Lpc2000

--- In lpc2000@yahoogroups.com, "Joel Winarske" <joelw@i...> wrote:
>
> > I have MCB2140 board from KEIL and I want to connect MC35i GSM 
> > modem with the same on COM1 of lpc2148.
> > 
> > The port given on board is not fully connected as there are only 
> > two wires connected Tx and Rx. I want to make a data call to 
> > another PC and the at command is ATD<NUMBER>
> > 
> > Problem is if i m transmitting this at command or say any data 
> > from board to PC using serial comm, I can receive that on PC.
> > But when i am sending same command to GSM modem from my board I
> > am not getting any responce resulting there is no ring to the 
> > other modem which is connected to PC.
> > 
> > I want to do it with two wire only so need your help..
> 
> You should confirm your device (MC35i GSM modem) does not require
> hardware handshaking.  A quick test would be to only wire 
> Tx/Rx/Gnd to PC.  Be sure to read the documentation of your modem, 
> that is the key.
>

I've few pcs of TC35 and MC35 here and connected to my own LPC2124
board before. I've DTR and RTS (Pin4 & 7) of the DB9 Male connector
connected to Pin2 of MAX232 (10V charge Pump).

It's working fine. But I'm only using the SMS commands:
  AT+CMGS=<<PDU>>

My baud rate is 115,200.  I don't hit GSM data rate bottleneck as 
I do not transfer modem data.   May be you should use 9600 to avoid 
hitting the GSM transfer rate limit. The TC35/MC35 should be able to
autobaud if remembered correctly.  
Regards