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Topic: Multiplex IR LED's? (Read 7 times) previous topic - next topic

xXN1pplefaceXx

Can we do the same technique used in say this: http://www.youtube.com/watch?v=-1UPPHjR0vk&feature=player_embedded, but instead with IR emitters and detectors?

Grumpy_Mike

Well the title of the post is a bit wrong if you want to multiplex detectors. The principle is the same but the circuit is different. And you will only look at one detector at a time, so it will be no good for IR data like from a remote.

xXN1pplefaceXx


Well the title of the post is a bit wrong if you want to multiplex detectors. The principle is the same but the circuit is different. And you will only look at one detector at a time, so it will be no good for IR data like from a remote.

Thats fine :), Im just looking to detect IR light emitting from the emitters not any data. Also could you please show me an example, it would be much appreciated :)?

Grumpy_Mike

This is an example of multiplexing many analogue inputs into the arduino:-
http://www.thebox.myzen.co.uk/Hardware/MIDI_Footsteps.html

xXN1pplefaceXx


This is an example of multiplexing many analogue inputs into the arduino:-
http://www.thebox.myzen.co.uk/Hardware/MIDI_Footsteps.html


Ok after reading that page I think I understand what to do, but am still confused. So I have questions regarding that:

  • Are you suggesting I use a 4051 and loop through all the sensor readings? After reading this: http://www.arduino.cc/playground/Learning/4051 I feel it is probably a good idea

  • I never even new these extenders existed until now, so looking back on this: http://arduino.cc/forum/index.php/topic,98317.0.html Would it be suitable to use 2 4051's to control an 8x8 matrix of LED's or maybe even 2 4067's and I could have a 8x12 Matrix? :P

  • Would these be suitable or fast enough to switch (I know the photodiodes probably dont but the LED's from the prev question do), I really dont know how to read the datasheet :(

  • To my understanding, all I need to control these are 3 pins on the 4051s and 4 on the 4067s?

  • In your footsteps example, You have 3 pins on the 4051 going to ground, and 1 to the analog input, If I were to not use it as an input and rather an output, how would I do it? I have searched it and only found examples with confusing diagrams

  • I havnt been able to find many 4067s are there any other 16 channel multiplexers that are similar

  • If I have 3 4067s for a 8x12 matrix of LED's and 1 row of 12 photodiodes and 4 blank inputs reading on 1 input to the arduino, that uses 1 Analog in and only 12 Digital Pins right?

  • Last but not least, How do I incorporate the emitters then? Do I just hook them up in parralel with the arduino to the 12v adapter (making sure I lower their voltages) and then control them with a transistor or a simple relay to turn them on and off so theres no power wasted?


I also found this which is helpful if anyone else is reading this that has the same low knowledge as me :P http://colab.lcc.gatech.edu/wp-content/uploads/2012/04/Analog-Mux-4051.pdf

You are the best and a genius if you can even answer one of these questions ;)
Also That is a great link btw it is very helpful it opened me up to so many possiblities, Thankyou so much grumpy_mike XD XD XD XD XD XD XD XD XD XD

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