Taking a closer look at these two low-cost software solutions:

uTasker

One possibility would be for me to more or less duplicate what the modules do: use an ARM processor and an ethernet-specific OS. uTasker is free to experiment with, and only $500 to buy for a product, so if it works it is a great way to go.

It has a simulator, which is very cool: I can write code for my gateway on the PC and simulate the final system. I’ll bet I could pull data in from a Zigbee system using their demo SW and then feed it to the silulator, for a complete system test?

Looking at the cost of supported micros:

• Freescale MC9S12NE64, which is $10/1, $7.50/1k at DK.
• NXP ARM chip LPC2364 which is only $8/1, $5.50/100, $5/1k. No phy, no crossover.
• Luminary Micro ARM chips (which start as low as $1.50/100 for the low end parts, look into that for other things!). Their cheapest one with Ethernet is $9/1, $7/100, $6/1k. They have MAC and PHY, and also auto crossover.

Next, look at cost of dev tools. Freescale uses CodeWarrior, but it starts to cost a lot of money at these flash sizes. They support GCC, but what platforms does it run on?

What about DHCP? Yes, it is supported.

I played around with the simulator, and looked at the docs, and I have to say that at first this seems way too complicated for me!

uP

This small-micro-optimized Ethernet stack is worth a closer look too.