"The Link" interface board

David McKenzie k1fsy at vhfwiki.com
Sun Sep 29 10:21:55 EDT 2013


I figured it either turned invisible or was ultimately made up and was thus
illusive!

=D

Some pics which I thought I attached to the first message


On Sun, Sep 29, 2013 at 10:13 AM, David McKenzie <k1fsy at vhfwiki.com> wrote:

> In anticipation of assembling the link in some sort of "final"
> configuration, I decided that in lieu of the illusive Nomic that was
> originally destined for this project I would put together a plug-in board
> for the RasPi that has similar features.
>
> I have 3 copies of the board being printed (at the bargain price of $15).
> It exposes seven GPIO ports for PTT and other features of the radio that
> may or may not need to be controlled, and the pins from the header also
> allow for "green wire" mods for analog or digital inputs if necessary.
>
> It also has +5V/GND connection to power the raspi from an external
> powersupply/voltage converter rather than USB.
>
> There are two 3.5" stereo phone plugs, one plugs into "audio out" from the
> RasPi itself, the other is for a monitor speaker if desired. Audio from the
> rig to the RasPi is to connect directly to the USB sound dongle (not in the
> schematic), and audio/ptt out to the rig is via an RJ45 jack with jumpers
> to select which pins do what. The audio from the RasPi to the radio goes
> through an isolation transformer and can be varied in level by a 10k pot. I
> "borrowed" the audio circuit from the Nomic schematic (it's identical to
> pretty much every other rig audio interface circuit I saw as well), so
> hopefully it works out ok.
>
>
>
>
>
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