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

[Jiakang Lu]

Philip Levis wrote:
> 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
FYI.

I just checked the datasheet:
P = RSSI_value + RSSI_Offset, where RSSI_Offset = -45dBm.

Thank you again.

Jiakang