[comp.robotics] remote data communication

jrichard@hawk.ulowell.edu (MacGyver) (01/07/91)

   I am trying to reason out how to send a 8-bit signal from my computer's
(amiga) parallel port to my autonomous robot.  Right now it looks like
I'm gonna have to tear apart a radio controlled car controller/receiver.
Is there an easier way?  There must be some ICs out there designed for
this purpose.

   Also, does anyone know of a cheap robot parts mail order outfit.  I'm 
looking for an arm (just needs to pick up light blocks), and a camara
that sends out a low-res digital signal (I'm kind of a neophyte here).
Anything will do here... If have the plans on how it works I'll make it
work for me, I just need to get a digitized photo for vision processing.

					--thanks


<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>
>John Richardson                 |"sundogs fire on the horizon         <
<INet:jrichard@hawk.ulowell.edu  | meteor viens stream across the night>
>Plan:                           | ...the spark still flies            <
<MacGyver-ize programs 'til they | reflected in another pair of eyes." >
>work (pass the duct tape please)|                  -Neil Peart        <
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

6600tjkd@ucsbuxa.ucsb.edu (Mad Hatter) (01/08/91)

 I read somewhere that it is possible to use CHEAP
style walkie-talkies to transfer serial data, it
was rigged up with two tone generators (one for a
binary 1 and the other for 0). So you would need to
get a UART for both ends and two sets of the
walkie-talkies one for each transfer direction. I
may be able to find the reference for you, but i'm
not sure...
 

hbg6@citek.mcdphx.mot.com (01/09/91)

In article <1683@ulowell.ulowell.edu> jrichard@hawk.ulowell.edu writes:
>
>   I am trying to reason out how to send a 8-bit signal from my computer's
>(amiga) parallel port to my autonomous robot.  Right now it looks like
>I'm gonna have to tear apart a radio controlled car controller/receiver.
>Is there an easier way?  There must be some ICs out there designed for
>this purpose.
>
I don't know if this will help but...

I built a system a while ago which used a garage door opener remote control
at transmit parallel data about 500 feet. This takes some serious hacking.

First, remove the 8 or 10 position dip switch from the transmitter board
and interface your data to the input side of the transmitter chip. In the
unit I used, TTL levels worked fine.

On the reciever side, locate its dip switch. Follow the traces to the
magnitude comparitor chip. Also connected to the comparitor will be
a series of traces from some sort of shift register. These traces are
where you pick off your data. I also managed to find a signal detect
line in the reciever to use as a strobe.

This all worked fine and only cost about $35 and several hours work.
( my time was a lot less expensive back then :-) ) Note that there
are dozens of different remotes out there so your kind of on your own.
If I had to do it today, I'd probably use a cheap wireless mike and
a DTMF (touch-tone) chip set.

Good luck,
John

nagle@well.sf.ca.us (John Nagle) (01/09/91)

     This is hard.  I know a number of approaches which produce marginal
results, and will wait to see if anyone posts a good solution.  Modifying
model radio control gear is possible but there are serious problems.
Modifying cordless telephone gear is also possible.  Ham radio TNCs are
a reasonable way to go, as are wireless LANs.  Whatever you do, it has
to have error correction or it won't work.

					John Nagle

craig@ernie.Rosemount.COM (Craig Taylor) (01/10/91)

How about using cordless phones and modems?
Just a thought.
-craig

jackm@agcsun.UUCP (Jack Morrison) (01/11/91)

In article <9575@rosevax.Rosemount.COM> craig@ernie.Rosemount.COM (Craig Taylor) writes:
>How about using cordless phones and modems?

Besides being a bit expensive, you'd have to go through some contortions to
get them to work without being connected to a real phone line (unless it had
an intercom function). What about an FM wireless mike? I've seen little
ones advertised in Radio Electronics for under $15. And 300 baud modems are
pretty cheap these days...


-- 
"How am I typing?  Call 1-303-279-1300"     Jack C. Morrison
Ampex Video Systems    581 Conference Place, Golden CO 80401

ins_atge@jhunix.HCF.JHU.EDU (Thomas G Edwards) (01/12/91)

In article <22502@well.sf.ca.us> nagle@well.sf.ca.us (John Nagle) writes:

>Modifying cordless telephone gear is also possible.  Ham radio TNCs are
>a reasonable way to go, as are wireless LANs.  Whatever you do, it has
>to have error correction or it won't work.

Note that it is now possible to obtain a technician class amateur radio
license (i.e. ability to use Ham band frequencies about 50 MHz)
without having to pass a 5 word-per-minute Morse Code test.
However, you cannot use amateur radio bands for for-profit purposes,
which rules out use by business.

-Tom
 N3HAU