I see the Arduino Mega has a 3.3v pin, reading the specs it says it's coming from the FTDI chip. Is that only under power when the USB is connected? Again, I'm just a computer scientist, so I'm just guessing here
As far as I understand it, it is just a 3.3v power pin, not a 3.3v data pin. For those wireless chips you need 3.3v digital data rather than the 5v digital data that the arduino gives out. So you then need a logic level converter...
I would like to have the boards populated in the factory, and I'm still talking about having the CC2500 on the shield itself, so i'm supposing you'd need a machine to do that?
$20 usd is fine, that's roughly 12 pounds uk or 13.5 euro. At that price point you could have a operational sensor node for 45+20 usd, or ~44 euro.
If you are interested in getting the cheapest sensor node you can then you could add the atmega1280 chip to the board and have it all in one...
That's always an option, but I would like to still be able to use all the shields available for the arduino platform. It's really nice to be able to walk around with a node and have a little screen with debugging information about the routing tables in the neighbourhood for instance.
I'll have a talk with a couple of my EE buddies and see what they think. I'd probably be interested in an initial run of 25 boards. If they solder all the components for me all I have to do is send them a BOM and eagle drawing? Or should I source the CC2500 chips myself and have it shipped to them? What other steps besides designing the pcb would I need to take to get the final product sitting on my desk?