[Tinyos-help] Get RSSI value from the packet in T2?

[Philip Levis]

On Mar 1, 2007, at 11:12 AM, Jiakang Lu wrote:

> Philip Levis wrote:
>> On Mar 1, 2007, at 10:41 AM, Jiakang Lu wrote:
>>
>>> Hi all,
>>>
>>> Suppose we receive a packet from radio. How can we get the value  
>>> of RSSI in that packet? Other than pointing directly to the  
>>> metadata location, do we have any interface to get this value?
>>
>> If it's a CC2420 platform, CC2420Packet is the interface you want.
>>
>> Phil
> Thank you.
>
> One more question: how's the RSSI value represent in T2? The same  
> as TinyOS-1.x, rssi = (rssi >= 0)   rssi : rssi + 256?

I believe that the CC2420 RSSI value is the raw value from the radio.  
Please refer to the data sheet for details. It's a 2's complement  
signed number with a constant offset of something like -42 or -45.

Phil