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### Topic: on/off switches in resistor voltage divider (Read 12536 times)previous topic - next topic

#### fungus

#15
##### Jun 18, 2014, 08:43 am

Yes, a great idea.
Digital ---> analog ---> digital

The idea is that the path is narrower in the middle....

#### fungus

#16
##### Jun 18, 2014, 08:45 amLast Edit: Jun 18, 2014, 08:53 am by fungus Reason: 1

If I am using each pins; that would be need maybe 400 pins,
...
I need double values.

This is unlikely to work.

It might sound good in theory, but ...

Why don't you tell us what you're trying to make/achieve, not what you're doing. That way nobody will waste any time giving non-applicable answers.

#### Grumpy_Mike

#17
##### Jun 18, 2014, 10:56 am
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that would be need maybe 400 pins

That implies you need a 20 by 20 matrix of switches.

#### fungus

#18
##### Jun 18, 2014, 11:12 amLast Edit: Jun 18, 2014, 11:17 am by fungus Reason: 1

Quote
that would be need maybe 400 pins

That implies you need a 20 by 20 matrix of switches.

I spotted that, too!

Sounds to me like somebody's trying to make a MIDI controller (or something similar).

#### vffgaston

#19
##### Jun 18, 2014, 12:27 pm
What are you trying to do?

#### Qwseyvnd

#20
##### Jun 19, 2014, 04:56 pmLast Edit: Jun 19, 2014, 05:12 pm by Qwseyvnd Reason: 1
See this image:
http://www.airliners.net/photo/Aeroflot/Ilyushin-Il-62/1084219/L/&sid=88b5aa0092f257b39b8336e8d937c49c
Is that possible: Detect which switch toggle switch are used in one pin?

It is possible through this guide:
http://arduino.cc/en/Tutorial/TwoSwitchesOnePin

So, therefore, I wonder if it is possible with three and more switches ?

#### Grumpy_Mike

#21
##### Jun 19, 2014, 05:08 pm

See this image:
http://www.airliners.net/photo/Aeroflot/Ilyushin-Il-62/1084219/L/&sid=88b5aa0092f257b39b8336e8d937c49c
Is that possible: Detect which switch toggle switch are used in one pin?

No way on God's Earth is it possible to read all those switches with one pin.

Two pins an a bunch of shift registers yes but one pin no.

#### Qwseyvnd

#22
##### Jun 19, 2014, 05:13 pm

See this image:
http://www.airliners.net/photo/Aeroflot/Ilyushin-Il-62/1084219/L/&sid=88b5aa0092f257b39b8336e8d937c49c
Is that possible: Detect which switch toggle switch are used in one pin?

No way on God's Earth is it possible to read all those switches with one pin.

Two pins an a bunch of shift registers yes but one pin no.

You said no? See here: http://arduino.cc/en/Tutorial/TwoSwitchesOnePin
It's possible. So, I wondering if it is possible with three and more.

#### Grumpy_Mike

#23
##### Jun 19, 2014, 05:17 pm
If you understood how that technique worked you would know you can not do it with more than two switches. Certainly not 400.

#24
OK.

#### fungus

#25
##### Jun 19, 2014, 06:12 pm
You still haven't told us what you're trying to do.

I know how to read hundreds of switches using only two Arduino pins but I'm not going to waste time explaining the method unless I'm sure it works the way you need.

#### vffgaston

#26
##### Jun 19, 2014, 06:59 pm
Quote
You still haven't told us what you're trying to do.

I know how to read hundreds of switches using only two Arduino pins but I'm not going to waste time explaining the method unless I'm sure it works the way you need.

There is a (very old) method (in fact is a primitive DAC) to "read" many switches in an analog input. May be this is what this man (this pollo; I would say) is looking for.

(I adjoint a page of my -very old- Millman)

#### Grumpy_Mike

#27
##### Jun 19, 2014, 10:56 pm
Quote

You can't read more switches than you have bits in the A/D converter, possibly two less, with multiple switch contacts!

This guy wants to read 400 switches!

#### vffgaston

#28
##### Jun 20, 2014, 11:42 am
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You can't read more switches than you have bits in the A/D converter, possibly two less, with multiple switch contacts!

This guy wants to read 400 switches!

Absolutelly. I just tried lo give some ligth on the subject.

Regards.

#29

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