i'm making a software with an RCM3700 module to communicate with a GPRS modem using AT commands.
I've experiencing some problems during receiving.
Sending a request for inserting PIN i'm sending:
"AT+CPIN=7159\x0d\x0a" the modem is doing what expected but i cannot parse the response.
The supposed response is: "0\r" the first time a send the command and "4\r" next times (because the pin is already given)
Unfortunately the response I receive is different every time I send the command. Sometimes "null" other times "šÃšÃ" rarely the correct answer
the last two lines are in a costate it shouldn't be a problem I think...
anyone has any advice