Wired tilt control for Boe Bot (BS2)

gennarobasso81

Re: A Tilt Radio Controller for Your Boe-Bot

Hello everyone, This is my first time writing in a forum. I am still pretty new to the world of electronics but am learning a lot thanks to Parallax. I was hoping either a staff/admin/mod or a forum user could expand on the wiring diagram. It seems pretty basic i was just woundering where i would have to connect the pull-down resistor. I am assuming that the 220 goes from p10 to p11 signal I/O.

Thank you and sorry if this is a bit basic
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Mike Green

As you thought, the 220 Ohm resistor goes between one Stamp I/O pin and the other Stamp I/O pin. It's mostly there to protect against damage from programming errors. If you accidentally program one Stamp I/O pin to output high and the other to output low, you'd have a short circuit between the +5V supply (high) and ground (low). That will damage the I/O pin internal circuitry. The 220 Ohm resistor limits the current between the two I/O pins to something the I/O pin circuitry can handle.

The 10K pull-down goes from one I/O pin (either one ... but usually the receiving end) to ground (Vss). It sets the default I/O pin input status when the other I/O pin is also in input mode. When both I/O pins are in input mode, they're very sensitive to local electrical fields (static electricity and power line).

gennarobasso81

Thank you for your response.

Just fyi...if anyone views this thread and is fairly new to electronics, you might be interested in googling Pull down resistors and look for the texas intitiutes search results. Has a great document on pull up and pull down resistors.


Thanks again for your help