Basic stamp with bc245 police scanner

Archiver

I am interested in connecting a police scanner to a basic stamp and
controlling it.

I also need some help with serout. What is ttl and how the heck do I
find out wether my radio is compatable?

If anyone has done this or is interested E-mail me
djdunkman@h...

Archiver

TTL stands for 'Transisitor-Transistor Logic', and is a short-hand
for the 0 to 5 Volt logic used in most IC chips, including the
Stamp. Logic '0' is 0 to 1.4 Volts, and Logic '1' is 1.4 volts to
5. Note you shouldn't depend too much on EXACTLY 1.4 volts -- this
is Digital logic after all.

TTL is also distinct from the RS-232 levels, which are more
flexible. A 'Low' there is -12 to -3 volts, (-10 and -5 typical) and
a 'high' is +3 to +12 volts. Typically 232 drivers 'invert' the TTL
signal, so a +5 TTL '1' sent to a 232 driver results in -5 volts on
the 232 line, and a 0 Volt '0' results in a +5 volt signal on the
line.

RS-232 is also standard which specifies how to serialize a Byte into
bits, with some optional error checking (parity). The SEROUT/SERIN
commands do this for the Stamp.

Your radio documentation should have some information on a 'Serial
Port', and the protocol (Baud Rate, Data Bits, Parity) it uses. You
then set up your SEROUT command parameter appropriately (see the
manual) and you should be good to go.

--- In basicstamps@yahoogroups.com, "supergf1" <Djdunkman@h...> wrote:
> I am interested in connecting a police scanner to a basic stamp and
> controlling it.
>
> I also need some help with serout. What is ttl and how the heck do
I
> find out wether my radio is compatable?
>
> If anyone has done this or is interested E-mail me
> djdunkman@h...