Hello there! I'm new here as a registered member but not as reader. I've learned a lot here and I'm sure this is a great forum!
Well... I'm working with SIM900 and PIC32, using GPRS as a TCP Server. Everything is perfect (transparent mode), my client can connect and exchange data from one side to another. I've also added a keep alive on client side (2 in 2 minutes, using socket protocol), so (I think) GPRS provider can't drop my client when it's on and idle.
What is happening is that, suddenly, my client didn't receive the ACK from SIM900 and close the socket. But for SIM900 it's still connected! DCD pin keeps OFF and if I quit transparent mode and use +CIPSTATUS, it returns CONNECT OK. Only after a (very) long time, SIM900 notices that and enters in CLOSED status...
Is anyone facing this problem? Why is this happening?
Thanks a lot!