Looking for a low-power, low-footprint WiFi solution

Question

I am working on turning my Pi into a "Car-puter," and will be using one of the Pi-specific XBMC images (Xbian, Raspbian, perhaps OpenELEC). I would like to use the XBMC Android Remote app to be able to avoid having to have a monitor, mouse, or keyboard.

My question is, what would the best way to establish a WiFi connection between the phone and the Pi?

Right now my thought is to get a USB wireless dongle that supports ad-hoc, and then finding a way to get my rooted phone to support ad-hoc as well. Is this a reasonable route to go, or is there something easier/better? If that is a good way to go, are there any models that are recommended for this sort of situation? (I'm not extremely knowledgeable with networking)

I will be using a powered USB hub for all the devices I'll be connecting, so I'm not too worried about power draw. Also, I'll be keeping all the devices behind the dash board, so a full-sized router is out of the question.

Answer 1

I've had some success networking between the Pi and a phone using a wifi dongle supporting adhoc. Essentially, you set up the Pi as an access point using hostapd and run a DHCP server on the Pi to give an IP address.

I've just posted the details on my blog at www.recantha.co.uk/blog. Didn't really want to paste it all in here because I'm not sure how to get the preformatting working yet.

Blog post here

Answer 2

BT is a pain in the ass for everything that is not sharing a photo with another phone or having a call on your headset. BT is not for general purpose networking.

WiFi is the right choice, but the mode you are looking for is infrastructure-AP so that your Pi will become a real access point. So be really really careful about what dongle you buy. There are many combinations of drivers/chips that don't support AP nor ad-hoc network creation (mostly Broadcom AFAIK). I strongly suggest to pick up an Atheros or RT73 chip for this kind of things (even if it's hard to find Atheros chips inside USB dongles).

For example this should work because of its RT73 chip (as stated here, here and here). If you want to buy another dongle with another chip, then you'll have to investigate yourself if the chip supports infrastructure-AP mode.