I hope I am not beating a dead horse here. Several years ago I did a hobby project with USBIzi chip with a WiFly shield (e.g. connection via UART) . It worked, but I wouldn’t call it quality grade.
Fast forward to today and I need to do a more serious project. I’d like to use USBizi chip for its low cost, but I need a normal WiFi TCP/IP connection with the stack. The product page states that wired networking is possible with Wiznet w5100 and it works via SPI. At the same time, I see that GHI sells a RS9110-N-11-22-04 WiFi module (http://www.ghielectronics.com/catalog/product/378) which also connects via SPI. Is this an option? Is there a driver for it that I could use on the USBizi?
What you save in uC cost is where you’ll quickly miss out in connectivity.
The firmware additions that GHI did for USBizi to support Wiz5100 were specific for USBizi. There’s not enough memory to run a TCP/IP stack on the USBizi itself, so a possible solution would be to have a Ethernet to Wifi bridge connected to the WIZ5100 connected to the USBizi.
If I was seriously contemplating a commercial project, I’d go only with first-class single-hop device interconnections and go to a G120 based device and the GHI wifi solution. In fact, just buy the Wifi model Cobra 2’s and you’re done. Much easier to support than any hybrid solution I suspect.
Microchip sells a two-chip WiFi solution with built-in TCP/IP stack. It’s sorta the WizNet of WiFi, I guess. You’d have to build your own driver for it, but it shouldn’t be terribly difficult, since all the heavy lifting is done by the hardware.