--- 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