3.7V to 5V Step up

[Nigel Goodwin]

If yes, to make sure i understood please
If 5v external power comes to the 5v pin,
It is possible to have a USB cable, which its 5v line is cut off, and program the Arduino as usual?

Yes, but it's easier to remove the fuse.

Here's the mini schematic.
[/QUOTE]

Hi Nigel
Thanks a lot!

For the moment I am using the Arduino uno.

I would like to make sure please that it is possible to do the same for the Arduino Uno?
That is, to cut the 5v line of a USB cable, and while the Arduino uno is powered from an external 5v power,
Then connect the modified USB cable to program the Arduino uno and download data from it?

Thanks
[/QUOTE]

Of course the boards are essentially the same.

However, I would still suggest it would be easier to remove the fuse on the Uno.

 

[EngIntoHW]

Yes, but it's easier to remove the fuse.

Here's the mini schematic.

Hi Nigel
Thanks a lot!

For the moment I am using the Arduino uno.

I would like to make sure please that it is possible to do the same for the Arduino Uno?
That is, to cut the 5v line of a USB cable, and while the Arduino uno is powered from an external 5v power,
Then connect the modified USB cable to program the Arduino uno and download data from it?

Thanks
[/QUOTE]

Of course the boards are essentially the same.

However, I would still suggest it would be easier to remove the fuse on the Uno.
[/QUOTE]

Thanks!
I think to keep the fuse so that I could use a normal USB cable when the external 5v is not powering the Arduino uno

 

[Nigel Goodwin]

Hi Nigel
Thanks a lot!

For the moment I am using the Arduino uno.

I would like to make sure please that it is possible to do the same for the Arduino Uno?
That is, to cut the 5v line of a USB cable, and while the Arduino uno is powered from an external 5v power,
Then connect the modified USB cable to program the Arduino uno and download data from it?

Thanks

Of course the boards are essentially the same.

However, I would still suggest it would be easier to remove the fuse on the Uno.
[/QUOTE]

Thanks!
I think to keep the fuse so that I could use a normal USB cable when the external 5v is not powering the Arduino uno
[/QUOTE]

Add a little switch in series with it.

 

[Musicmanager]

Can I ask what it is you intend to use this Uno to do ?

As others have suggested, using the 5v pin to power will work, but unless the I/O activity is minimal it does tend to be unstable.

I've done quite a lot of Arduino in various guises, and I would suggest using 2 x Lipo rechargeable batteries (18650 perhaps) and a two cell balance charger board. With the battery +ve connected to VIN and the negative to Gnd, you can use either the batteries or USB or both to power, the program lines are intact and the T1 Mosfet will manage the rest. There is then no need to remove anything.
With the addition of a 5vdc V. Reg. the batteries would also give you a more substantial power source for any external components.

MM