Noob this help

Hi guys.
This is my first post.
I need a little help with this project.
I`m a totally noob about electronic and my english is not the best.
The circuit was working until I connected the 12v to the VIN on the Nano and the nano burned up.
So my question is how can I use only one power supply (the one on the diagram) which is 12v 4.5A 80W to feed the whole circuit without the need to use another power supply just to feed the nano.
And last ,how can I improve the circuit.

Thanks in advanced.

this is the circuit in question…

The circuit was working until I connected the 12v to the VIN on the Nano and the nano burned up.

Your Nano was probably incorrectly wired up, since 12V isn’t expected to cause your Nano to burn.

If your motor draws lots of power from the voltage supply at particular moments in time, it can lead to drops in voltage supplied to the Nano, which could maybe cause some glitchy behaviour. So people often use a separate supply for the microprocessor, or use some big capacitors across Vin to make up for it.

Otherwise, make sure that every Nano output is delivering current (and/or power) that is within specification values, since if we don’t realise that the Nano is outputting more current from an output pin that it can normally handle, then it can burn.

I though it burned because 12v was too much for the nano, before that I was using the output 5v from the easydriver to feed the nano with no issues, only problem was some leds were flickering when I adjust the rotary and the easydriver was getting very hot.
By the way how big do you suggest to be the capacitor ?

thanks for your comments

I think you are exceeding the max. current of 500ma for the NANO regulator UA78M05.The Easydriver built in regulator can output 1 amp but it need a heat sink. Since you do not have a heat sink it will get too hot and it will shutdown due to the high temperature. My suggestion it is to use an external LM7805 to supply the +5 volt the for the project.

Hi Franco,

Your diagram looks kinda like a hair knot to me. Can you draw each circuit independently? 4 circuits: the stepper motor and it's driver; the rotary encoder; the led matrix; and the wifi device. What does your code look like? It should be modular too.

For example, start with the stepper motor and it's driver and power supply - do a test sketch to make sure it works. Then add in the rotary encoder, then the led matrix, and finally the wifi connectivity. The order doesn't matter. but build it one sub-circuit at a time.

Whenever new circuitry or code don't work, comb the new addition for errors or conflicts. This approach turns a huge "It doesn't work" problem into a series of smaller, simpler steps.

Good luck - it also looks like the guts of a cool project!