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Unread 02-04-2008, 09:44
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Re: IR Board Programming/Wiring Problems

Quote:
Originally Posted by Ryan O View Post
According to the manual, and tests with microswitches, the input default high, aka backwards from normal
I'm not sure what you mean by this.

A digital input on the RC will be read as a high value, a logic 1, when there is nothing connected to it. An open switch gives a lack of continuity, which is electrically the same thing as nothing. A contact closure to ground will be read as a low value, a logic 0. That's "normal" for the digital inputs.

The IR sensor board outputs are not like switches. They are actual logic levels. When an output's associated LED is off, the output is at logic 0. When an output's associated LED is on, the output is at logic 1. That's "normal" for a TTL signal.

When you connect the IR board outputs to the RC digital inputs, the values do not somehow change to being "backwards". An inactive signal is still 0, and an active signal is still 1.