Subject:
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Re: Newcomer
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Thu, 19 Dec 1996 12:47:01 GMT
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Original-From:
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Fred G. Martin <fredm@media.mit.edu{Spamless}>
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Viewed:
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2296 times
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> We have the parts list and I guess the next thing to do is to order the
> parts and get
> the boards. Now, we have several questions:
> 1. Which 68HC11 to get: the ...A1 or the ...E1?
either. some people like the e1 better because it has more flexible
timer and counter lines. but the a1 has a simpler bootstrap sequence
and is less likely to have compatibility problems with the host
computer.
> 2. Do we just put in the parts list to Digikey or Jameco or is there more
> to it?
No, it's harder than this. There is not any one single supplier that
has all of the parts. 90% of the parts can be bought at Digikey, but
there are about 6 or 8 parts that are a pain to buy in small
quantities. Check the mailing list archive and you will see periodic
messages like "help, how do I get an L293D chip" "help, how do I get a
DS1233-10" "help, how do I get an IS1U60."
Also, you won't really save much money ordering one kit's worth of
stuff yourself once you get past the shipping charges/minimum orders
from multiple companies. In fact it may cost more.
I *urge* you to please order a complete kitted system from the Handy
Board suppliers.
> 3. What kind of logic probe to get and where do we get that? Can't afford
> an
> oscilloscope.
the simple true/false/pulse type. costs around $20 from Jameco.
these are great to have when debugging.
> 4. We figured we would need an analog output (through a DAC?) to feed into
> the R/C transmitter - eventually. Where would that fit into the scheme
> of
> things? Can a DAC be controlled by the 68HC11?
you might want to interface the hb directly to the car's motors,
bypassing the rc ckt entirely. check the mail list archive for ways
of doing this. one way involves tapping into the final stage of motor
drive circuit on the car's electronics (after the rc stage). this
uses the power transistors already on the car, switching them from the
hb.
-fred
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Message is in Reply To:
 | | Newcomer
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| Hello: First - thanks for all the good information that we were able to find on the handyboard web page and on the associated ftp site. My son and I have decided that we would like to build the handyboard rather than buy one ready-built. We have no (...) (28 years ago, 19-Dec-96, to lugnet.robotics.handyboard)
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