Pi-Point – turn your Raspberry Pi into a wireless access point

I was shown Pi Point before the holidays, but thought it was best to wait until now to spring it on you, because so many of you have got Pis for Christmas and are looking for projects to use them in.

Guy Eastwood has documentation and an SD card image which will allow you to turn your Pi into a wireless access point. With a bit of imagination applied, you can find a million uses for a tiny, waterproofable (think Tupperware and epoxy), cheap access point; of course, you can just use it to extend your home network, but the possibilities get really interesting if you think outside the box. You can build a guest network, firewalled off from your local network. You can learn about network hardening. With the addition of a home-made cantenna, you could set up a line of Pis as relays to get WiFi down to the shed in your allotment, or point a signal at your treehouse. If you’re an altruist, you can provide your local bus stop with free WiFi. 

Let us know what you end up doing with Pi-Point. We’d love to hear what you come up with!

23 comments

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Could it be used as a system of relaying internet through to remote villages?

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Absolutely no reason why not. That was actually an application we were talking about before we’d even released the Model B last February!

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Link appears to be wrong. It’s returning a page not found error.

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The link’s fine; I think what you’re experiencing is the Pi effect. Sometimes when we blog or tweet something the traffic spike knocks over whatever we’re linking to temporarily.

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Excellent. There’s an early attempt at a similar goal at https://github.com/ghoulmann/RasWAP.

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Excellent idea!

The Pi’s 100mb/s ethernet port will limit network traffic from 802.11n connections which is bit of a shame, but it certainly has a lot of potential for garden and obscure situations.

Are there any plans for the Pi to get gigabit ethernet in the future?

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Not at the moment – doesn’t fit into the cost model, I’m afraid.

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I’d guess that the vast majority of situations in which a Pi-Point would be used, are those with less than 100 Mbps upstream link capability. (Or maybe I’m just living in an internet backwater, with my DSL peaking at 15 Mbps on a good day)

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Sadly, many N WiFi routers you can buy these days only have 100 Mbps ports too… So for all the posturing of 300 Mbps of N, doesn’t do much good :-(

And yes, I have two of that sort – A Buffalo WLI-TX4-AG300N Ethernet Bridge and a TRENDnet TEW-671BR Wireless Router.

Anyway, point is that REALLY, when push comes to shove, having 100 Mbps for the network cable isn’t that big of a deal since really, you’re not getting 300 Mbps from the wireless in the “real world” anyway…

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Hi,

Guy is also working on a detailed writeup for the MagPi. Look out for his articles in future MagPi issues.

Regards,

Will

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For networking applications try also IPFire 2.13test ( http://www.ipfire.org ) on the RaspberryPi. It also support using additional USB Wifi stick as wireless AP (install hostapd addon via pakfire) and many more networking features like url-filtering, IPSec and OpenVPN VPN’s, 3G Dialup and more.
http://wiki.ipfire.org/en/hardware/arm/rpi#raspberry_pi

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Perfect! My gran needs a wifi router as her room only has Ethernet. This seems to be the cheapest and most effective option.

Looks like I will be buying a third raspberry pi (possibly a model A with a usb wifi adapter) for this purpose.

Thanks chaps and chapettes.

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Model A doesn’t have Ethernet, so it won’t work for your application, will it?

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Ah, yes good point. I guess I’ll use a model B then. Shame, I really want a reason to buy a model A….

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OK got it, gonna try it tomorrow to see how it goes! thanks

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Talk about timing. Today I wanted to figure out how to login on a Pi over wifi. Next week I’m going on a snowboard trip for the first time an I tend to shoot a lot of footage with my Canon 7D. Not having the luxury of infinite highspeed flashcards I’ll need some way of dumping my media on some other storage. The big thing is I don’t want to take my Macbook Pro with me. I’ve got too much luggage on me as it is in my view. So the idea was to somehow build an image for my Pi to which I can attach my flashcard reader and a small HD and then login to it over wifi en control the copy action from device to device. All without keyboards or tv’s, just my trusty HTC Vision. I think I’m going for a web2py setup on archlinux as I’ve got experience with both. If anyone has some tips or feature suggestions (like in phone browser media previews) let me know. When I’m sort of done with it I’ll set up a github repo for everyone.

Rio

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Hi!
If you interested in networking, i recommend you http://openwrt.org and if you used routerboard/mikrotik before, it will be much simpler!

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It can be a little tricky to figure out which wifi dongles permit AP mode; there’s some documentation here:
http://linuxwireless.org/en/users/Drivers
But it’s not complete, and wifi device manufacturers aren’t always forthcoming about the chipsets they’re using… RT3070 based devices look like a good bet ATM, I *think*.

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Interesting.

Would probably be good if the developer used a more minimal filesystem. 500MB seems quite lofty, and a Buildroot environment (if the sole purpose is to act as a router), would be a good route to go. This could run in memory as initramfs, with a separate storage partition. This would allow factory-restore, which would be more routeresque.

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I followed the steps at pi-point, but found that my EdiMax wouldn’t work with the hostapd on the RPi. I finally found this blog http://blog.sip2serve.com/post/38010690418/raspberry-pi-access-point-using-rtl8192cu which includes a link to a replacement hostapd binary. After loading it and changing the driver= line as directed, my Pi with EdiMax is working great as an access point!

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I am using my raspi as an access point with AirPlay in my car. How do I stop my iPhone from thinking the ap has Internet? I.e. iPhone connected to ap but still access 3/4G?

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Bridge your 3G connection with your wifi connection, and make your 3G connection your gateway address for the ap.

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ok, a wifi relay is not the same as a wifi access point, and is much more complex to link 2 wifi networks together as a repeater. I am still working on roughing out the details. Co-conspirators are sought.

HOWEVER, as a radio amateur, I am experienced with 2 meter repeater considerations, and can make these helpful suggestions:

Considerations:
* jamming; at VERY close range, even wide channel separation is not enough to avoid overloading the front end of the each other unit’s receiver. A simple solution is SPACE diversity; place 2 DIRECTIONAL antennas ‘back to back’ with powerful antennas and very sensitive receivers as far apart as practical, with the transceiver in the case of the antenna or it’s mounting base. run a USB wire from each to the pi’s powered hub. This thing will draw a SIGNIFICANT amount of current, around 1/4 to 1/3 amp @ 5 volts PER ANTENNA ARRAY.

*Mount both on a small sheet metal shed or large box- a telephone pole for example. Ground that box of course. MAKE SURE there is a metal plate between them to further weaken signal to reduce jamming between transceivers. This CAN be the box or shed. Higher is better, but sheds on telephone poles cause talk. Metal boxes are more common and less noticed. That box is the metal shield between antennas. Up high, stick a lighting arrester brush terminal on top, and a heavy ground wire to ground.

*Place them on 2 channels as widely apart as possible; 1 and 11 or 1 and 13, depending on local law. This is FREQUENCY diversity

POWER:
*If solar powered, make sure the battery is large enough to carry the system for 3 days of cloudy weather.

*Whatever you calculate is the needed solar array capability, double it; you will be glad you did the first time you get a nasty week of weather.

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