Re: [6lowpan] Fundamental concerns about 6lowpan ND

["Colin O'Flynn" <coflynn at newae.com>]

Hello,

>It is not fine to say, oh just add code to the edge router.  In the
>applications that I'm building (home controls, environmental
>monitoring, ...) cost is important and extra code costs.

I think the extra code is marginal here. Your usb stick that plugs into your
computer will have lots of extra horsepower [see example at end of e-mail].

And if you were making a 802.15.4 to Ethernet bridge, anything with an
Ethernet MAC built in will have even more SRAM/FLASH available. I'm all for
small code size and less complexity, but to me it seems:

- Your edge router or 802.15.4 to XXX bridge will have spare horsepower as
an artifact of how microcontrollers are priced / what features are included
- Using 6lowpan-ND saves complexity on end nodes, at the possible expense of
a little extra code at edge routers

Since you'll have more end nodes than edge routers, that trade-off seems
worth it to me!

Regards,

  -Colin


USB Microcontroller Pricing Examples:

With an Atmel micro, you might go for something like an AT32UC3B164 - 64K
flash, 16K SRAM, $3.48 in qty 100. That is the cheapest USB micro by Atmel
that would work - anything else would not have enough SRAM to implement a
USB Ethernet interface anyway. It's cheaper than the 8-bit AVRs with USB
interfaces....

If Microchip was your fancy, something like the PIC24FJ32GB002 at $2.70 in
qty 100. It has 8K SRAM and 32K of FLASH.