Crazy Problem....

Exilict

Ok, this is a new one..· As soon as I unplug the homework board from the computer the program no longer works...·· hook it up, it works again, unhook it.. nothing...

I use no computer interaction...

-X

biggin205

the only thing i can think of is that maybe the memory isnt working right

RickB

Is the program not running or is the board dead? Perhaps an open ground wire from your power supply is the culprit and the computer cable provides an alternate ground path for the board.

Rick

Exilict

nope... everything works fine execpt it wont read in a micro switch when i unplug the serial cable..

-X

dandreae

Hello,

Make sure that the green LED is still lit up, and make sure that you are unplugging the serial cable from the HomeWork board and not the laptop.· Sometimes a serial cable can act as an antenna and reset the stamp on the·ATN line.

Dave

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Dave Andreae

Tech Support
dandreae@parallax.com
www.parallax.com

·

Bruce Bates

Exlicit -

What type of micro-switch are you using - normally open or normally closed?

How is the micro-switch wired, both from source of power and to the Stamp?

Is there anything else in that curcuit besides the micro-switch?

What is the source of power, and what it the voltage at the source? Is this project wired on a breadboard?

What indication (if any) do you have that Stamp is operating at all? Do you have some audio, visual, or other indication such as a DEBUG statement to show that the Stamp is actually operating? If you have no DEBUG statement at the beginning of the program, you may want to add one that just says DEBUG "Starting" to make sure that it is starting and only starting once; thus not being reset inadvertantly.

As noted by others this is often a matter of either a missing ground, lack of a single common ground, or a source of power which is not what you expect it to be.

Regards,

Bruce Bates

steve_b

Could you have one of those debug statements in your program that is waiting on an input from a user?

Doesn't the serial cable provide for the echo back on the stamp?· so if he was waiting on a 'user input' then the echo back might do that and allow his program to run??

Just'a thinkin!

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Steve
http://members.rogers.com/steve.brady
http://www.geocities.com/paulsopenstage

"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."

Exilict

Ok....

The micro switch is powered and grounded by the stamp, however the switch goes to a different chip.
The reason I know it is working is because:
1 it works if I have it hooked up to my computer
2 it works if I even hook up the COM ground of my multimeter to the ground on the battery....


Any ideas?

-X

steve_b

Something cross wired??

Got a schematic?



Get rid of all the components and just try running the stamp with a simple program....the "Hello World" one is simple enough (it's in the manual!).

Then connect an LED thru a resistor to the stamp and ground and see if you can make it blink. (with or without the comm cable connected...shouldn't matter).



You may have noise on your board that gets sinked away when you connect an external ground.· And this is on a battery?· You doing this near motors or under flourescents?· How is the life of the battery?·

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Steve
http://members.rogers.com/steve.brady
http://www.geocities.com/paulsopenstage

"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."