# Powering Yun

Hello everyone,

I'm quite new to the arduino platform and my electronics/programming skills range from average to bad, so please forgive my ignorance.

I've started a project based on an arduino Yun and trying to figure out how to power it. The enclosure will be pretty small, so I'm leaning towards a 2s lipo. Since the Yun doesn't have a regulated input, I'm thinking of using this:

Is it a good choice? I've read that Yun maxes out at around 350mA and the only thing I'll be connecting is an IMU plus a couple of LEDs, so I'm looking at 400-450mA max. I was told that it's quite noisy and might need a filter( a capacitor I'm guessing?) and that I'm better off using a BEC. The thing is that BECs tend to be way too big-at least the ones I've found.

I prefer not to use a 7805 or equivalent.

Thanks

I see no reason why that won't work. Adding a couple of capacitors to reduce noise is easy.

The Yun power consumption is well within that board's abilities: Arduino Yun, power draw - Arduino Yún - Arduino Forum

Using a 7805 or equivalent with batteries is inefficient - they convert a lot your precious battery power to heat.

Yeah, that's what I was thinking re: 7805, hence the decision to go for the other one.

Any idea how to calculate the capacitors required?

Put a 0.1uF ceramic on the output of the step-down, as close to the board as you can and with the leads as short as possible.

Put another one on the input to the Yun, as close to the Yun as you can and with the leads as short as possible.

Should be enough.

Forgive the ignorance, do you mean 1 capacitor between the regulator's output poles and another one between the Yun's input poles?

Thanks again,

Petros

Another question: Is it possible that you meant 1 capacitor across the reg's input instead of output and another one across Yun's input? I googled it a bit and couldn't find any circuits that use them as you described, but plenty the other way.

This is called a decoupling capacitor, right? Time to learn some theory!

petros0:
Forgive the ignorance, do you mean 1 capacitor between the regulator's output poles and another one between the Yun's input poles?

Yes.

petros0:
This is called a decoupling capacitor, right?

Yes.