Pic to GSM Phone connection (HSerin problems)

[Lotondo]

After a long rainy Sunday day spent in front of 16f876A I think I got where is the problem but I can not give me an answer of why this happen.
Please see code in the msg. 130+131.
If I use serial db9 pin 2 (rx) to monitor what the pic (pin 17) is sending to the phone I just see a loop of AT. Perfect no problems here.
If now I monitor what the pic (pin 18) is receiving from the phone I see:
AT
OK
According to my knowledge I should just receive OK.
After this I decided to change the line
HSerin 5000,main,[WAIT("OK")] into
HSerin 5000,main,[WAIT("AT")] and like a miracle on the screen WELL DONE and the led on.
I believe it's quite clear why with WAIT("OK") the led did not go on, after AT there is a and the OK gets lost.
I do not really understand why the phone is sending back again AT and not just OK.
If someone of you can explain me this I think I'll get the solution of my problem.
I'm waiting for yr msgs.
Thanks
Lotondo

[Ioannis]

You had to send to the mobile ATE0 (that is E and zero).

By default all phones reply what you type, so you can see on you monitor screen what you have just typed.

May be you could also try to set the phone to numeric response instead alphanumeric with ATV0. Instead of "OK" you'll get 0 and 4 for error.

Ioannis

[Lotondo]

Thanks for tips.
I tried but no success.
Well I'll try to change the phone, maybe the 7110 is not the right one.
Even in my working test (msg.135) I could see that it was unstable, sometimes it did work, sometimes not.
I can not spend too much time in these tests.
Hserout is working fine, at the moment I'll use to send out sms.
For the incoming I'll wait for a while.
Thanks

Lotondo