Interfacing SIM300cz GSM Module with PIC16F MCU

[sam781]

I have a GSM module (SIM300cz) in my hand right now. I want to test this module by sending SMS using PIC MCU. To test the Module I wanted to interface it with my Laptop first. To avoid complexity I planned to use PIckit2 UART tool. I connected UART Rx Tx with SIM300 Tx Rx. But it is not working. When I send AT command it should respond as OK. But it doesn't response.

 

[jayanth.devarayanadurga]

Post you SIM300cz datasheet. Does your GSM module have Rx and Tx (TTL) headers or does it have RS232 port (D connector)?

 

[jjeevan007]

do u serial port in ur laptop or not............

 

[sam781]

Hi jayanth.devarayanadurga,

As per the datasheet, it has RXD and TXD pin. Here the datasheet -
http://www.datasheet.co.kr/download.php?id=684969

Do I need to short all the VBAT pins (pin 1,3,5,7,9) and short all GND pins (2,4,6,8,10)? Or they are internally connected? I just use pin 1 for BBAT and pin 2 for GND. I took SIM GND from pin 4.


@jjeevan007,
I do not have serial port in my laptop. To avoid the complexity of logic level shifting activity I chose to use Pickit2's UART tool. I did UART data Tx/Rx testing of PIC16F628A using this UART tool. Everything found okay. Its very easy to send data by setting baud rate in the Pickit2 tool. I used mobile phone battery to power up the Module.

 

[jjeevan007]

can u post the circuit...................

and u required current of 1amp initially to configure the GSM...............

 

[sam781]

I just connect pins as per the circuit shown in this link - https://www.8051projects.net/t51427/embedded-gsm-development/gsm-module-sim300cz-interfacing.htm

Though the Module shown in the link is not same as my one, pin functionality should be same. Please suggest if i need to change any connection. I used almost new battery. Should I need to change it?

Can you please comment on this query?
Do I need to short all the VBAT pins (pin 1,3,5,7,9) and short all GND pins (2,4,6,8,10)? Or they are internally connected? I just use pin 1 for BBAT and pin 2 for GND. I took SIM GND from pin 4.

 

[sam781]

After giving power to the module how can I be able to understand whether the module is properly powered up and ready for issuing AT commands? Is there any pin where In can connect LED indicator?

I did not get SIM300cz module in Proteus and Eagle to make the circuit to share here. Please let me know if there is nay way to draw schematic of SIM300cz.

As per the schematic shared in the earlier post, I connect the SIM properly with the respective pins. Power connection in VBAT and GND pin. PWRKEY for switch on the device. And RXD, TXD, GND for serial data transfer. Is there any other connection needed to make it work?

 

[js]

Hi
Wye not read datasheet?
ALL is there!
Power recommendation, led status, ...... And yes! All GND pins wire to gnd!