PulseIn problem

Hi guys,

First of all thanks for your time. So my problem is I am trying to send a Pulse signal from a Nano to Uno to make sure am sending the right pulse.

When I connect my Uno to the usb and supply from it everything works fine and I get as expected result. As soon as I attach the nano to another supply and leave the uno on usb to use the Serial Monitor I get extra (unwanted) values with my pulse. I also noticed that if I disconnect everything I get a 0.. which is normal.. as soon as I put in a wire on the pin(which on the other end is connected to nothing) I also get the strange values.

Any ideas please?

thanks in advance

Post your code
Post a picture of your setup
Post your errors

I would like not to make assumptions about your problem to find out I am wrong

Razgrizzz:
When I connect my Uno to the usb and supply from it everything works fine and I get as expected result. As soon as I attach the nano to another supply and leave the uno on usb to use the Serial Monitor I get extra (unwanted) values with my pulse.

Sounds like the UNO ground and Nano grounds are not connected. They should be.

Razgrizzz:
I also noticed that if I disconnect everything I get a 0.. which is normal.. as soon as I put in a wire on the pin(which on the other end is connected to nothing) I also get the strange values.

It is not 'normal' to get a steady value from a disconnected pin. You should expect random results unless you provide a pull-up (internal or external) or pull-down resistor. With a wire acting as an antenna you can expect even more randomness.