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@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
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