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I am using Arduino UNO board. I have 24 analog channel which gives me 0~5v analog out put. Now my problem is I have only 5 analog channel. I wanted to read value from each channel for every 2 min and then switch to other channel. Can anyone suggest me in Hardware how can get analog value ?

I am planning to use 8:1 multiplexer or 16:1 multiplexer . Will it is correct way of doing it. Can you suggest other way of doing it in hardware ?

74HC4051,74HCT4051,ADG708,MD14051B, IC I am planning to Use.dep[end on so,s1,s2 just switch the channel

10 Rep
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AMPS
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As a start, you might need to know that even Arduino Uno also have internal MUX. In my experience of reading multiple analog channel, this is the approach that I take. However by taking this approach, I suggest you to recheck the analog value so adding MUX will not generate any error or bias.

This could be done by comparing the output of measurement with the MUX and output of measurement without the MUX. I used 74HC4051 and it works brilliantly, just make sure not to leave any pin floating. The only disadvantage of this method is that you will need to use some I/O to control the MUX, but if that is not an issue for you, then go ahead.

Any other method could be more complicated. It would require your analog channels to correlate with each other, and you need to find a way method to combine multiple analog channel into a single channel.

e.g: if your aim is to compare two analog value, instead of measuring the value and comparing the value in software, you could make use of op-amp comparison circuit to compare the value for you and take the comparison result instead.

Setra Yoman
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Use the photon-pixel coupling method, it is a new approach in science for sampling an unlimited number of sensors in parallel.

Basically, each sensor output is an LED. If you have 10000 sensors, the output of all of them is inserted in a LED array, a LED matrix as the authors say. After that, the LED array is filmed by a video camera and the images are processed in real time by a computer. A software reads one pixel from each LED from the LED array and converts it to numerical values. So, your LED array will be converted in a matrix (with 10000 elements) filled with numbers that can be processed as you wish in your software. I don't know if I was explicit but you can read their article here: https://www.sciencedirect.com/science/article/pii/S2215016119300901

Note that classic multiplexing is serial, this approach is parallel.

Schematics of the Photon-pixel coupling from the original article

The photon-pixel coupling method is truly ingenious because it solves two main problems in engineering: an unlimited number of sensors and their parallel sampling at video rate frequencies. Just imagine, we can read as many sensors as we wish. What I wander is if we can adapt the photon-pixel coupling to Arduino. I am new in the world of microcontrollers but I know Arduino can support a cam, so it should be possible.

If you are a PhD student then: P.A. Gagniuc, C. Ionescu-Tirgoviste, R.G. Serban, E. Gagniuc. Photon-pixel coupling: A method for parallel acquisition of electrical signals in scientific investigations. MethodsX, 6:968-979, 2019.

MeMa
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To read more analog channels than inputs you have, an analog multiplexer is a good option. All the ones you suggested will work, but personally, I like the Analog Devices ICs for analog circuits, so I would take the ADG708, but this is just a personal preference.

ferrangb
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  • You could build your own analog circuit with transistors, or even use relays if you want, but an analog multiplexer is the most efficient, easy and elegant way to do it. – ferrangb Sep 12 '14 at 08:09