So continuing my odyssey of firmware and hardware I have begun to produce a Zigbee based platform for my company.
It’s amazing to see the SOC designs coming out today that literally marry the best of worlds together.
This device from Atmel, the ATMEGA246RFR2 is a hybridization of previous chips combining the RF and Crypto into a single package. That’s awesome! Of course the only issue I am having is documentation and support. Sure there are forums.
A couple of wiki pages from various people. But no meat an potatoes for anything more than running and compiling their example projects. Until their latest release (ASF 3.11) the TWI interface had some minor bugs and was non-functional. The biggest issue for this package is the lack of secured demonstration projects, it’s ironic since they actually have buried in the ASF a full SAL (Security Abstraction Layer), which utilizes the on board AES co-processor. You will need to download the full ASF from here in order to extract the the SAL and STB. I have not been able to find an example program for the ATMEGA256RFR2 that properly deploys the SAL or STB. The Light Weight Mesh project provided by Atmel implements an independent security layer separate from their ASF Studio 6 implementations. If you swing by zigbee.org you can download several of the Zigbee Specifications. I found them invaluable for deciphering the Atmel Zigbee stack. Reading through the main ZigBee specification you see that they have stepped back from MAC security due to code space requirements for implementation. Ironically, the Atmel ASF library is a MAC based security implementation, which may explain why they have not actually released a secured network example. Either way, I need it so as I go I will be implementing it.