Hi all
I’m loosing my mind with this problem.
I made a script in python in a telit gps module. when running this scrypt on the development board it works just fine. But when I run it on the board that I made the scrypt only runs with the GPS antenna connect,and when I connect the GSM antenna the script just wont run.
What can be wrong?
Thank you
Not knowing the difference between circuit boards makes it hard to diagnose - did you include the active antenna support (inductor to 3.3v)?
Are all the pins connected the same way (not floating or floating)?
The application doesn’t need all of the module pins. I just connected the pins that they advise in the datasheet.
I’ve got the inductor but for the 3.8V (is the recomended power supply for the module) and the configuration for the switching power supply is respecting what is written on the datasheet.
In the osciloscope I noticed that there isn’t a drop of the value of the power supply with both antennas connected. 
I noticed you said “connect the GSM antenna” - exactly what are you connecting? GSM normally can’t do GPS - it might be creating a dead short or something.
Again, I’m not psychic, nor are the readers of this forum to my knowledge. You have some unknown script that does some unknown thing, which works in some unknown manner when a GPS antenna is connected to something, but does something else - unknown but something wrong if a GSM antenna is connected - maybe to the same thing or to something else. I can’t even begin to guess.
Also, you may not need all the pins, but many need to be left floating or connected somewhere and that is in a footnote in the datasheet where it might not be obvious.
Hi again
Let me try to explain a little better. The scrypt is very big to place it on the forum, but basicly it is a locator.
When the scrypt starts I send a short message to my phone number telling me that the system is online. If I don’t have the GSM antenna connected I recieve this message, which means that the system as already started to work. If I have the GSM antenna connected this message it isn’t sent.
Regarding the pins they are all connected like they say in the datasheet.
Hope this helps.
Thanks
There are two antennas. One GPS, and one GSM.
If I understand right:
The GPS antenna doesn’t matter.
The GSM antenna does, but attaching it actually prevents it from working.
You get messages if the GSM antenna isn’t attached.
If the above is correct, I would try checking the GSM antenna to see if it is internally shorted or disconnected.
The above is correct.
The antenna has no internal short circuit
I just bypassed the power supply and connected the module directly to a external porwer supply and the same happens, from this I conclude that it isn’t a power supply problem…
Are you add capacitors to VBATT to provide 2A consumption during registration and transmitte ? i use GM862 and no problem (i never use breakout board and only myself).