How to fix a misconnection pin on a PCB

Using Arduino Project Guidance
1

Hi i am on a project which records sounds and play it.
i design a pcb and order it. when i made connections, it is very unstable and sometimes it didnt give correct pwm voltage from pwm pins. while researching i realized that i need to powered arduino above 6 volt from Vin pin. but unfortunatelly i powered with regulated 5v. firstly , this could be the possible problem?
secondly how can i fix it? make a direct connection between Vin and 5v pins could be the solution? but in this case both 5v and vin pins has 5v. is this harmful to regulator?

i am using arduino nano and nothing connedted to 5v pin right now. only a microphone to 3.3v pin.

Thank you?

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2

Connect the 5 volt power to the 5 volt pin. That is what it is there for, unless you are powering the Arduino from the USB connector.

3

howewer this is not my questions answer

4

No, but it will fix your problem.

5

then either i didnt understand you, or u didnt . i meant i have a pcb which connects 5v to Vin pin, not to 5v pin.in this case i connot change connections

6

Wire is made to fix such problems. Done all the time.

7

And a scalpel is used to cut PCB tracks when needed. Again a lot of that is done even in the professional environment, in fact possible a lot more.

8

do i really scalpel Vin pin? or just make a wire connection between Vin and 5v?

9

If you never are going to put more than 5volt (<5.5volt) on the V-in pin,
then you can safely connect the V-in pin to the 5volt pin.
Leo..

1 Like
10

@Wawa beat me to it (by hours!).

Stated differently if you short Vin and V5v together the regulator will not be damaged nor cause any unexpected current draw.

So you shouldn't have to cut, only jump the two ckts.

11

But please remember the lesson - the Nano (good pick for most tasks, more practical than the UNO) operates on 5 V which you supply via the 5 V pin.

"Vin" and the regulator is essentially an ornament from past days and is best avoided for any "real world" project. :roll_eyes:

1 Like
12

misleading IMHO

13

+1
Using V-in is perfectly fine if... you know it's limitations.
The Arduino documentation is unfortunately not very helpful about thermal limits.
Leo..

1 Like
14

Precisely why beginners should be strongly advised against it. :grin:

1 Like
15

thank you.

16

it is obvious when you learn it. but 2 days before, it was also obvious that i can powered arduino vin pin with 5v :smiley:

17

V-in goes through the 5volt regulator, and it might only be 4volt or so when it arrives on the 5volt pin. The processor is guaranteed to fully work from ~3.85volt with a 16Mhz clock, so it's still fine for the processor. But sensors and loads connected to the Nano might not like a potentially unstable 4volt supply.
Leo..

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