13 Jun
2012
13 Jun
'12
5:08 a.m.
On 06/12/2012 03:55 PM, Tony Duell wrote:
Yes.
I literally cannot remember the last time I had to do anything with
other than 2, 3, and 7. Even one of the controller designs I inherited
at work had a bunch of firmware to manage RTS and CTS to talk to a GSM
modem at 115Kbps, and it works better with that code commented out.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
Yes!
That's exactly what I do, but I don't recommend it anymore
because the response is usually "I don't have one of those things with
LEDs and they're so EXXPEEENNSSIIVEE!!" (they're like ten
Err, right...
While I can understnad not wantign to spend hundreds or thousands of
dolalrs on tools and test gear just to get one machine up and running, I
do think that spending $10 ro so to get the machine working is well worth
it (hint : If you had to pay me for my time in sorting it out, it would
be a lot more expensive than that :-)), and anyway, an RS232 tester is
something you'll ened aagian and again if you work on classic computers. Can you stil lget tyhose LED adapters? At one time
just about every PC
shop sold them, but now, since RS232 is out of fashion, I;'ve nto seen
them on sale for several years.
PC shops sell new PCs and games, that's about it. The world's
marketplace has moved to eBay. You can get them (brand new of
course...a lot of people think something is "used" or "old" if the
sales
venue is eBay) all day long, cheap, on eBay.
It's not hard to make one, but...
...but a complete waste of time, unless you've got nothing better to do.
bucks...cheapasses) But yes, that works perfectly. Something needs to
be driving TxD, and something needs to be driving RxD. Which is which,
and what state they're in, is unimportant if the goal is to get it talking.
The other trikc is to see what flow control lines are being driven, and
it noting works, to try loppign them back to what they normally pair with
(e.g. if pin 4 -- RTS -- is being driven by a device and you can't get it
to sand anything, try connecting RTS to CTS (4 to 5)). You migth end up
with a thing that drops data due to buffer overrun from time to time, but
you sort that out once you've got it sending something.