old tech teardown – handheld controller from an old microwave radio

not sure how how interesting this is
going to be for you guys but this is something was tossed at work that I’m
sort of curious about so I’m gonna pop it open and see what’s inside it so this
is the one of the control methods a handheld control panel from Harris or
Harris fair and on or through a various different names but Harris is the main
company from Harris microwave the truepoint five thousand line or range of
microwaves microwave radio it was let’s see now so Harris made this radio
for about five years from 2005 to 2010 and they don’t seem to be into these
point-to-point telecom carrier grade microwave radios anymore as far as I can
tell from their website they’ve moved on to a lot of military communications and
a bunch of other interesting niche stuff they do space-based communication stuff
I guess there’s more profit in there in that kind of stuff even though there’s
OS potential customers anyway um that’s an aside so these are rapidly coming out
of service I mean it’s seven eight nine years since
its so since they stopped supporting them so I guess it’s probably do anyway
so there’s a bunch of different ways to talk to this to this radio system this
was the absolutely most basic one it just plugged into a port on the front
and it gave you a foreign menu needs scroll through and talk to the thing and
you could do some basic stuff like turning on and on on and off different
transmitters and switching the receivers you turn on and
off different traffic ports on it and probably the most important thing the
most basic thing that it was it used for at least once on every installation was
to set the IP address of the unit so that then you could log into it with
your laptop using its built-in web server and do all the programming a lot
easier that way but this little keypad has got me out of so many jams when I
couldn’t get my laptop to boot or I was too easy to bring me in there whatever
what’s holding up together I guess those little nuts there there
there we go a TBT nut driver somebody’s gonna ask oh
come on up asana loosen you’ll have to crack it open crack up luces pliers and
then spin it off of the neck paper there we go it’s not perfect but it’ll do
somebody’s gonna ask this nut driver came in a set from princess Otto they
got years and years and years ago so how does that come out there we go uh-huh
hung out here called he passed okay so two thousand six seventh months was when
that was built and inspected which is odd since these the stamp on the plastic
injection molding since 2006 and eight months hmm somewhere in that range
anyway 2006 which is a year or two after this model was introduced but not not
much after we have the little display board which
does it identify what it is on the back not really TM tool for J a a 7p one okay 20 columns
and four rows possibly that seems about right
I wonder if I can repurpose that for something anyway here’s the here’s the
fun and games in here and will that pop out well I think it will you guess it
real okay a rubber keypad on the back which is just one of those the resistive
things that make contact down there that’s not at all surprising and on this
side what the MC 68 HCP 11 e 1 CF n3 presumably the the main processor that
guy with the sticker on him is probably the wrong for this little module they
have an oscillator over there which isn’t surprising because there’s a
little processor in here you have each C 5 7 4 D by Phillips and each C 5 7 3 D and if I’m measuring if I’m looking at
this right it looks like they’re connected to each other and then
connected over to the serial port so that probably I’m assuming that’s a
serial port it’s actually probably got other things going on because this
thing’s also got to get power from their power and I’m guessing serial data in
and out so those are probably the serial drivers and
yeah so that that’s not going to be a standard rs-232 pin out because it’s got
to get 5 volts and ground from it because I’m guessing it’s not anyway and
H int32 C B’s ed whatever that guy’s doing there’s nothing obvious it might
be that it might be part of the display driver though and the other chip down in
the corner there that I initially thought was part of the display or the
display driver appears not to be and therefore was probably wrong about what
those two eight port devices were doing earlier – this says the H a in two three
– and it is an rs-232 driver so that’s clearly what it’s doing so I wonder what
those other guys are doing so after the data sheets confirmed some of my guesses
and blue some of them out of the water let’s quickly go through so we got the
microcontroller EEPROM this is the 8-bit latch and the bit flip-flop which now
that I look at them the little bunch of vias which come down onto this side and
go to the keyboard which is a four by four matrix so that’s probably what
they’re doing well that’s fairly clearly what they’re doing and then this guy is
the rs-232 and yeah not too much else to see on here just some common logic chips
and stuff like that so somewhere on this connector there’s going to be five volts
and ground there’s going to be rs-232 which is TX and rx and I don’t know what
the other pins are doing if anything on this side of the board we can see that
there’s only really three pins connected off four pins connected that looks like
ground that one looks like he’s got a resistor
to the ground clean there’s gonna be a TX and rx data and presumably a five
volts now then there could be stuff happening on the other side of the board
and it looks like there might just be but because of the connector we can’t
really see it supposed to go back and find the five volts on one of these
chips and see if I get find it on here that might be interesting okay so
there’s ground on pin one of the db9 and I’ll pick up VCC off this chip here and that’s one diode junction above ground
higher above VCC and bow VCC and there we go that is VCC itself on that end so
let’s see what happens if I get some power on this thing I’m not sure if this
is gonna work or not without anything communicating with it
there might be a backlight I can’t member but we’ll see so there’s that
I’ve got five volts in the power supply and we’ll see if anything happens
power on nothing happens it’s not drawing any current to speak of nothing
that was worth a try I guess yeah the five volts is getting onto the board so
I don’t know um that was a long shot anyways but it’s always interesting to
see what’s inside something that you’ve just been taking for granted at work for
you know a decade or more I may play with this a bit more in the
future that that display looks interesting if I can find any
information out about it unfortunately everything’s all in blobs here so well
actually maybe I’ll just do a quick search for that part number there I
didn’t do that oh hello hmm so it is a fairly off-the-shelf item
and relatively common although I wouldn’t pay that much for it but it’s
interesting that that’s what they think they can get for it even more
interesting a datasheet 4.3 volts for the LCD 5-volt logic tolerant blue and
black and white blue or black and white what do we got here 5 by 7 dot character
talks 8-bit parallel there we go 20 characters by four lines is reflective
no backlight oh ok and the LCD is positive type you know three digits 20
characters that’s what we thought power supply max 7 volts we can run it
straight off 5 volts that’s awesome I may actually be able to use this thing
oh and there’s our data bits Oh awesome that should be fun to play with I made
actually little selfish that out of there so after looking at to the data
sheet for that LCD it occurred to me that the in might a box of displays here
in amongst the 1602 and the nucleus and stuff that looks oh it’s a big brother
of it never mind and that one’s got an SPI adapter on unfortunately I’ve got
another one would that actually line up no not really
but I think with the P note that I got from the datasheet it’s probably gonna
be pretty close to these guys I’m guessing and hopefully
somebody some nice kind Arduino person has written a library that I can use but
that’s another thing for another time today was just about satisfying the
curiosity and seeing what’s going on inside here and that’s been done and
then some actually so oh yeah hope you found that interesting or
amusing umm I was never really intending for that to get that deep in the reverse
engineering or into the potential stuff but yeah there you go
I mean also try a little bit more and see if I can figure out what’s going on
there but I don’t know without without a bit more information it’s gonna be a bit
tricky I could probably chase the serial port
back to there but I still didn’t get any indication when it lit up there was no
boot message or anything you know so I don’t know well we’ll find out anyways
thanks for your time um I appreciate you stopping by to see what I’m up to
given the questions or comments I’m not sure if I can answer the questions but
what the hell throw them at you throw them down in the comments anyway and
we’ll see what we can come up with thanks doctor


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