Thanks for your reply.
I connected same as schematic in Serial_Port.pdf.
Current i send AT command (AT+CMGR=1) to read sms from PIC16F877A, i receive response of SIM300 but this response is not same as specification in file "SIM300C AT.PDF" , "item 1.4" page 5, i receive AT command read (AT+CMGR=1) in top of buffer (buffer store SMS in PIC16F877A).
Detail:
- send from PIC16F877A
AT+CMGR=1\r
- wait to get response from SIM300
- content of buffer after get response
AT+CMGR=1\r\r\l+CMGR: "REC READ"\r\lSMS_content\r\l\r\lOK\r\l
specification in file SIM300C AT.PDF, response must be:
r\l+CMGR: "REC READ"\r\lSMS_content\r\l\r\lOK\r\l
I don't know why i get "AT+CMGR=1\r" string in buffer, I try with another command, the result is same. You can explain?
Note: i have a sms in Sim card.
After i read SMS, sent SMS OK, i read SMS again fail, please help me.
Thanks
duyha