RESet Question

Bill Chennault

All--

I would like for my BS2p40 "master" to reset four OEM BS2 "slaves." Ideally, the BS2p40 would use one pin to reset all four slaves at the same time. Is this possible? Can I tie a BS2p40·output pin to the RESet pin on an OEM BS2 through, perhaps, a·1 megaohm resistor* (I'm never sure!) and when I want the master to reset the slaves, execute a LOW n (where n is the output pin I've selected on the BS2p40)? If this is correct, could I tie that same BS2p40 output pin to all four of the OEM BS2 slaves and reset them all at once? Assuming I am on the right track, should I initially set the BS2p40 output pin I've selected for this function as input to keep it from accidentally resetting the slaves serendipitously?

Or, I am I totally off in the wilderness here?

Thanks and Merry Christmas!

*I am successfully using 1 megaohm resistors between the master and the four slaves in my unconventional pin to pin big-signaling scheme, which is working out pretty good, so far.

--Bill

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You are what you write.

Mike Green

The BS2p40 pins are initially set to input mode so that's where you should start. Read the description of the RES pin in the Parallax Basic Manual. 1 megohm is probably too large because the RES pin has its own pullup. Try a 1K resistor from one BS2p40 I/O pin to each of the slave BS2's RES pins. When you do a LOW, it'll reset the slaves, then do an INPUT to let the slaves go do their things.

Bill Chennault

Mike--

Thanks. Of course, I looked in all my Stamp manuals and found the most about RESet in Parallax's Basic Syntax and Reference manual. The trouble is, I could not extrapolate their wording to what I wanted to do, but did get the strong opinion that I might be on the right track.

Merry Christmas!

--Bill

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You are what you write.

Chris Savage

Bill,

To reset a BASIC Stamp via an I/O pin you would make the output of the pin LOW at the moment you want to initiate a reset. The line should then be made an input again, not brought high. Take care.

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Chris Savage
Parallax Tech Support

Bill Chennault

Chris--
· That's my plan!
· Hey! Don't you get at least ONE day off?
--Bill

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You are what you write.

Chris Savage

Bill,

Sure I do…I spread myself out a little so that our customers don’t go the whole weekend waiting for support from us. Let us know how you reset system/circuit works. Take care.

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Chris Savage
Parallax Tech Support

Tracy Allen

Hi Bill,

The ATN input may be available on your OEM stamps as well, I think. It is the pin that normally connects the DTR on the serial port and it resets the stamp when it pulses High. You could connect the '2p output to that via a 1k resistor.

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Tracy Allen
www.emesystems.com