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Topic: Reading 10+ LDR with Arduino (Read 1 time) previous topic - next topic

xkishorx

Hey Folks,

I am brainstorming for a project that I am about to do, and It would need me to read 10+ LDRs. As There arent that many analogue input pins, whats the workaround that I can put to use? :(

Thanks  :)

AWOL

"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

xkishorx


Use a Mega


I am assuming there is a workaround than buying another Arduino.  :~

AlxDroidDev


Use a Mega


Too expensive, and the guy already has an Arduino (not Mega, I suppose)

My suggestion is to use a multiplexer IC, like the CD4051.

Personally, I like and use the MAX4617 (datasheet)
Learn to live: Live to learn.
Showing off my work: http://arduino.cc/forum/index.php/topic,126197.0.html

AWOL

External analogue muxes, like a couple of 4051.

Quote
Too expensive, and the guy already has an Arduino

He never stated that.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

xkishorx

Quote
As There arent that many analogue input pins


By that, I meant I had an Arduino. Sorry for not making it clear. I have an Arduino UNO R3.

So a multiplexer is what I should use?

Since I am new to all these, can someone give me a little insight? a circuit diagram or something so?

Cheers! :)

AWOL

http://playground.arduino.cc/learning/4051
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

Lakes

Is this for a (low res) vision sensor?

I remember seeing something like that on BBC Click that controlled an array of mirrors (I think)

xkishorx


http://playground.arduino.cc/learning/4051

Seems like this is what I am looking for :D

Can I breadboard it? or it should be bought as a chip? (For both saving money and for satisfaction of doing it.)

MikMo

You can breadboard it with just the chip.

The CD4067 has 16 "inputs" if you need more than 8

xkishorx

#10
Apr 03, 2013, 08:05 pm Last Edit: Apr 03, 2013, 08:08 pm by xkishorx Reason: 1

You can breadboard it with just the chip.

The CD4067 has 16 "inputs" if you need more than 8


8 would be fine, 16 would be better if there isnt much price difference with the chip.

Sorry for asking this, but I will appreciate a right circuit diagram for bread boarding it, because I am new to this. I tend to make mistakes when it comes to where I should be applying the voltage and so. (Happened before :D )

Thanks a lot :)


ADD : Or the 4051 would be fine because after a bit of reading, I see the 16 inputs one needs 4 pins from my arduino.

AlxDroidDev


ADD : Or the 4051 would be fine because after a bit of reading, I see the 16 inputs one needs 4 pins from my arduino.


of the 4 pins required, 3 of them are digital pins, OUTPUT, used to select which input in the 4051 (or 4050) is to be read. The other pin is one of the Analog inputs of the arduino that will receive the output of the 4051 for its selected input.
Learn to live: Live to learn.
Showing off my work: http://arduino.cc/forum/index.php/topic,126197.0.html

xkishorx



ADD : Or the 4051 would be fine because after a bit of reading, I see the 16 inputs one needs 4 pins from my arduino.


of the 4 pins required, 3 of them are digital pins, OUTPUT, used to select which input in the 4051 (or 4050) is to be read. The other pin is one of the Analog inputs of the arduino that will receive the output of the 4051 for its selected input.



I have bit of an understanding about Multiplexer now, but I thought that was 4 output Pins and another 1 analogue pin. For my project, I can give 3 Output pins for this. Yeah, thats fine. Looking forward for a clear circuit diagram if one is available :)

AWOL

For two muxes, you'll need four digital outputs and two analogue inputs.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

xkishorx


For two muxes, you'll need four digital outputs and two analogue inputs.


Point taken.

But I am looking for 1 Input instead of 2. Do I still need 4 digital outputs? Well, but the other member here said they are 3 outputs and 1 input.


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