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Support for USB Wi-Fi adapters or Xbee Wi-Fi 802.11 wireless


#1

Not sure if this topic was brought up before but I was wondering if there are any better\cheaper alternatives to the RS9110-N-11-21-01 WiFi module that sells for $99 which seems way too much (http://www.ghielectronics.com/catalog/product/282).

Would it be possible to use USB wireless adapters (you can buy these for $15-$20) with the GHI devices that support USB hosting?

Or how about the new Xbee wi-fi 802.11n that seem to match or exceed the features of the RS9110-N-11-21-01 device?
http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/xbee-wi-fi#overview
Datasheet: http://www.digi.com/pdf/ds_xbeewifi.pdf


#2

The wifi module is only about $30 in volume. http://www.ghielectronics.com/catalog/product/301


#3
  1. USB Wireless - you would have to write the driver(s).

  2. Digi Xbee wireless - it is not the same as the Red Pines or USB Wireless. It allows you to send serial data only. You cannot, for example, open sockets to use it as a HTTP client. Also, paying extra for the N radio is a waste, as a FEZ (or any other microcontroller) can’t handle 65 Mbps data rate.

  3. A component similar to the Xbee, but more resonably priced, is the RN-XV WiFly http://www.sparkfun.com/products/10822. It does B/G and has a few extra features over the Xbee. Also, I find the command syntax for this more intuitive.

  4. Wireless bridge sold here is great if you already have ethernet available. Once configured, it is “plug and play” for any ethernet connection (not just microcontrollers).

I’ve experimented with all of these solutions, except (1). Because I had already invested in ethernet hardware for most of my boards, the bridge has turned out to be the easiest and most reasonable solution. In the Xbee form factor category, the RN-XV won out over Xbee 802.11, both for cost and ease of configuration.

The cost of the Red Pines module sold here is because this technology is a difficult nut to crack on NETMF devices. GHI has put a lot of effort into this component.

Hope this helps!


#4

Thanks for your insight.

I guess my question came after I saw the $60 difference between the module itself and the breakout board. I don’t really believe the simple breakout board justifies $60, maybe for prototyping purposes it makes some sense. Are these gadgeteer devices meant to be development prototypes?

It would still be great to be able to use a USB wi-fi dongle since GHI devices support USB host, but after some googling it does seem like USB adapters are not based on a standard USB Wi-Fi class specification.
So it seems the only solution would be for GHI to invest some time into picking a good cheap wi-fi USB dongle and build drivers for it and sell it along the other wi-fi module as a USB alternative. I’m sure many people would opt for that, I would.


#5

The TCP/IP stack part of your driver would eat up most on the memory leaving close to nothing for other things. It’s not worth the trouble you’d have to put in.


#6

I believe GHI already has a TCP/IP stack which they can use to interface to any module that provides 802.11 connectivity. They may need to confirm that. The missing part would be a USB driver for a USB wi-fi adapter. I think we’re talking about SPI versus USB interfacing to such a network device. But I guess I could be wrong.


#7

On the smaller systems, GHI does not provide a stack. The stack is on the Ethernet (W5100) or WiFi cards.


#8

That sounds right, I was thinking more of the EMX and Hydra modules.

Will GHI release the schematics at least for the Wi-fi breakout board?


#9

I don’t speak for GHI, but I believe the open hardware logo on the modules give a clue to your question.


#10

Yeah I saw that but it looks like only the Hydra module is Open Hardware (even though right now it’s only open-schematic but that’s almost enough), not all the other gadgets have the OH logo. We’ll have to wait and see.


#11

The schematic for the Spider is online, as well as all the FEZ boards. The design files for most are also available.


#12

That’s sweet but unless I’m missing something, OSHW means schematics, bill of materials, mechanical drawings, PCB layout gerbers and drill files, plus drivers and software. In other words, everything that would allow anyone to replicate or manufacture the device, compile firmware, make any modifications, from scratch without having to redesign it.

I found the http://gadgeteer.codeplex.com/ link and looks like some of the schematics and boards are there, but not all of them yet.


#13

On the top of this page is a link to the GHI shop. In the catalog, check the download tab for each of the boards. You will find all sorts of interesting stuff.


#14

Sure thing. We are still negotiating with Redpine Signals (The WiFi RS21-01 module manufacturer) to release design reference documentation that does not conflict with the NDA signed with them.


#15

We haven’t added downloads to the gadgeteer modules on our website. Most files are on codeplex already.