Step-down converter connected to Arduino

Using Arduino General Electronics
#1

I have to connect an Arduino mega to a PLC, and I will need the Arduino to run a sketch once it received a high signal from the Arduino. I am currently testing it on an UNO. I am just a little unsure of how to connect the step-down converter. Here is a link to the converter: https://www.amazon.com/gp/product/B00BWLP88A/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Does anyone have any suggestions?

#2

Are you talking about powering the Arduino or just level shifting a signal? If just a signal use
a resistor divider.

If powering you won't need a 15W converter like that, there are cheaper options, checkout LM2596
converters on eBay for instance.

#3

MarkT:
level shifting a signal? If just a signal use a resistor divider.

Hi MarkT,

I have read in some articles that level shifting by a resistor divider is cheap but dirty. That means the signal will not be good and stable. How do you think?

#4

Depends on the resistor values and the capacitance behind the level shifter.
If you feed the output of the level shifter into a length of twisted/shielded wire, you might end up with a low-pass filter.
Leo..

#5

A resistor divider is cheap and not as dirty as a step-down converter by a long shot for logic signals....

#6