Any solution for multiple input shear same pin?

Using Arduino Programming Questions
1

Hi,
If I have 3 sensors need input to the same pin say A3, are there any other solution better than a rotary switch?
Thanks for help.
Adam

2

Which pin of which sensors are you sharing? Your answer depends on what specifically you are trying to hook up.
There are I2c port expanders, there are multiplexers, SPI just requires another slave.
A better description will get you a better answer.

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3

Also there are analog multiplexers for analog signals. But they need 3 or 4 pins for channel select.

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4

Thanks.
Firstly the total 16 analog pins is not enough for my design, may be a clumsy design.
secondly the sensors use nothing special, just like: temperature sensor, GAS sensor, and even blood pressure kind.

5

Thanks.

6

The 74HC4067 chip will let you connect any of 16 analog inputs to a single analog input pin. You need 4 digital pins to select the input channel.

The SparkFun Mux Shield II will let you use 48 analog inputs.

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7

This is still an

insufficient description

because all these sensors are available with

  • analog output
  • digital output based on I2C.bus
  • digital output based on SPI-bus
  • some sensors have a digital output based on the onewire-bus

For example I2C enables to have (theoretically 127) sensors connected to just 2 IO-pins

So it really depends on a more detailed description

You seem to have not thought about required resolution and precision of your sensors
which is also important. And to get really good advice best thing to do is

speeding up finishing your project and do yourself a favor by reading
How to get the best out of this forum
best regards Stefan

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8

Hi,
Can you tell us the scope of your project please?
What model Arduino are you using?

Thanks.. Tom... :smiley: :+1: :coffee: :australia:

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9

Thank you.

10

Thank you.
I learn it.

11

Thanks.
just a multiple unit monitor in planning stage yet.
BTW. what's the solution to monit the different unit polling and view specific unit manually?

12

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