My SIM300CZ doesn't answer (with PIC 16F917)

[Matthieu66]

sim300cz datasheet

Hello everybody!

I'm trying to send AT commands with my PIC 16F917 to a SIM300CZ modem. The program in the PIC worked with another modem (Siemens TC35).

My SIM300CZ powered on well (VDD = 4V for the PIC and the modem). So I adapt the level of voltages in order to have 3V on a high level of the RXD pin of the modem (the max in the datasheet is 3,3V).

The TXD of the modem is connected to the Rx of the PIC and the RXD of the modem is connected to the Tx of the PIC.
I send and receive datas only with TXD abd RXD (I don't use DCD, DTR, RTS, CTS and RI). So, I don't exactly know where should be connected these unused pins? For the moment, I put RTS to the ground and the others aren't connected.

My baudrate is 9600bps, which is the default baudrate for the SIM300CZ.

Can anyone help me please?

 

[abbas.khodaeian]

Hi dear, i have same project. i need to connect same modem to the pic 16f877.
i havn't any datasheet of this modem, but i can help you. because several time ago, i can connect mobile phone with PIC16f628 and it work very well. and i can send and receive sms with the phone. i use Nokia 3310 mobile phone to connect to the PIC.

now i need to connect this GSM Module (SIM300CZ) to my pic, but is don't know how can i do it.

if you can help me, then i can help you to complete your project.

Thanks in advanced.

 

[fiolin]

See this topic I have attached a file called serial_port.pdf wrote by Simcom.
Best regards.