Order Tray | Contact Us | Home | SIG Lists

[russ at wxqa.com: RE: [wxsig] T238+ Characters and Heat...]

Scott Hedberg scotthedberg at msn.com
Mon Sep 18 20:12:48 UTC 2006


Adjusting the potentiometer makes the black squares more black or less 
black.  I had initially adjusted the potentiometer during the setup and the 
text was very readable before.  I was also able to input all the parameters 
into the T238+ after I attached the weather station and did confirm that the 
display was showing me temp, wind speed, and wind direction.  The heat sink 
was only warm to the touch.

I powered back down and then attached the radio interface (DB9 on the modem 
board), powered everything backup and got the black squares and the very, 
very hot heat sink.

I disconnected the radio interface, powered up, and am still getting the 
black squares and very hot heat sink.  The heartbeat LED still does what it 
should be doing.

I disconnected the modem board, powered up, and am still getting the black 
squares and very hot heat sink.  The heartbeat LED still does what it should 
be doing.

Did I accidentally short something or otherwise fry one of the components?

73 Scott AD7MI




  -----Original Message-----
From: Beals, William [mailto:William.Beals at echostar.com]
Sent: Sunday, September 17, 2006 2:58 PM
To: russ at wxqa.com
Subject: Fw: [wxsig] T238+ Characters and Heat...

   Scott:

   The regulator does get hot as Mike points out below. This should be the 
case if the weather head is plugged in or not. Lower main supply voltage is 
the best "cure".

   A good experiment to try is hot plugging and unplugging the weather head. 
It won't hurt anything. If plugging in the head makes the LCD go from normal 
to black squares, the something fishy is going on. It looks like +5V is OK 
as the cpu is still working. The LCD also relies on a -9V supply from the 
MAX232 to generate the bias/contrast for the LCD. Plugging in the weather 
head should not affect it, but you may have a soldering error or something. 
Check the bias voltage before and after pligging in the head to see if this 
is the cause or a wild goose chase.

   It may be an obvious question, but just in case: You are plugging in the 
weather head into the "telephone" connector, not the serial port via the 
AAG-supplied adapter, right?

   Response from me is a bit slow as I'm out of the country and have only 
intermittent access to personal email and need a proxy to get info on the 
reflector. Thanks Russ!

   will
   ------Original Message------
   From: Mike C.
   Sender: wxsig-bounces at lists.tapr.org
   To: TAPR Weather Station SIG Mailing List
   ReplyTo: TAPR Weather Station SIG Mailing List
   Sent: Sep 16, 2006 9:50 PM
   Subject: [wxsig] T238+ Characters and Heat...

   Scott,

   Try adjusting the contrast potentiometer on the T238+ board. As you go
   through the adjustment range the blocks should become
   characters of info. As far as the 7805 5volt  1 amp regulator getting
   HOT. If you are running it on 13.8 vdc it will run hot.
   I had the same problem. I decided to run an 8 volt regulator 7808  in
   front of the 7805 to distribute the heat, between the two devices.

   Good Luck!

   Mike C.

   KA6DAC


   _______________________________________________
   wxsig mailing list
   wxsig at lists.tapr.org
   https://lists.tapr.org/cgi-bin/mailman/listinfo/wxsig



   -------
   Sent with thumbs on a PDA.
   Recycled electrons are 100% local content.

----- End forwarded message -----

_______________________________________________
wxsig mailing list
wxsig at lists.tapr.org
https://lists.tapr.org/cgi-bin/mailman/listinfo/wxsig






More information about the wxsig mailing list