Support needed on understanding power stuffs in uno

Using Arduino Project Guidance
1

Hi I am a newbie in robotic projects..
From the internet, i quickly made some connections between my uno board and L298N motor driver with two dc motors and got it up and running..
but what confusing me is that of the power supply stuffs..

here is what my connection was:
L298N's +12V connected to Battery
L298N's +5v connected to +5v pin of Uno
L298N's GND connected to ground

Uno's Vin connected to another 9V battery (with a switch in between)
Uno's GND connected to ground

Rest other interfaces to DC motors, I know I have made it properly.

Now my question is:

  1. Even when my switch is in OFF position (connected to Vin of Uno), my board gets powered as soon as I connect battery +ve lead to +12v of L298N Motor driver
  2. The above question simply means that, the battery connected to Uno is of no value as it gets powered. Am I right?
  3. +5v mentioned in Uno is output voltage as per the spec. Then where is the input voltage by which Uno is getting powered. (If I remove the connection +5V of Uno to +5V of L298N, then board is not getting powered. So does this mean, +5V of Uno is input pin voltage?)

I m sorry if my question is vague..

2

You need to provide a drawing of the wiring arrangement. A verbal description is always doubtful. A photo of a pencil sketch will be fine.

...R

3

Is your L298N on a breakout board that might have a 5V regulator on it?

The +5V pin on the Arduino can be used as an output (getting power from USB or from VIN or the power jack through the Arduino's regulator) or it could be use as an input (providing regulated 5V to the Arduino's 5V power rail).

4

johnwasser:
Is your L298N on a breakout board that might have a 5V regulator on it?

The +5V pin on the Arduino can be used as an output (getting power from USB or from VIN or the power jack through the Arduino's regulator) or it could be use as an input (providing regulated 5V to the Arduino's 5V power rail).

Hi John, you said exactly what I wanted to hear. I never knew that +5V pin on arduino can be used as both input and output pin. Thanks!

5

Robin2:
You need to provide a drawing of the wiring arrangement. A verbal description is always doubtful. A photo of a pencil sketch will be fine.

...R

I am sorry, is there any software that can be used for this purpose?
As I was in hurry to leave my campus, I could not take effort in finding the software. Sorry for that.

6

is there any software that can be used for this purpose?

You could use the hardware mentioned, and then either photograph or scan the drawing.

7

newuserha:
I am sorry, is there any software that can be used for this purpose?

As I said in the piece you quoted, a photo of a pencil drawing will be fine.

...R