[arm-allstar] txctcss

[Pres W]

Hello. I have some questions about txctcss. Sorry about how crazy long this
is, I'm trying to be clear.

txctcss as described:

"...the intended use is to enable a hardware ctcss tone inserted on the
transmitter. The allows the output PL to follow the input PL on an Allstar
repeater. Since this bit follows the composite cos/ctcss input..."

Actually, when I enable it and then invoke the function, it follows
-EITHER- composite cos/ctcss input -OR- incoming Allstar signals. Which in
itself is not bad, because the user's radio hears both halves of the
conversation, local repeated audio and distant Allstar traffic. HOWEVER:

When I add the following line to the /etc/asterisk/simpleusb.conf file -
gpio7=txctcss
OR
gpio7=txctcss_invert

BOTH SEEM TO WORK IDENTICALLY!

See, here's the thing. I could really use gpio7=txctcss_invert to work,
because I'm using a PL-Mute line in my TX.

Not a ground-to-encode, but rather a ground-to-not-encode. Motorola calls
it "PL strip".

So ideally it will be asserted (low) when the PL is supposed to be off
(muted), and relaxed (open) during incoming RX or Allstar audio when people
want to hear things.

Once either line is included in simpleusb.conf AND then I enable the bit
using rpt cmd <node> cop 58 0, then the PL UNmute follows RX//Allstar as
expected but when I DISable it using rpt cmd <node> cop 59 0, then the PL
is always muted. Let me phrase that differently: If the txctcss function is
allowed, then I have ALWAYS-muted when off, and
unmuted-when-people-are-speaking when on.

Seems to me that as it is, even if I were to invert the GPIO7 line with an
NPN transistor, it would not mute when the function is off (as expected),
but it would act backwards during signals, by muting during transmissions
and not muting between.

Question 1: is this supposed to encode following both input signals AND
distant linked signals as I have discovered?

Question 2: why do you think the non-invert and the invert choices act the
same? Is this a bug?

Question 3: how do I allow the option to use it in simpleusb.conf without
it always muting when disabled? This is the main problem I have.

Question 4: is all this shenanigans I'm facing due to the fact that my
repeater requires ground-to-mute-PL rather than ground-to-encode-PL? It's
not clear exactly how one can "...enable a hardware ctcss tone inserted on
the transmitter..."

BONUS Question: can this be set to NOT MUTE (encode) during the entire
repeater's transmission, then mute (stop encoding)
just-before-the-TX-drops? This is known as "chicken burst" in some circles,
and is actually my goal.

Thank you

-Pres W2PW