[Tinyos-help] Accessing CC2420 RAM (SABUF)

[Razvan Musaloiu-E.]

Hi!

On Fri, 10 Jul 2009, Inco Mull wrote:

> Hope someone could give me some input:
>
> My configuration file contains the following lines:
> :
> :
> components new CC2420SpiC();
> MyApp.Ram_SABUF -> CC2420SpiC.SABUF;
> :
> :
>
> The component includes the following lines:
> :
> :
> interface CC2420Ram as Ram_SABUF;
> call Ram_SABUF.write(0,Temp,16)
> :
> :
>
> The application compiles OK but nothing is being written in the SABUF memory
> location. Any ideas on what I'm doing wrong?  I  enabled the crystal
> oscillator by using  "call Strobe_SXOSCON.strobe();" but no luck.
>
> Am I approaching the RAM writing process in the right way?

A good example for what you try to do are the CC2420KeysC.nc and 
CC2420KeysP.nc from here:
   http://hinrg.cs.jhu.edu/git/?p=jgko/tinyos-2.x.git;a=tree;f=tos/chips/cc2420/security;h=2ab8b09d68190089f5b4bfdeddada6649e6a0e19;hb=HEAD

You don't actually need the SXOSCON in order to be able to talk to access 
the SABUF. You do need to gain permission to the SPI bus using the 
Resource interface and you also need to properly toggle the chip select 
pin.

A note about SABUF: CC2420 is only capable to encrypt. There is no way to 
decrypt the using the CC2420 the content of the SABUF. :-)

All the best!
Razvan ME