Re: Rotational Encoders


"Bob Myers" <nospamplease@xxxxxxxxxxxxxxx> wrote in message
news:PZBnh.4018$vr2.3997@xxxxxxxxxxxxxxxxxxx

"Michael" <mqiqcqhqaqeqlqhqiqm@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in
message news:n2Bnh.26228$k74.7654@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I presumed that as I moved the ball the orange and yellow wires would go
low (they're high when 5V is applied to the power wires) however
connecting it up to a darlington array driving a LED doesn't seem to
affect the brightness at all(I realise this is a crude way but it's all I
had available at the time)

Have you looked at these lines on a scope, or just put
a meter on them? The way most rotational encoders work
is by putting out a pair of pulse trains or "square-wave"-
looking signals, and you watch the phase relation between
the two and count the number of pulses to figure out
how far the thing has moved and in which direction. A
simple meter might easily read these lines as a steady
5V or thereabouts, and you wouldn't necessarily see
anything on an LED, either (the pulses are too fast, if
you're moving at anything like normal speeds).

Bob M.


I havn't got a scope to hand. However the meter stays at 5V (or
thereabouts). I havn't yet seen it change when the ball is moved.

Surely there must be a point where you can leave it and it stays low as
light is being blocked/let through?

Michael


.

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