One power supply for two things?

Hi everyone,

I currently am doing a project using an Arduino Uno (as seen here: http://forum.arduino.cc/index.php?PHPSESSID=mud8nnqch0nc0koa96nan151h6&topic=166837.0) and am using the same schematics as the project at the end of this page http://itp.nyu.edu/physcomp/Tutorials/HighCurrentLoads.

At the moment, I have a 12V power supply running to the breadboard that is powering the LED strip, but I also need USB to power the Arduino.

What would I do/how would I wire it up in order to get the Arduino and the LED strip running on the same power pack?
I was told I would need one of these http://www.jaycar.com.au/productView.asp?ID=MP3204 and that the power source would need to be in parallel?
I’m not sure how to do that though.

Any help is appreciated :slight_smile:

Thanks!

Well if you have +12vdc available on your breadboard and wish to power your Uno board from that voltage source then simply wire the +12vdc and a ground to your Uno’s Vin pin and ground pin. The Uno has a on-board +5vdc voltage regulator that will convert the 12vdc Vin voltage to +5vdc for the Arduino’s components.

Lefty

retrolefty: Well if you have +12vdc available on your breadboard and wish to power your Uno board from that voltage source then simply wire the +12vdc and a ground to your Uno's Vin pin and ground pin. The Uno has a on-board +5vdc voltage regulator that will convert the 12vdc Vin voltage to +5vdc for the Arduino's components.

Lefty

Is it true that the regulator will warm up quickly without any regulator though?

And also, I already have something going to the Arduino's ground pin...so do I just connect a wire to the breadboard that connects it to the ground pin of the Arduino?

wslyr:

retrolefty: Well if you have +12vdc available on your breadboard and wish to power your Uno board from that voltage source then simply wire the +12vdc and a ground to your Uno's Vin pin and ground pin. The Uno has a on-board +5vdc voltage regulator that will convert the 12vdc Vin voltage to +5vdc for the Arduino's components.

Lefty

Is it true that the regulator will warm up quickly without any regulator though? That question makes little sense? If you mean will the on board regulator run hot if it's input voltage is 12vdc, that depends directly on how much current you attempt to draw out of the Arduino 5V pin and how much current you draw out of the arduino output pins. However the regulator does have automatic over temp and over current shutdown protections so I wouldn't worry about it unless you actually run into a problem needing too much +5vdc current where you would then think about using an external voltage regulator to supply your external circuitry with 5 volt current. I like these little switching regulators:

http://www.ebay.com/itm/251066005460?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 Lefty And also, I already have something going to the Arduino's ground pin...so do I just connect a wire to the breadboard that connects it to the ground pin of the Arduino? There needs to be a direct wire from the negative of the 12 volt voltage source to any ground pin on the arduino board.

Hi,

I was just wondering if there is any other way to do this without using the VIN pin? Just exploring all options.

Thanks!

Yes, you can do this without using the Vin pin. Just take the wires you would have put into Vin and Gnd and connect them to a male barrel jack, such as this one http://www.adafruit.com/products/369 and plug that into the female barrel jack on the UNO. The link I posted has screw terminals on it, but you can also get a jack that you open up and solder together, but this is quick and easy!

Thanks, that helps heaps!

Just wondering where exactly would I put the wires to solder to the new plug?

Would it be 22C and the any of the negative bus spots?