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yaesu g-xxxx rotor controller update

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Subject: yaesu g-xxxx rotor controller update
From: (David Robbins)
Date: Tue, 09 Jul 1996 00:37:09 +0000
This is an update on my progress with a controller to replace the yaesu 
rs-232 rotor control module.  this approach is much cheaper and has many 
possibilities for additional features... its all just a matter of 

I now have the controller working with CT, I don't know all the possible 
computer commands that the yaesu rotor uses, but I do have the one that 
CT knows.  I am presently playing with software that would let the 
controller handle up to 4 rotors from one computer(not with CT but maybe 
from other programs?).  each rotor can have different degrees of 
rotation.  I can set up to 12 preset buttons total(lots more possibly if 
you want to encode them).  It does know how to pick the shortest 
rotation distance making use of  the overlap range in the g-xxxx and it 
can handle any stop location.  

right now i have installed it in a g-2700sdx controller for my 20m 
station that has a north stop.  I also tested it in a g-2800sdx that has 
a south stop.  I plan on using it this weekend in the IARU test to see 
how it holds up to rf and such... so far it seems pretty solid even 
without any added filtering.

i checked with the manufacturer about price breakpoints.  They are 
reasonable, but probably not enough to make small production runs 
profitable... at least not with my overhead rates, or experience.  I am 
after all a software designer, not a manufacturing engineer.

the whole system for a single g-xxxxsdx rotor control consists of:

Z-World Micro-G2(b) z180 controller with a/d converter.  costs are:
        MG2B $159(q1) $144(q5) $129(q25) $114(q100) $99 (q500)
        (for more info see )

two 2n2222 or equiv transistors and 2 resistors for driving the 
directional control of the rotor.  (could be done with open collector 
driver ic also to handle multiple rotors)

4 spst momentary switches and 4 pullup resistors (3 presets and one 
program button in my current configuration)

misc connectors.

A 128k EEPROM or (UV)EPROM or (27C010 is listed as one type) I am not 
sure how small a rom i could fit the program in right now, but the 
controller also accepts 27c256 and 27c512.

a 10k trim pot for setting speed.


I haven't played with the eeprom stuff yet but they say you can use it 
for non-volatile storage for your program variables.  They also provide 
for battery backup of the static ram.  It would also be possible to use 
some of the input lines as programming jumpers for common rotor types at 
the expense of some preset lines.  Or as I do it now, you can program 
parameters through the rs-232 port and loose them when you power down 
the controller. (nice for testing, but probably not for production)

The trimpot i am using could be replaced by programming some output 
lines and adding some more resistors to make a dumb d/a to provide 
software control of speed.  Its interesting that the front panel speed 
control doesn't work when you use the internal left/right control lines.

Other options could be to add relays to the control outputs that should 
make it possible to control any rotor that has an analog position 
indicator and left/right(or up/down?) pushbuttons.  Z-World also offers 
a 6 relay board but the price seems a bit steep, but you can daisy chain 
up to 64 of them if you have a BIG antenna farm to control!  I really 
got this thing to play with different switching controls for antennas, 
with the addition of relays i think i could build one hell of an octopus 
with this thing.... or just add ptt safety to pushbutton antenna 
switching.... or make a smarter band switching controller that could 
read the parallel port outputs... or... well, lots of stuff, its just a 
matter of software after all.

I guess what I am looking for now is suggestions or volunteers.  I could 
write up an article for do-it-yourselfers, but would need a way to 
reproduce the rom.  (the software development kit is $195 for anyone 
that would prefer compiling it themselves to eeprom)  Or someone could 
produce the small additional board for the pullup resistors and switch 
drivers... (the prototype board with power supply cube goes for $129, 
which gives you the eeprom, a 2" square proto board with a buzzer, 2 
leds, 2 switches and some jumpers, and its just a bit too high when 
attached to the controller to fit in the yaesu box.... but just think of 
the possibilities of those leds and the buzzer!)

so, anyone out there with any ideas or suggestions??

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