Re: [Gumstix-users] Max232 for 5V <-> 3.3V conversion

[Dave H. <dhy...@gm...>]

Hi Martial,

> I need to connect my old 5v Avr mega128 based board over the serial connexion
> of the new Verdex Pro. I would like to prototype a bit before I build my own
> carrier board and get the verdex signal from the Console breakout pads.
> However these are still 3,3V.
>
> Does someone knows a 3,3v to 5v level converter in DIP package which would be
> widely available?

DigiKey 568-1008-5-ND is an i2c converter that should also work for
serial. It's generic part number is NXP P82B96.

You can go with something like this:
<http://www.sparkfun.com/commerce/product_info.php?products_id=8745>

For logic level serial lines, you can probably get away with just
connecting the 3.3v Tx line directly to the 5v Rx line (since 3.3v
will still be seen as a logic high), and using a voltage divider in
the other direction (like the Sparkfun unit does). The Sparkfun one
uses 2 10k resistors, which would take your 5v down to 2.5v, which
will be seen as a logic 1 by the 3.3v system.

Here's a bindirectional one (you could make yourself)
<http://www.headfuzz.co.uk/?q=node/46>

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.DaveHylands.com/