> 1) Any chance we'll see an OT2m model with GPS input via some form of
> USB connector? USB output is becoming common on puck-type GPS receivers.
Here's some information on why it's not so easy:
The T3 does theoretically have some capability for acting as a USB host,
but it's not going to have the code space to be practical, and it can't
really support both a host and device USB connection.
> 2) Same question for future OT1+/OT1-USB series, or successors?
The dual-port tracker/TNC I'm working on will have more USB host
capabilities. Support for USB GPS receivers will still be limited by
what I can reverse engineer without access to driver documentation.
Anything that is supported with open source drivers (e.g., on Linux) is
at least a candidate. I suspect that supporting two or three serial
emulation modes will cover the majority of devices out there, but I
can't be sure until I test a bunch of them. It will probably require
maintaining a list of VID/PID numbers for supported devices, too.
Supporting serial I/O on a typical micrcontroller takes a few lines of
code to send and receive data. To support various serial-over-USB
devices, check out how much code the Linux kernel uses:
Supporting ALL of those devices would probably take more code space than
the device will have.
> 3) Might future OT1+/OT1-USB models accept Garmin proprietary input?
Never for the OT1+. It just doesn't have the RAM. And it's about out
of code space, too. The product is basically end of life - we're going
to keep the kits in stock and make maintenance updates to the firmware,
and maybe some minor feature additions, but I wouldn't expect any major
updates on it.
The OTUSB is actually part of the T2/T3 family. Digipeater and Garmin
support *can* be compiled in, but there's no room to fit it all. I'm in
the process of making the code even more modular, so you could more
easily exclude other portions (scripting and weather, for example) or
add in seldom-used modules (e.g., Nonin pulse oximeter support) so it's
certainly possible, but I don't really want to try to support 2^n
different firmware versions.
It's worth noting that the OTUSB and T3 processors are pin-compatible.
The only hardware difference that would cause a problem (so far) is the
RS-232 transmitter polarity, and I will probably try to add a hardware
detection feature for that. So any board designed as an OTUSB could be
produced as a T3 variant - though at the moment that means 2-3x the
power consumption. That may change as I get more power management code
written, but I would expect the T3 to always have higher power requirements.