[aprssig] has anyone built/modified a USB to TTL level converter??

Jason KG4WSV kg4wsv at gmail.com
Thu Jun 2 11:11:26 EDT 2011

On Thu, Jun 2, 2011 at 9:58 AM, Bob <k8ys at fuse.net> wrote:
> I think that I want to take an old cell phone to computer interface that has
> a USB to RS232 level converter.

USB to RS232 is not a "level conversion".

If your cable speaks RS232 voltages and levels (+12V/-12V), the MAX233
will take it back to TTL voltages and levels (0V/5V).  Put the MAX233
at the radio if the cable run is very long, as RS232 is made for
longer distances, and TTL isn't.

If your cable speaks TTL voltages and levels, you already have what
you need, just wire it up.

> Without reinventing the wheel, is there a "better way"?

FTDI TTL-232R-5V :

5V TTL RS232, built right in to the cable.


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