Tracker2 with LCD display
- Since trackers with LCD displays seem to be the popular thing these
days, and I'd already done it with the OT1+, I figured I'd take a shot
at hooking a display up to a T2.
I set it up for a 4x20 display - unfortunately the only 4x20 display in
my junk box turned out to have the minor flaw of actually being a 4x16,
so that's what it uses for now.
Here's the result of about 2 hours of messing around with it, most of
that time being devoted to fixing my wiring errors and chasing down the
code that was using one of the 'unused' pins to output diagnostic
information for the demodulator.
The LCD driver code doesn't take much space, and there's no new parsing
involved so far (it was already calculating distance and bearing), so
I'll probably just leave the code in there and enabled in the next
release, no need for a new config option.
So far it just displays call, distance, bearing, and comment. Wiring is
direct to the MON08 header, plus a resistor on the contrast pin and an
extra ground lead to the RW pin. And HD44780 compatible display should
The extra unconnected wire could be connected to a pushbutton. I'd
really like to have at least 3 buttons, and preferably 4 - up, down,
select, and exit. A rotary encoder like the HamHUD and D710 would be
faster. To get extra I/O lines it'll be necessary to run wires to the
other header, though.
Obviously there wasn't a lot of new code involved in getting this
running, but I haven't offered it as an option previously because I
wanted to have something with a nice case and I didn't have time for the
extra tech support. But if you want to wire up your own, I'll be happy
to provide the beta firmware and the wiring diagram. Just keep in mind
that I reserve the right to ignore support inquiries, feature requests,
and complaints until I have time to make it an officially supported
> - display outputs gibberish characters on lines 1/3 when T2 writes to it. But I never see gibberish on lines 2/4Power up sequence? What Power up sequence? Ohhhhhhhhh, you mean *that* power up sequence.
Fred tells me the following in an email "The LCD has a particular startup sequence and this will only be done at the T2 startup."
Whereas, I took the WIKI quite literally "No configuration is necessary. The standard Tracker2 firmware will begin using the display automatically. "
So, I just plugged it in, hot. What a newbie mistake!
> -I put an SPST switch on +5v input (pin 15 on the mono8) andBad switch - still delivering +3.9V power in the OFF position
> here's the really weird part. When I turn on the switch, the display and the backlight LEDs come on. When I turn off the switch, the LEDS remain on, but dim down a bit.