BOE Jumpper between X4 and X5

Acadian

Just wondering what· the jumper that is sitting between X4 and X5 on the BOE?

Someone in my class thought that it might change Vin to additional VDD.


Just another question. Why is VIN connected on the same line as VSS and VDD?··4·of my classmates have destroyed their BS2 IC by accidently connecting a button to Vin instead of VSS, because they are so close together.

·

Chris Savage

That jumper selects whether the X4 and X5 jacks get their power from Vin or Vdd.· The Vin is whatever voltage is coming into the BOE via the Battery Connector, or the DC Input Jack.· If you're using a battery this would be 9VDC.· If you're using the DC Jack, it would be the voltage of your Wall-Wart or other Power source.· When the jumper is switched to Vdd, then the X4 and X5 jacks get their power from the BOE's 5 VDC regulator.

As for your other question, it makes sense to have the power connection available relatively close to the breadboard.· The Stamp I/O pins take up one side, and two sides are at the edge of the board, so that leaves the strip where the 3 power busses connect.

You should always check your wiring carefully before applying power.· Students should probably have their classroom instructor double-check their work before applying power.· That would help avoid anymore burnt BS2s.



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Chris Savage

Knight Designs
324 West Main Street
P.O. Box 97
Montour Falls, NY 14865
(607) 535-6777

Business Page:·· http://www.knightdesigns.com
Personal Page:··· http://www.lightlink.com/dream/chris
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·

Ken Gracey

As for the classmates who detonated four BASIC Stamps, tell the instructor to call for an RMA number and we can replace them.

Ken Gracey
Parallax, Inc.