In SX Microcontrollers, SX/B Compiler and SX-Key Tool, robotworkshop wrote:

According to your schematic you have the same +12V source powering some other things.  You don't list part #'s so we don't know exactly what those are.  When you are powering the circuit at 9V are the rest of them powered by 9V too??

How do you know the SX28 chip isn't running????  Are you basing that on the rest of your circuit???

Try connecting an LED (with current limiting resistor) to one of the other unused pins (you have plenty of them available) and add code to toggle it on and off at certain points in your program.  You can even add a few of them of you want to monitor several things.  That way you can use those to tell if the chip is running.  It might be running fine but you just might not be getting the output you expect because the rest of your circuit.

It is a good practice to use a 10K pull-up resistor on the /MCLR line so I would keep that there.  I always install one and you should leave it in place.

Your comment "but it is a high end Hewlett Packard" is a dangerous one.  By saying that it sounds like you've made assumptions that it must be fine and as a result may ignore the possibility that may be the problem and looking elsewhere.  To really troubleshoot things NEVER assume anything is good unless you test it and verify it is ok.  The things people immediately rule out are often ones that can be the problem.

What kind of Hewlett Packard power supply is it?  Would this be a switching style power supply??  Some of those won't work properly unless there is a load on them.  Your circuit shouldn't take much power at all and for some switching supplies it may not be enough of a load.

Just a few more things to look at.

Robert

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=435144#m435569

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2010 (http://www.dotNetBB.com)