[mc1322x] Contiki tree resync

[Jon Smirl]

On Fri, Oct 30, 2009 at 1:58 PM, Mariano Alvira <mar at devl.org> wrote:
> On Fri, Oct 30, 2009 at 01:41:50PM -0400, Jon Smirl wrote:
>>
>> The 802.15.4 serial driver is not an approach I have tried. It is
>> designed around having a serially connect radio with no embedded CPU.
>
> I see. The last time I tried that it worked quite well. I'm not sure
> how far along those guys are though.  But I agree, the mc13224v
> probably isn't what you want necessarily, since the embedded CPU is a
> little redundant in that case. As a development platform though it was
> very easy to get going.

The problem is that the lowest silicon cost solution in all three of
the cases where we need 802.15.4 is different.

Remote switches - Freescale mc1322x, $4.50
Embedded node - serial radio like Atmel AT86RF230, $2.50
USB Bridge using existing router/PC - TI cc2531, $5.50

EM351 says $3, but when I inquired that was at 10M quantity.

So in order to stay sane with the software the plan is mc1322x
everywhere. You can buy it right now at Mouser for $4.50 so the price
is real.

Remote switches - Freescale mc1322x, $4.50
Embedded node - mc1322x $4.50, $2.00 disadvantage
USB Bridge using existing router/PC - mc1322x + ft232, $2.50 disadvantage

We need the highest volume in the switches. Depending on what the
state of the Linux 802.15.4 serial support is, it may be simple to
switch to the AT86RF230 in the embedded node case.

I'm still hoping that someone in China builds a retail USB 802.15.4
stick that we can OEM for $10.  I haven't located one yet. All of
these Zigbee based smart meters may trigger someone into building one.
But we don't really have to have this stick since we can route using
the embedded nodes. I also suspect Cisco is making a home router with
802.15.4 integrated given their presence on the 6lowpan/ROLL
committees.

If we could build cost effective 802.11 switches we would. But I can't
figure out how to do that for less than a $10 delta over 802.15.4,
There's no microcontroller/802.11 combined chip that I can find where
we can add our own code and not use a host CPU. None of our stuff is
battery powered.


>
>>
>> The contiki support for the Atmel Raven USB stick makes it look like
>> an USB Ethernet adapter. The 802.15.4 MAC runs in the Raven stick so
>> Linux is not aware it is doing 802.15.4. You don't need any special
>> support in the kernel. This model works with the stock Ubuntu kernel
>> and WRT router software (you need to enable the USB Ethernet driver in
>> WRT).
>
> I understand.
>
>>
>> If you're going to build a USB stick for this purpose the TI CC2531 is
>> a better chip. USB, CPU and radio all in a single chip solution. I
>> have a TI CC253x development kit sitting here for that reason but I
>> haven't opened it yet.
>
> Sure, that makes sense. Although shy away from doing USB stack
> development. It took me about 2 hours to get the serial driver up and
> running and the linux examples going with the mc13224v. I imagine for
> the TI part you either need to use their USB code or write your own
> USB stack like Akiba (or port FreakUSB to that part).
>
> -Mar.
>



-- 
Jon Smirl
jonsmirl at gmail.com