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I have 256 analog sensors that have VDD (5V), GND, OUT ( analog output that goes to A0 of my arduino uno).

i was hopping to controll them by turning them on or off individualy and take readings in A0 that they all connect. To do so i was thinking of connecting their suplly to a matrix and control the matrix with 2 16:1 multiplexers. and now my question is :

  1. A CD74HM4067M multiplexer has a common pin. i will provide the 5v by conecting it to a digital pin on my arduino and setting it to HIGH. When i change my multiplexer to go to 2nd channel of the 16 the rest of the channels will stay at their previus condition or will the go Low?

  2. If this is the case how do i operate tha GND MUX ? should i use transistors to triger with my Multiplexer in order to connect the right gnd collumn to GND ?

  3. if so , should i do the same with the 5v rows as well ?

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  • \$\begingroup\$ What are your sensors? If they are semiconductor, they might not work as you’d like in the matrix due to backfeeding through intrinsic diodes. \$\endgroup\$ – Kartman 2 days ago
  • \$\begingroup\$ Tell us more: What's the poll rate? That number divided by 256 will tell us how much time you're allowing for the circuit to work. What's the current the sensor can provide? What's the turn-on time for the sensors? If it's large, you might consider leaving all the sensors on the whole time. How long are the sensor wires? Capacitors take time to charge, especially if the supply (your sensor) is weak. How much signal noise can you tolerate? The faster the poll rate, the less time there is to get the signal from the sensor to be stable, going through the ADC. \$\endgroup\$ – Schuyler Horky yesterday

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