Hi,
I am working on a project where i have to send some information using SMS from a microcontroller (8051). I have succeeded in sending and receiving the SMS with a "small" problem.
I am using as modem GenPro 20e. the problem is the following: I send the following string to the modem (through the serial interface) AT+CMGS="PPPPPPP"<CR> Data to be sent: ABCDEFG <ctrl-Z> (where PPPPPP is the phone number)
the message i receive is missing the first 10 letters of the data part, so i receive the message on the phone as follows: "e sent: ABCDEFG" While testing, i realised that if i send an SMS containing less than 33 letters, the modem will not reply correctly. I have some displays on my circuit which i am using to display the string i am sending to the modem. The displays show that the string sent to the modem contains all the letters of the data part in the right order. I also saved the message in the modem's memory (using the command +CMGW) and read it on the PC using the hyperterminal it showed that the message is missing the first 10 letters :(
I went through all of the documents that come with the modem and made sure that the format of the command is correct. Also the code i am working on was previously tested using another modem and no error was detected. Also i have connected the modem to the PC and sent the same message to it and the message was received correctly.
Any help on this topic will be greatly appreciated. Thanks a lot in advance. FIF