Subject:
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Re: Serial LED is not lighting up during charger board assembly
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Sun, 26 Aug 2001 22:15:57 GMT
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Viewed:
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1669 times
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Hi Scott,
as I mentioned before i only assembled some 6.270 boards, but no handyboard.
So what's follwing is only what i guess.
I can't check this out here.
Are you able to measure (always with pin7 J9 as ground reference) +9V at
pin2 U16 and -9V at pin6 U16 ?
If so then you're connecting pin6 U16 to pin2 J9 (or pin 8 U16 which is the
same). That means -9V to the (resistor in series !! or our LED will light up
bright but a short time and only once !) cathode of the green LED. The anode
should be connected to ground in the circuit (pin7 J9 and the anode of the
LED should have a connection).
(Have a look at hbmanual.pdf page 52)
When doing so the LED should light up.
If not your LED might be blown or the wrong direction, but you're sure that
it's not. Or your resitor in series with LED is blown (or the wrong one, it
limits the current of the LED. So if it's the wrong one the LED won't light
up (or one short time, very bright :( )
Regards,
Rainer
In lugnet.robotics.handyboard, Scott Hazel writes:
> I'm in the middle of assembling the Serial Interface and Batt. Charger
> board but have run into a snag. While testing the serial circuit, I was
> able to see the +-9V values on pin 2 of U16. However, when testing the
> transmit and receive functions of the MAX232 chip, I can't get the green LED
> to light up. There are no troubleshooting/debugging tips for this section.
> I'm pretty sure
> that I installed the LED correctly. The short lead is the cathode
> (negative) and goes into the square hole for SER LED. If this LED was
> installed backwards, would that account for getting the right voltages but
> no light?
>
> One caveat on my part, I misunderstood the directions and have already
> installed the 25pin Serial connector (J9) so I've been making my
> measurements with a bare lead inserted into the proper hole (pin 7, etc.) I
> don't see how that would impact this problem but its best not to leave any
> details out. Any suggestions on how to troubleshoot the serial LED not
> lighting up? Thanks.
>
> Scott
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
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