In message  <199604290625.AA29445@scratchy.adacel.com.au> PICLIST@MITVMA.MIT.EDU
 writes:
> Hi,
>
> I am planning to construct a remote frequency counter (personal
> project), for a frequency in the range of 0 to 250 cycles/munute
> (Quite low). It needs to calculate the frequency and output it in
> a serial format at 2400 Baud.
>
> The frequency is to be output at a maximum of one every 5 seconds,
> and may be as slow as once every 15 seconds.
>
> As for power requirements, I need it to
>         1       Use as little poweras possible
>         2       Run off 3 -3.3 volts.


Peter,

You may already know this, but if not, Maxim do an RS232 converter chip
that runs from 3V to 5.5V and produces true RS232 levels.

It is the MAX 3232.

In fact I have run it on the bench with a C71 at less than 2V supply and
still they both worked!

Regards,

Mike Watson

--
Mayes(UK)