3.3V arduino

Hey guys, I just bought my arduino uno, and want to power a nfr24L01, but it seems that the 3.3V output is not working. Do you know what's wrong with it? is it burnt? If so, what resistor should I use to power the nrf24L01 from the 5V output?

thanks, Julio

Resistor is not a good idea. Current draw by nRF24L01+ module varies from

Emission mode current(peak): 115mA Receive Mode Current(peak): 45mA Power-down mode current: 4.2uA

http://imall.iteadstudio.com/im120606002.html

The Uno has a decent 3.3V regulator on it that's good for a couple hundred mA. Are you sure it's not being shorted out by something and shutting itself down?

The first time I had that problem (for a GPS module) I bought a few of these:

http://www.digikey.com/scripts/DkSearch/dksus.dll?lang=en&vendor=0&WT.z_cid=ref_findchips0311_dkc_buynow&mpart=LM2937ET-3.3%2FNOPB&cur=USD

Very easy to get going and they step 5V down to 3.3V perfectly. It needs two caps, the datasheet gives good values under "typical application" and more info if your application is not typical.

CrossRoads: The Uno has a decent 3.3V regulator on it that's good for a couple hundred mA.

50mA actually: http://arduino.cc/en/Main/ArduinoBoardUno

That's all? Datasheet says 150mA max. http://www.ti.com/lit/ds/symlink/lp2985-18.pdf

Maybe the regulator varies on different Unos if the spec for the Uno says 50mA ? Still most regulators should be up to the task - so what is the evidence that "it seems that the 3.3V output is not working"? Measured with a multimeter?

Uno Rev 3 schematic only shows 1 part number.

Older units, where 3.3V came from FT232RL, 50mA was the limit.

CrossRoads: Uno Rev 3 schematic only shows 1 part number.

Older units, where 3.3V came from FT232RL, 50mA was the limit.

Oh, that's no doubt it. I've been living under a misconception. One of many no doubt ;) So another Arduino web page that needs updating.