[App_rpt-users] USB FOB options

[Andrew Errington]

The modification for packaged chips usually puts COR onto the Volume
Down pin, so that should be the same for the epoxy-blobbed version.
However, PTT is wired to a GPIO pin, which is not accessible on the
epoxy-blobbed version (so sad that it's not bonded out to a test point
on the PCB, but I digress).  Anyway, I think it would be possible to
tie PTT to the Mute LED output and use that, since if the mic. is
muted during Tx then it's not a problem.  The software would have to
be modified to set and clear the Mute state based on the desired PTT
state, instead of setting and clearing the GPIO.

I did some work with Thomas Sailer's soundmodem software to support
CM108 GPIO (which I also copied to hamlib), but I never looked into
how to set or clear the Mute state.  If the software could be modified
in this way it might pave the way to using blobbed chips, which are
much more common than packaged parts.

73,

Andrew
ZL3AME

On 07/03/2014, Steve Wright <stevewrightnz at gmail.com> wrote:
> Okies, so these USB FOBs have a blob of hard (epoxy?) goop on the chip so I
> can't get at the pins.
>
> BUT, the device has two LEDs and four switches that go direct to the chip.
>
> Why do we need any more I/O than that?  Do I even need access to the pins?
>  I should be able to take PTT off one of the LEDs, and put COR onto one of
> the switches.
>
> Why not?  Soldering to pins is the hard way, and lots of devices are
> potted.
>
>
>
> Steve
>
> --
> Meshnetworks - Rangitaiki Plains Rural Broadband Internet Providers
> +64 21 040 5067
>