Hi. I'm measuring the temperature from a device that outputs 0-5V. The intention is to use Nano 33 IoT version which uses 3.3V as input so I will need to shift down the voltage to do an analogRead.
I've google and found that people either use simples double resistor voltage dividers, or logic level shifter modules. Any idea which one would be more suitable for my use case and why?
Does your device send an analog or a digital signal?
If analog: resistor divider
If digital: is communication both ways?
If yes: level shifter.
If no: both will work.
This is not suitable for readings with an analogue to digital converter, as that is a digital shift not an analogue one. Use a potential divider.
Thanks very much for the quick replies. It is indeed a variable analog signal 0-5V so voltage divider it is.
Yep, that will work fine!
No.
You are trying to drive a motor, which by definition will take a lot of current, through a 10K load.
Potential dividers only work if the current being drawn through the two resistors is about ten times greater than the current through the resistor chain.
Yes a capacitor will reduce the noise from the motor but as you have it drawn in that diagram it will not work.
Where was the motor mentioned?
In the diagram in post #5
You seem to see more than me...
Is it perhaps it's the icon that's causing the confusion? I get the round icon when I press voltage source in LTSpice. In any case, I'm not driving anything with the circuit, simply reading a 0-5V out from a device
Maybe...
An arduino analog input is not a voltage source....
So the symbol there is not adequate.
Usually a standard dc motor has two squares on both sides. But there might be other symbols around..
In Europe a resistor is a rectangle in America it is a zigzag line. No problem as long as no one gets confused...
Good feedback. What would be the appropriate symbol for a device like arduino?
No idea... even google does not know...
Yes it is.
But that is for a simulator not for a schematic. Your mixing of the two worlds of schematic and simulator is what is causing the confusion.
Yes, but to my eye it looked more like a motor than anything else.
OK sorry for the misinterpretation, but in my defence I would say I was provoked. 
No excuses needed here! It is good we sorted out the somehow ambiguous signs!
All right. Thanks for the feedback. I find it to be a very nice to program to sketch in but I'll look around if I can find another option. Circuit lab free seems is quite restricted.
Which symbol would you use to indicate Arduino or any other microcontroller/device?
A box, with the word Arduino written in it. And the inputs/outputs labelled also. You don't have to include every input/output, just the ones being used in the circuit (including power and ground).
Pencil and paper? Quite acceptable for simpler diagrams, provided it's reasonably neatly drawn. Squared paper helps, if you have some.
This is an example of a simple diagram that shows you how to get sound into an Arduino:-
I have a follow-up question on the initial one.
I'll have to switch to Esp32. After googling around some more I found that some people recommended using a separate ADC since the one in Esp32 doesn't have good resolution. ADS1115 seems like a good option.
Do you think the following setup will work? I'm particularly unsure about the red-coloured Esp32/device-common ground. Would this be the correct way to do it, or should I omit the ground from the Esp to the device?
EDIT: R2 should be 20k
