I'm developing an embedded system that uses telit gl865 modem to connect to a server using gprs.
I've noticed that the module makes a strange noise when connected. It's the same noise I used to hear in my old speaker when it was near the cellphone, and it happens when it connects to the server.
It doesn't happen with all the prototypes all the time. What could it be?
I'm afraid this will interfere with the rest of the system...