2 Replies Latest reply: Sep 11, 2014 11:02 AM by Harald Naumann RSS

Cell/GPS Module, Production Stage Testing


I have a device with cell/gps module and internal antennas, enclosed in a plastic + aluminum enclosure. What is the normal procedure for testing the whole device in production stage, prior to shipping. I assume making a successful phone call, sending a text message and getting gps data is too simplistic. I am looking for something more scientific, spectrum analyzer, rf power meters etc. How should one go about this ? Thanks in advance.

  • Re: Cell/GPS Module, Production Stage Testing
    Maria Lemone Novice

    you can use GT-540P (for 2G networks) or GT-540P-3GWA (for 3G networks) for a cellular based GPS device.  Here's a link to a video that shows it being used for vehicle tracking systems:  http://www.icpdas-usa.com/gt540application.php





    Maria Lemone

    ICP DAS USA, Inc.

    1-310-517-9888 ext 105


    mariaL @ icpdas-usa.com (remove spaces to send me an email)

  • Re: Cell/GPS Module, Production Stage Testing
    Harald Naumann Master

    Paul all your questions are answered after reading the IoT M2M Cookbook. I am close to 20 years in GSM / GPS and made my experience and know-how public at: M2M IoT Cookbook - How to develop a device based on wireless modules


    IoT M2M Cookbook – latest news

    The latest version of the IoT M2M Cookbook made a big jump. I bought a GSM tester and made some measurement reports public.

    Mesurement report with GSM tester

    GSM burst 33 dBm 557 us 400x298 Details out of the IoT M2M Cookbook

    GSM burst

    Such a GSM tester emulates a cellular based station. I explain in detail how to use the tester and which reports are essential in IoT M2M designs. On top I offer consultancy, local testing of your device together and sourceing an inexpensive used GSM tester.


    Supply voltage drop during 2 Watt (33 dBm)

    GSM module 220uF 100 mOhm 400x294 Details out of the IoT M2M Cookbook

    GSM module – voltage drop

    You can induce such voltage drops or overheat tests you with a GSM tester easily. Just to let you know that the power down resets are the frequently done developer mistake last 20 years. Without such a tester you have no chance to check this worst case conditions in your laboratory.

    Antenna design mistakes

    Dualband Pifa Antenna mistakes 150x150 Details out of the IoT M2M Cookbook

    GSM PIFA antenna mistake

    Several antenna design mistakes I explained in detail. Just read it, understand it and do not copy the mistakes to your design. Make it better, save money and be successful.
    I. The red arrow marked with shows the to short lenght of the ground plane
    VI. The via whole is much to big and very close to the feeding point of the antenna


    Free of charge software to match your antenna

     Details out of the IoT M2M Cookbook

    Free software for antenna tuning

    With the book you will get a ready to copy GSM antenna shape. This antenna shape is explained very detailed. All common user mistakes are simulated as well. Nevertheless the Touchstone file out of the simulation you can load to the free of charge matching software. You can research yourself what will happen by changing the value of the capacitors or inductors. You also have the freedom to run the automatic mode and generate a matching circuit based on the uploaded Touchstone file within seconds. Touchstone is also the format that you will get out of a network analyser by measuring your embedded antenna on your PCB.
    Description of Touchstone files at Wikipedia

    Radio approvels and tests

    FCC approval 400x282 Details out of the IoT M2M Cookbook

    FCC, R&TTE, PTCRB and more

    How to test an IoT M2M device and how to pass the approvels in foreign countries got an update. I tell about my concern about LTE with its bands from 700 MHz up to 3500 MHz. I mentioned problems in your design that you have to consider. Cheap equipment to test your GPS module in laboratory and in mass prodution is listed too.

    Nevertheless I will follow wishes for further content until end of this year. I will allow the sponsering of the book until end of the year as well. Any sponsor can ask for a listing in the book.

    The whole table of content of the IoT M2M Cookbook here.