Fan RPM detection issue

You have a stepdown converter just to provide a bias voltage for the potentiometer? Also why 5.1V and not 5.0V?

I am powering the Arduino with it as well. When I was using the Every, I had problems with the display if the voltage was different so I have kept it like that. I had the same issue with the display while coming to Vin, dont know why, therefore I have used the step down and solved it like this. Maybe with the Nano classic it would be different but I had this already in place and thus only changed the Arduino from the shield,

br. Tomas

Then the schematic has an omission. Don't feed the Nano from the USB jack, it has a diode which drops voltage to the board - not ideal. Run the step down output directly to the 5V pin of the Nano.

Also - isn't your display a 3.3V device? You should have voltage level converters on all the digital lines to the display.

Will keep this in mind for the next project, still learning here and since all is already on the board. I would keep it like it is for now.

As for the display, according to the description from the CN shop, the input is 3.3V, however, every other pin should accept 3.3-5V. During the assembly I added some simple voltage dividers to the board, but the display wasnt working although the dividers were working and thus I disabled them at the end.

add: the reviews for the display were very bad though, I will next time buy something more reliable :slight_smile:

By "input", do you mean power supply?

Should accept 3.3V-5V according to what source of information? The Adafruit board purports to have level shifters built in, I have no idea if the Chinese clone also has them...

The thread has wandered somewhat off topic, is everything working now?

Hi, yes, everything works now. The issue was caused by the 100nf cap, lowering it to 33pf solved the issue.

Tomas