Wired AND Wireless Embedded Ethernet Project

Question

Hey guys, I would like to design a device that is capable of connecting to a PC via WiFi or a wired connection (ideally Ethernet as well). I would like for it to be possible for a wired connection to be used while a wireless connection to a remote device is also able to communicate with the device (using the WiFi). So for this to be possible i believe that I would need a WiFi module and a wired Ethernet adapter controller. I would prefer to use Microchip devices and I have been studying their line of Ethernet controllers but it seems like it would be quite a challenge to configure their firmware stack to work with a wired connection and a wireless connection at the same time.

I guess my other alternative would be to use WiFi and RS-232 so that way I only need the stack for the wireless connection. That would simplify things greatly but I lose my ability to have true remote control from outside the building on my wired connection.

I guess this project would be similar to a printer that can be connected to using either WiFi, or a wired connection, or possibly both at the same time.

Has anyone worked on a project like this or have any suggestions for me?

Answer 1

I think you can get a DD-WRT capable router for USD$50, or maybe even less than that. I think you'll be hard pressed to put WiFi and wired ethernet onto a pic for much less than that. IIRC most of those routers have I2C or SPI you can pull out, and then you can just do whatever you've got to in Linux on a 200+MHz processor.

Answer 2

I think an embedded microcontroller running a free OS (e.g. Linux) is a good way to go. This question has some good suggestions for boards with wireless capability; most of them also can handle Ethernet.

Answer 3

Is this a one-off project or a product that will be shipped to customers?

For one-offs, there are a bunch of ethernet-capable MCU's with vendor-supplied TCP/IP stacks - go with those. Off the top of my head, I know Microchip and Zilog had such parts; and there are plenty others.

For the wireless features -- you could buy a WiFi module - Google for M2M wifi modules. They are expensive, though, and if you're focusing on one-off's, you might be better off just buying an ethernet-to-wifi bridge adapter. Heck, the DD-WRT that Jay Kominek mentioned would probably do the job nicely.

If you want to directly connect the ethernet MAC from your MCU to the MAC in the bridge/router, you can bypass the magnetics (isolation transformers) and just capacitively couple the MAC's together.