Connecting Stamp I/O pins

Bill Chennault

All--

How do·I connect a dedicated Stamp output pin to a dedicated Stamp input pin on another Stamp?·I want to·experiment with some VERY rudimentary communication among Stamps. I want a Stamp to do some work, then tell another Stamp the results. The results may be as simple as setting a pin to indicate the work has been performed, or setting a pin to indicate the work has been done followed by a byte representing the work done. (I only need to communicate a few inches; say from one BOE to another as closely as I can place them.)

It sounds simple. Is it?

Thanks.

--Bill
ps I am fairly certain that I have seen this discussed. But, my SEARCH revealed little.

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You are what you write.

Mike Green

Theoretically, you could just connect the two pins together assuming that the two Stamps have a common ground connection. In practice, you should use a current limiting resistor to connect the pins, anywhere from 220 ohms to 10K in value, just in case you have a programming error and the two pins both get set to output mode at opposite levels (one low and one high) which would cause a short circuit and possibly burn out one or both I/O pins.

Bill Chennault

Mike--

Does the current limiting resistor simply connect the two pins? (Forgive my ignorance.)

Thanks!

--Bill

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You are what you write.

allanlane5

Yup, the 220 ohm current limiting resistor has one end connected to one BS2, and the other end connected to the pin on the other BS2.

Bill Chennault

allanlane5--

Thank you so much!

--Bill



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You are what you write.

LSB

Bill--

http://www.parallax.com/dl/docs/cols/nv/vol1/col/nv16.pdf·is a primer on serial communications and seems like it may be of help.

Bill Chennault

LSB--

Thank you! I saved it on my machine!

--Bill

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You are what you write.