siemens mc35i GSM modem interface with my controller

[bhimanipankaj]

Dear Friends.

I am facing a problem with MC35i GSM modem from Siemens.

I need to connect the MC35i GSM modem with my ARM7 based microcontroller which is LPC2148. I have one evaluation board of LPC2148 which is MCB2140 from KEIL.

I need to connect the MODEM to one COM port which is connected with two wires only Tx and Rx using MAX563 as charge pump.

When I am sending these AT commands connecting the modem to Computers COM port it's responding easily but while connecting this MC35i GSM modem to my evaluation boards com port there is no response to any AT command.

So, I have tried to send the data from my evaluation board to Computer and this time it's taking the data.

But sending the same to Modem is not giving responce. I am just sending a command ATD<number>; for a voice call to my cell phone but there is no ring so showing no responce from Modem.

Should I make some changes in hardware?? I want to do it with two wires only, even though I have tried to give +12V permenantly to the PIN7(RTS) of the modem. But not able to get anything.

Is this because MAX563??? should I replace it with MAX3232 or problem is somehwere else.

Please guide me as struggling from long time now.


My email address is bhimanipankaj(at)gmail(dot)com

Thanks and Regards,

Pankaj

 

[Pommie]

I don't know the modules that you are talking about but, if your PC talks to both modules and they won't talk to each other then they are both wired the same way. If you are using a straight through cable (simply an extension) then both your modules have pin 2 as data out. This is connected to pin 2 on your PC which is data in. When they are connected together then you have data out connected to data out.

It sounds like you need to swap RX and TX on one of the boards. I say sounds like because I maybe wrong and you need to check the actual pins first before you swap them.

HTH

Mike.

 

[bhimanipankaj]

Thnx Mike

Dear Mike...

Thnx Mike, thnx mike for the solution for which we were struggling since last one month.

Ya, After reading your reply I was just laughing on myself that this is what missing was common sence in my approach.

I salute you and thnx again.

Pankaj

 

[Pommie]

Glad that I could help.

Mike.

 

[hot_ice]

Hi Pankaj, will you please send me the documentation for your project? I'm doing a similar sort of project. Please email me all the details at: moazzamshafique(at)hotmail.com
Looking for an assertive response. THX!!!

 

[vikas_marath]

hi pankaj, i require a favour from u dude.cld u please tell me the unused pins in mcb 2140 board and whr shld we connect the lcd.Please help me out in this sitution to id
vikas.m(at)arkatek.org