Subject:
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Re: light sensor multiplexer
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Newsgroups:
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lugnet.robotics.rcx
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Date:
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Wed, 21 Mar 2001 13:07:51 GMT
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Viewed:
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1424 times
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Hi Rainer,
I do not understand quite your point about timing. Regarding to
power sharp takes much more than what your RCX can give ( my measuremants
show that RCX gives RMS current of )15 mA only this is not going to drive
your sharp at all.
Regarding timing you need one pulse to three pulses to chose and transfer
the sensor. once you have done it you can be there on that sensor as long as
you wish. ( it looks like to me that you have( or I have ) little
misunderstanding on what I(or you ) do.
Regarding Gasperis circuit. first of all it is NOT random selection of
sensors. and you need a referance channel. another in not very effecient in
power since it have lot of components. I have single microcontrolor running
at 4Mhz and if the power requirements are stringents I can run it at lower
speed to get it working at extremely low power.
any way.
thanks and regards
In lugnet.robotics.rcx, Rainer Balzerowski writes:
> In lugnet.robotics.rcx, Nitin Patil writes:
> > Hi Rainer
> >
> > What I do is that switch the power to silected sensor only I do it by using
> > FET. since there is not enough power for all sensors.
> > so when you switch to sensor 2 other sensors are kept off.
> > there is enough power for one sensor since my circuit takes only 500 microAmp.
> > which is around 4%of total power.
> > I have more details ( see in specification/ some no that can give you idea
> > of power) on www.geocities.com/mindsensors
> > and I am composing more on circuit to add. once that is done I will put it up
>
> Hi Nitin,
>
> okay, I see.
> Sorry, but then your circuit isn't interesting for me.
> I thought about using Sharp GP2D12 with it, but that won't work.
> First the Sharps have a current consumption of about 33mA up to 50mA max.
> Second the Sharps need (see Datasheet) 38,3ms +/- 9,6ms till first
> measurement plus 5ms from first measurement to first output. (worst case 52,9ms)
> -> 10ms + 30 ms + 50 ms + 3* 53ms = 249ms per cycle. -> 4 cycles per second
> when turning of the sharps between measurments :(
> That's why I'll prefer the solution of Michael Gasperi.
> (I build it, look here : http://www.informatik.fh-hamburg.de/~lego )
>
> Never the less it's a great work you offer.
>
> Rainer
>
> P.S.: I asked a friend of mine to layer and route the Gasperi circuit I
> introduced above with surface mounted devices. (maybe with 9 inputs) I'll
> post success here (will take some weeks (month ? years ? decades ?
> millenniums ?)). So perhaps a little series if someone interested ?!?
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Message has 2 Replies:
 | | Re: light sensor multiplexer
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| Hi Nitin, (...) Yes, sadly but true. That's why I have to use a battery anyway. (Or an output, but I would save it for other tasks.) (...) I understand. I should have explained what i'm doing with the sharps, sorry. I have a task running, that (...) (23 years ago, 21-Mar-01, to lugnet.robotics.rcx)
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Message is in Reply To:
| | Re: light sensor multiplexer
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| (...) Hi Nitin, okay, I see. Sorry, but then your circuit isn't interesting for me. I thought about using Sharp GP2D12 with it, but that won't work. First the Sharps have a current consumption of about 33mA up to 50mA max. Second the Sharps need (...) (23 years ago, 20-Mar-01, to lugnet.robotics.rcx)
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