Hi all

Reading through all the threads regarding wifi, I can't help but wonder how big a leap it would be to get the RTL8188-based wifi dongles going on mbed.

We already have the following:

1. lwIP
2. mbed-rtos
3. USBHost

So it seems a little push in the right direction could mean we have dirt-cheap WiFi in a tiny footprint to our avail.

Sure the GainSpan, CC3000 and WiFly's are nice but they are:

1. Expensive: RTL8188 $4-$8 vs $25-$40 for the various modules.
2. Larger: PCB footprint is larger than USB required for the dongle. Plus the USB can be used for other purposes if the dongle is unplugged.

Is anybody else thinking along these lines? It's been done on an ARM11 before, in the form of the Raspberry Pi.

I am a C++ developer but have never worked on hardware drivers before. I would gladly offer my time towards an open-source collaborative effort with someone / a team who has experience with the RTL8188 and/or driver development.

Regards

I once looked at it, since as you say wifi dongles would be by far the best solution for a wireless internet connection to an mbed. One of the main problems however is that contrary to for example serial over USB, and mass storage devices, there is no standardized wifi protocol for USB, so unless for the RTL8188 it is somewhere documented, it will mean alot of USB sniffing to see what is going on. And the question is how large the driver would be, an LPC1768 doesn't have the memory of an Raspberry. And I guess for the Raspberry it was more a port of existing linux drivers for the dongles.

Hi Jaun,

As Erik notice, the main problem is to implement the driver communication with RTL8188.

This chip is SoftMAC, then almost everything needs to be done at driver side:

"The RTL8188CU and RTL8192CU devices are SoftMAC devices, leaving most of the work to the driver. They need a firmware too, but it is much more lightweight (16KB)[1]".

Then a better alternative is find out a not so expansive WiFi chip with HW MAC.

BR,

Alan

1 - http://www.undeadly.org/cgi?action=article&sid=20101216231634

Using the RTL8188SU FullMAC also is not an alternative because you need to store more than 100KB firmware on microcontroller side. I'm searching to know if there is a RTL8188 FullMAC with firmware already flashed internally.

In principle 100kB still fits on an LPC1768. The 11u24 could store it on localfilesystem. But would this be something that has been done once, or is it done everytime on powerup? If it only needs to be done you can just tell uses to plug it in a pc to do that once, but if it is everytime that obviously isn't an option.