Re: xPL-LCD PICS

["Frank Mc Alinden" <fmcalind@xxxxxxxxxxxxxx>]

Hi Dave

> I have to admit that the QT110 and QT115 that I used to use to control
> interactive exhibits 'hardly' ever false triggered once set up.

This could be my problem....not setup properly.....

> I also used to run the QT devices from a separate linear regulator IC
> and associated filter caps, a 1R resistor in series with the supply to
> the regulator could also help blocking noise by creating a slightly
> higher impedance path on the supply.

It was being powered by the pic icd so im assuming that would be pretty
clean....

> IIRC the cap should be matched to the capacitance of the sensor,  I
used
> to have a QT11x demo board (the one with the two AAA batteries)  and a
> range of caps that I used to determine the capacitance required for a
> particular sensor,  and a piece of SIL strip socket on the final
circuit
> to plug the caps into.

So how was it determined...??? I suppose i should have a real good read of
this qprox stuff....

> Could it be possible that the banana plug sensors are the 'wrong way
> around' for the QT to operate reliably?  I.e. the large area which
would
> be more sensitive to touch is inside your box
> It may be better to have a sensor that is wider than it is deep, for
> example's sake just use a washer with a wire connecting to the QT
device

Quite possible...but  im also using the banana plug as an led holder ....

> HTH and keep up the inspirational work ;)

Thanks for the feedback and pointers


>BTW I like the LCD where did it come from?   I was luck enough to be
> given an Airport Express for Christmas and I am trying to think of the
> neatest solution to control the iTunes server remotely

Got it here in Melbourne...PLED LCD  .......no backlit required.....

Whats a Airport Express...???

Frank


----- Original Message -----
From: "Ward, David" <DAvid.Ward@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Thursday, March 24, 2005 9:25 PM
Subject: RE: [ukha_d] xPL-LCD PICS


>
> Frank,
>
> Good idea, a software filter could help, ignoring nonsensical presses
> whilst in menus etc would also make it more robust.
> I have to admit that the QT110 and QT115 that I used to use to control
> interactive exhibits 'hardly' ever false triggered once set up.
>
> IIRC the cap should be matched to the capacitance of the sensor,  I
used
> to have a QT11x demo board (the one with the two AAA batteries)  and a
> range of caps that I used to determine the capacitance required for a
> particular sensor,  and a piece of SIL strip socket on the final
circuit
> to plug the caps into.
>
> I also used to run the QT devices from a separate linear regulator IC
> and associated filter caps, a 1R resistor in series with the supply to
> the regulator could also help blocking noise by creating a slightly
> higher impedance path on the supply.
>
> What QT device(s) are you using?
>
> Just had another though
> The QT devices operate by 'transferring charge' from the sense
capacitor
> to the in circuit capacitor - when the voltage on that cap reaches a
> threshold the output operates. The sense cap is formed between your
> finger and the sense plate.
>
> Could it be possible that the banana plug sensors are the 'wrong way
> around' for the QT to operate reliably?  I.e. the large area which
would
> be more sensitive to touch is inside your box
> It may be better to have a sensor that is wider than it is deep, for
> example's sake just use a washer with a wire connecting to the QT
device
>
> If I get a chance (and I can find them) I may have a play with the QT
> device I have around here somewhere
>
> HTH and keep up the inspirational work ;)
>
> Dave
>
> BTW I like the LCD where did it come from?   I was luck enough to be
> given an Airport Express for Christmas and I am trying to think of the
> neatest solution to control the iTunes server remotely
>
>
>
> -----Original Message-----
> From: Frank Mc Alinden [mailto:fmcalind@xxxxxxx]
> Sent: 24 March 2005 09:57
> To: ukha_d@xxxxxxx
> Subject: Re: [ukha_d] xPL-LCD PICS
>
>
> Hi David
>
> > Have you considered putting a washer around the socket?
> > It could go in front or behind the panel....
>
> Yep tried that yesterday , behind the panel didnt make any
> difference....I
> also changed the capacitor from 4n7 to 10nf...but it  started false
> triggering...?? generating heaps of xpl trig messages.....Are you
> suppose to
> debounce the qprox outputs ?? ..... i now have a 50msec debounce ....
>
> Frank
>
> ----- Original Message -----
> From: "Ward, David" <DAvid.Ward@xxxxxxx>
> To: <ukha_d@xxxxxxx>
> Sent: Thursday, March 24, 2005 8:48 PM
> Subject: RE: [ukha_d] xPL-LCD PICS
>
>
> >
> > Very nice Frank
> >
> > Have you considered putting a washer around the socket?
> > It could go in front or behind the panel....
> >
> > Dave
> >
> > -----Original Message-----
> > From: Frank Mc Alinden [mailto:fmcalind@xxxxxxx]
> > Sent: 24 March 2005 09:13
> > To: ukha_d@xxxxxxx
> > Subject: [ukha_d] xPL-LCD PICS
> >
> >
> > Hi All
> >         I have now put some pics on my website of the xPL-LCD 
....If
> > interested in having  a look..Follow the xPL ..link........
> > http://skybax.rapidhoster.co.uk/~armagh/index.html
> >
> >
> >
> > Frank
> > www.armaghelectrical.com.au
> >
> >
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> >
> >
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