On Wednesday 02 January 2008 22:10, Gene Buckle wrote:
I used an LED to watch the output on the 1488.
With an appropriate current-limiting resistor I would assume?
The LED lights the instant I attach it to the output
and doesn't flicker or
go out when I reboot the computer to make it send data out the port.
The little tester I have for rs232 stuff uses bi-color LEDs, makes it easier
to see what's going on.
The Port should be running at 9600 baud, so I should
see at least some
flicker activity on the LED if the 1488 is toggling the output pin.
Before I spend the time to replace the 1488, I'd like to hear from you
folks if the chip is actually bad. Is what I'm seeing indicative of a
dead 1488?
Could be, I've certainly replaced my share of those. And put sockets in
while I was at it. :-) Just make sure it's getting the proper power
supplies, as if one or both of them are missing you won't see proper output
then, either.
Whenever you're trying to troubleshoot anything, always verify the power
supplies first! I forget that myself from time to time, and have regretted
doing so.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin