Re: Ultrasonic sensor interactions

"Philippe Hurbain" <[email protected]> Mon, 22 May 2006 07:23:42 GMT
Newsgroups gmane.comp.hardware.lego.robotics
Organization None
Message-ID <[email protected]>
>    I'm not positive of that. If the US sensor is plugged in to a powered NXT, I
> can detect a clicking from it - I presume it's on. Regardless of what sensor I
> define the port as, this clicking continues. This is what I was basing my "can't
> turn the US sensor off" remark on.

Sorry Brian, you are right! my ageing ear was not able to get the much weaker
"ping" at first. My interpretation (to be confimed) is that the US sensor goes
on working even if not configured, but some sensor modes don't provide the 9V
supply that powers US transducers. So they are working from the much weaker,
high impedance 5V and the ping is greately attenuated.

Strangely enough, using the touch sensor as alternate sensor, the ping is not
diminished, implying that 9V is present in that mode (though on RCX it is a
passive, non powered sensor). I have to check that!

>
>> At low level sample rate can be changed - and even a single
>> shot mode is available - but presently NXT-G doesn't give
>> access to these features
>
>    Have you been able to verify this? I know there are FW commands that claim to
> do this, but I've not seen it provably done as yet. And would *love* to hear
> it's possible.
>
Yes, that's theoretical, I have yet to do detailed testing. Perhaps John Barnes
already did that?

Philo