Power system from Single 2200mAh liPo battery (stuck)

Hi Ashley,

I don't have more detail, but some quick pointers for the right direction, so that you can google appropriately:

Resistors are not suitable for this use-case.

Use DC-DC converters for obtaining a 3.3V supply, then you can power the Xbee, GPS device and compass since they all support 3.3V operation according to your list. 3.3V is a popular value and is advisable.

You probably need a 3W DC-DC converter - costs about $10-15 at a guess.

The Arduino will run fine from the 11.1V battery directly, even at 12.4V.

Bear in mind, if you've got Arduino Uno outputs then they are at 5V and you need to level-convert to 3.3V (the other direction is fine).

If you're not familiar with this, try to look for a ready-built level converter, probably Adafruit or someone will sell them.

Thanks, So something like this would be a good idea?

http://www.ebay.co.uk/itm/251066005460?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Only problem with this is delivery date, but i brought it anyway, £1.30

which is an adjustable Dc-Dc converter (switcher).

Ideally i need something i can pick up in a store straight away. (maplins for example)

Another factor which im aware of is fluctuations in mA, what would be the best way to protect parts from these fluctuations?

Farnell will send it next-day as standard (order above £20 for free shipping) - I had meant something of the type michaelkellett had mentioned.

if you can run your Arduino Uno from 5V direct, then go with that DC-DC converter (the Tracopower one mentioned), i.e. power the Arduino from one of the pins, not from the DC jack.

Otherwise, for the 3.3V one I mentioned, then something like this: http://uk.farnell.com/xp-power/jca0312s03/converter-dc-dc-1o-p-3w-3-3v/dp/1289185

Maplin won't have such a thing in-store, it is a bit too specialist for them.

All the advice in this thread is highly useful, so worth reading. As mcb1 mentions, you could also consider running the microcontroller from 3.3V too, saves level converter efforts too.

Farnell will send it next-day as standard (order above £20 for free shipping) - I had meant something of the type michaelkellett had mentioned.

if you can run your Arduino Uno from 5V direct, then go with that DC-DC converter (the Tracopower one mentioned), i.e. power the Arduino from one of the pins, not from the DC jack.

Otherwise, for the 3.3V one I mentioned, then something like this: http://uk.farnell.com/xp-power/jca0312s03/converter-dc-dc-1o-p-3w-3-3v/dp/1289185

Maplin won't have such a thing in-store, it is a bit too specialist for them.

All the advice in this thread is highly useful, so worth reading. As mcb1 mentions, you could also consider running the microcontroller from 3.3V too, saves level converter efforts too.