pass over 1.2 V limit for the sensor pin, to avoid damage (ok, if 400 mV are 100 ºC i don’t have to take care about it).

    Could you give me some clues please?

  4. selim says:

    I got this module and I’m trying to build a temperature sensor monitor.Everything has done and it’s time to comunicate this module with my notebook.Firstly,can you tell me the program that communicates the module with a notebook?I read the datasheet and i should use ”teraterm pro” ,it’s written there…

  5. Jesmond Gatt says:

    Is there a way to access the analog inputs other than having to enter the command mode? I need to interface a 3 axis gyro and a 3 axis accelerometer to the module using the voltage divider bias resistors. Please help.


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