Sideways Topic

[Brian]

I realize that this effort is to produce an Analog Telephone Adaptor
and the projects looks really good so far. I have been looking into a
slightly different application around Radio Communications something
like an Analog Radio Adapter. There are commercial solutions in the
$1-2K range.

In the asterisk project there is a currently a project called Apt-Rpt
with some associated hardware that allows you to connect commercial or
ham radios to asterisk and do some really interesting things. However
the cost is upwards of $100 or $200 per radio channel due to the
specialized hardware.

I am wondering how adaptable this project might be to the following
scenario/interface: (sorry for the simplification)

received audio in - what the radio hears when in receive mode
transmit audio out - what the radio sends when it is in
transmit mode
COR - a logic signal that is set high or low when the radio
receives a valid signal
PTT - a logic signal that is set high or low when the radio
needs to transmit
ground - for all signals

when the radio receives something it sets the COR and the avr would
encode and send out to the network
when the AVR receives something from the network it would set PTT and
decode and send to the radio

The ultimate solution would be to add the ability to back haul via
Ethernet with SIP and RTP but I dont know how hardware intensive that
would be.

If this is too far off topic please accept my apologies.

Brian

[David Rowe]

Hi Brian,

Yes I have spoken to a few people about Asterisk with radio - a few
people are working on variants of embedded asterisk for that.

It would be fairly straight forward to use an AVR for the interface
between an Asterisk box and a radio, all you really need is the A/D,
D/A, and a few logic levels. In fact easier than interfacing to a
telephone, as no hybrid and high voltages is involved.

Cheers,

David

> --
Free Telephony Project
open embedded IP-PBX hardware and software
http://www.rowetel.com/ucasterisk