I went to Wireless Japan 2008 last week to check it out. In general, I don't like trade shows much, since I think they're an inefficient use of time. However now that I have a blog, I feel obliged to seek out interesting things to post. Unfortunately, there wasn't a whole lot that interested me but  here are some things that kind of tickled my pickle:

• The Zigbee pavilion was much more crowded than the Wi-Max pavilion, which was like a ghost town. I seriously felt bad for the vendors there. Go figure...
• There was a huge crowd at the TI Zigbee booth and everyone was asking fairly knowledgeable Zigbee questions. I was also surprised to hear many people asking questions about the CC2591 which was just announced. I guess that means that people are actively following Zigbee news.
  
• Renesas will be coming out with their first MCU + radio chip next year. This will be their first 802.15.4 chip and will probably be using the ZMD IP which runs at 900 MHz. Don't take my word for it, tho.
• People seem to be excited about Japan opening up the 950 MHz spectrum soon. There's currently an 802.15.4 group working on a variant to support this. The variant is called 802.15.4d and was previously posted in this article.
• This was the first time I saw Greenpeak with a booth in Japan. Looks like they opened up a Japanese office here now that they came out with their first silicon.
• I thorougly questioned a representative from one of the major Zigbee test houses and he didn't know that Zigbee 2007 was different than Zigbee Pro. This implies that there aren't a lot of companies testing for Zigbee 2007 (or the compliance tests aren't finished yet). 

One of the new TI modules. I compared it ...One of the new TI modules. I compared it ...

This picture didn't turn out that great. It'...This picture didn't turn out that great. It'...

Not sure why I took this. Toden uQuest is ...Not sure why I took this. Toden uQuest is ...

This is the Zigbee Pavilion which seemed to have ...This is the Zigbee Pavilion which seemed to have ...

Jennic was demonstrating MP3 streaming over 802.15.4. I wanted to ...Jennic was demonstrating MP3 streaming over 802.15.4. I wanted to ...

Radiopulse also had a karaoke mic streaming audio over 802.15.4. ...Radiopulse also had a karaoke mic streaming audio over 802.15.4. ...

Renesas' poster also described their roadmap and they'll ...Renesas' poster also described their roadmap and they'll ...

The Greenpeak demo was cool. All the switches are ...The Greenpeak demo was cool. All the switches are ...

Greenpeak's first silicon. Before they were only a ...Greenpeak's first silicon. Before they were only a ...

One of the software vendors had some cool software ...One of the software vendors had some cool software ...

Nordic had a large booth and was pushing their ...Nordic had a large booth and was pushing their ...

The Nordic ANT products are pretty well designed and ...The Nordic ANT products are pretty well designed and ...

The Continua Health Alliance looks pretty interesting. They are ...The Continua Health Alliance looks pretty interesting. They are ...

The Zigbee Smart Energy Profile has been getting a lot of attention recently, however there seems to be a lack of information on what the spec actually is. The info that I'm seeing in the press mostly deals with products that are coming out such as smart thermostats or perhaps the marketing research firms discussing the potential market size. There's no doubt that the smart energy market is potentially a very large market for Zigbee, but what exactly is it?

I should probably start with a small blurb on why smart energy seems to have such a large uptake in the US. The move to smart grids probably gained a lot of momentum from the Smart Grid Facilitation Act of 2007. The bill has passed through the committees and its currently on the legislative calendar. Here's a summary:

Smart Grid Facilitation Act of 2007 - Declares it is the policy of the United States:(1) to support the modernization of the electricity transmission and distribution system to incorporate digital information and controls technology and to share real-time pricing information with electricity customers; and (2) that electricity purchasers are entitled to receive information about the varying value of electricity at different times and places, and that states shall not prohibit or erect unreasonable barriers to the provision of such information flows to end users.

The implication of having some form of communications within the meters is that new applications can also be enabled. On the utilities side, automatic meter reading has the potential to save huge amounts since you won't need people to come by your house monthly and check your meter for usage data. All of this information would be available instantaneously via metering networks that the utilities could theoretically set up.

On the consumer side, it would be possible to get instantaneous pricing information on the electricity that is being used and to scale electricity consumption accordingly. I think if most people knew that their 500W PC that they leave on all the time is costing them an additional $100/month, they would be somewhat persuaded to turn it off every so often.

Basically, the Congressional bill, the recent focus on energy efficiency, and the buzz over wireless communication and wireless sensor networks has come together and made smart energy somewhat of a trendy thing. And in the middle of that is the Zigbee Alliance who is surfing the smart energy wave by coming out with the Smart Energy Profile to standardize wireless communications over 802.15.4 networks.

But probably most of you already know all about that. So let's dig into the details of the Zigbee Smart Energy Profile…

[Akiba] I spent the weekend checking out the Freescale MC13224 datasheet and writing the review. There are a lot of features so this is going to be a long post. For my sake, I've divided it up into sections. So grab a cup of coffee and sit back 'cuz this is gonna take some time...[/Akiba]

Freescale recently announced its MC13224 Platform in Package chip. Aside from the attempt at creating a new semiconductor marketing buzzword, it's a highly integrated chip that is almost an entire 802.15.4/Zigbee module on one chip. This is Freescale's 3rd generation 802.15.4 radio and it is definitely head and shoulders above its previous 802.15.4 SoC, the MC1321x series. The chip comes in a 9.5 x 9.5 mm, 99-pin LGA package and supports a temperature range of -40 to 105 degrees Celsius, otherwise known as industrial temp.

MCU
Just as a reference, the MC1321x series was based on the HCS08 line of 8-bit micros and feature tiny amounts of RAM and flash. The largest of the series, MC13213, had 60 kB of flash and 4 kB of RAM. In terms of Zigbee, you could probably fit the stack inside it, but you wouldn't have much room for anything else. Also, with 4 kB of RAM, it'd be extremely difficult to use that chip as a router. Since a router (ideally) requires a frame buffer pool, routing table, neighbor table, discovery table, indirect transmission queue, address table, binding table, group table, and discovery cache (did I miss anything?), it'd be amazing if you could fit all of that in 4 kB of code and still have room for a decent application.

The resource issue has been addressed in the MC13224. It features an ARM7 TDMI 32-bit processor, one of the first of the SoCs to use an ARM7 in fact. If you don't know about ARM7's, you've probably been hiding underneath a rock for the past 10 years. It's an extremely energy efficient 32-bit microprocessor and there's a wealth of tools available for development on it. There is an open source JTAG tool called OpenOCD which interfaces to the GNU Debugger (GDB) and also includes schematics for building your own JTAG hardware probe. The ARM-GCC compiler is actively maintained and has been stable and well optimized for a long time for the ARM7s. Also, there are a lot of OSes that are ported to it such as uCLinux, uCOS-II (RTOS), eCOS (RTOS), and FreeRTOS (RTOS). And that's just some of the open source OSes!

Also for those that believe that 8-bit micros are easier to use than 32-bit ones, I'd beg to differ. If you've ever programmed an 8051 using Keil, you'd know that you have to use a lot of non-ANSI compiler specific extensions due to limitations of the microcontroller. On the other hand, you can program an ARM7 in (almost) 100% ANSI C and have it portable to an AVR, MIPS, x86, or any other chip that supports an ANSI compiler.

Okay…enough with the microcontroller architecture preaching…let's get back to business...