12 volt dc to arduino input

Using Arduino Project Guidance
1

Hi,
I got 12 relays that control 12 devices with 12v dc

I want to sense the current or if that devices working (but not with the relays output pins as i want to add manual switches)

-How to get this 12v to be a signal for the arduino to work as input high and low, also is this approach better or just put a voltage sensor or currwnt sensor whatever

2

I don't fully understand what you want to achieve. Can you maybe draw a schematic?

If you just want to use a 12V signal as an digital input to your arduino, make a voltage divider.

3

TimMJN:
I don't fully understand what you want to achieve. Can you maybe draw a schematic?

If you just want to use a 12V signal as an digital input to your arduino, make a voltage divider.

the goal is to get the state of each device from the 12 devices if it is on or off.

could you support me with the schematic of the voltage divider, also will the 5v output will be readable with no issue in the arduino pins or will i need and convertong or whatever

4

KareemWaheed:
Hi,
I got 12 relays that control 12 devices with 12v dc

I want to sense the current or if that devices working (but not with the relays output pins as i want to add manual switches)

-How to get this 12v to be a signal for the arduino to work as input high and low, also is this approach better or just put a voltage sensor or currwnt sensor whatever

I suggest you google "voltage divider" yourself and learn something in the process. Once you come up with a schematic, we can have a look at it.

5

Input02.png

6

Paul__B:
Input02.png

i think you meant R2 33K resistor, right?

but please i'm new to the field could you support with these:

  • are the diodes mandatory in the circute?
  • the input 5v volt pin it will go to the analog input in Arduino right?
  • if there is N devices, i'll make N circuit right, there is no simple way to modify the circuit to be able to handle lets say (12 devices)

Thanks for the support

7

At 12 V, the circuit will deliver 3.6 V to the Arduino pin which is a clean HIGH. This circuit is principally for automotive use where the voltage input may routinely be as high as 14 or even 15 V.

You could use a 33k in any case because the diodes strictly prevent the Arduino pin seeing any more than the 5 V Vcc given that the absolute limit is specified as Vcc + 0.5 V - or any negative voltage. That is precisely what the diodes are for. :grinning: