Lpc2000

Well...just to let you know..at least Texas Instrument MAX232 accepts
2V MIN as a High-Level Input Voltage
and 0.8V MAX fot TTL as a Low-Level Input Voltage. So I will test 
MAX232 and put a 3.3V Zener at the receiver output of the MAX232, 
just in case... Or should the RX and TX pin of the UART in the 
LPC2106 be 5V compatible?
Thanks
Ezequiel Aceto

--- In lpc2000@yahoogroups.com, "J.C. Wren" <jcwren@j...> wrote:
>     I may have missed this if anyone mentioned it before, but if 
you're 
> building that aren't going to be shipped to end users, a MAX232 
runs 
> fine at 3.3V.  You get +-6.6V out of the charge pump, instead of +-
10V, 
> but 6.6V is well within the RS-232 spec.  I used Sipex and Maxim 
parts 
> all the time in this configuration for prototyping, or whipping up 
a 
> quick RS232 interface to a logic level device.
> 
>     I know there was more in this thread, but my mail server 
swallowed 
> it, so I apologize if this idea has already been mentioned.
> 
>     --jc
> 
> Robert Adsett wrote:
> 
> > At 10:45 AM 12/11/04 +0000, you wrote:
> > >Unfortunately I cannot obtain any RS232 Driver for 3.3V, yes 
for 5V.
> > >In My LPC board I have 5V, so I was thinking about adding some
> > >transistor and convert the 3.3V from the LPC2106 to 5V and 
viceversa
> > >for the RX pin. I know this is not the best solution, but I 
think it
> > >could work. If not, what about making a Level shifter with
> > >Transistors? Does anybody have a schematic, or can help me with 
this?
> >
> > In addition to all the pointers to 3V level convertors I would 
add;  Why
> > not just use a 5V level convertor since you have the 5V 
available?  
> > Run 5V
> > to you level convertor and then hook it's Rx and Tx lines to the 
> > micro.  If
> > your level convertor is TTL compatible then it's inputs should 
match the
> > drive output.  Check the VIH rating of your convertor.
> >
> >
> > Robert
> >
> > " 'Freedom' has no meaning of itself.  There are always 
restrictions,
> > be they legal, genetic, or physical.  If you don't believe me, 
try to
> > chew a radio signal. "
> >
> >                          Kelvin Throop, III