I’m looking at developing a system and wanted to add WiFi into the mix. I know Sparkfun really doesn’t offer anything in terms of WiFi chips but I figure there must be some people on here with some experience.
I really don’t know anything about WiFi (other than reading I have done on my own) and have a couple questions. If anyone could help out with suggestions or links to point me in the right direction…it’d be appreciated.
Still determining what micro I would like to use for my project…but the choice is based on this WiFi issue. I was thinking I could get a micro that has an ethernet controller built in…and then possibly drop a ethernet to wifi bridge in there…? Does such a thing exist? I have google’ed around and the best I could find was a lot of information on wireless routers…haha… I was hoping there might be a chip such as the SiLabs CP2102 that takes a UART signal and goes to USB.
Say I go with a micro without ethernet built into it. Such the case…then I’m not sure what I would be looking for. I have seen chips that are de/modulators and I have also seen chips that say they are transceivers. What’s the difference? After digging around a bit…I found what looked to be an interesting chip…but can’t find it available from anyone nor can I find an actual datasheet…which probably means getting any info would mean to sign a non-disclosure agreement…
With that chip…it seems like it would do everything I would want. My question with that is…say I hook it up with the SPI interface… Does that mean I build the TCP/IP packet on the micro side, then shoot it over byte by byte to this transceiver? Seems a bit slow to me…I thought it would more so be handled by some DMA transfer.
So yeah…if someone could point me in a direction for like…WiFi design for n00bs…that’d be great.
Most WiFi chips implement a lot of the MAC layer protocol in the host CPU, e.g,. laptop, PC, PDA. If this chip does this too, you’ll need a source for a large amount of complex software. Maybe this chip implements ALL of the MAC. I doubt it.
Then too, is the IP layer, if you want to use that. It is possible to do MAC address I/O with 802.11; it wouldn’t be WiFi.
If you don’t need high speed, the 802.15.4 with or without ZigBee is far easier and almost trivial. And cheap. SFE sells the XBee modules for this.
Another option is to purchase a WiFi to serial bridge module. These cost $125 or so (!) but are plug and play. Limited to serial port speeds. Lantronix has a range of these, from some that are perhaps under $100 as OEM modules and up.
Hi stevech and thanks for your response. I would have responded sooner…but the Memorial Day weekend had me at some BBQ’s this past weekend.
You bring up very valid points when it comes to the MAC and TCP/IP protocols and all the software behind them. I’m not too worried though…I can handle some pretty in-depth programming and have some people that know a great deal about TCP/IP programming that can help me out.
I just don’t know about WiFi hardware and that’s why I was posting. I have designed and implemented Zigbee systems before…but for this application there would be a need for faster data transfers and the ability to access the internet.
Yeah…those bridges would be something right up my alley…but wow…way too expensive for what I’m trying to develop.
Thanks for the suggestions…if anyone else has something they’d like to add…please do!
I recommend that you not use a product where the MAC layer is partially host based and not supplied by the vendor, for the OS you intend to use. Most embedded microprocessor applications use no OS at all.
This is layer 2.5 (part of the MAC) not layer 3 which is IP.
if you MUST use Wifi. consider a Lantronix Xport Direct. Low cost bridge from WiFi to high speed serial into the AVR. Check out Mouser Electronics’ prices.
I agree - use a module with serial interface. Digi has several that will work as well. Mouser carries them as well. Anecdotally, digi is better than lantronix but i have no firsthand knowledge.
