Can you please describe the application?
Thanks,
Tal
> Hi,
>
>
>
> You could try something like the following in CC2420ReceiveP:
>
>
>
> uint16_t RSSI_Values[SomeNumberDeterminedByLengthofPkt];
>
>
>
> async command void CC2420Receive.sfd( uint16_t time ) {
>
> if ( call SpiResource.immediateRequest() == SUCCESS )
>
> sample_RSSI();
>
> ...
>
> }
>
>
>
> void sample_RSSI(){
>
> call CSN.clr();
>
> for (count=0; count < SomeNumberDeterminedByLengthofPkt; count++)
>
> call RSSI.read(RSSI_Values + count);
>
> call CSN.set();
>
> call SpiResource.release();
>
> }
>
>
>
> However this may cause other issues I'm not aware of. The way I
> understand
> this is that the MCU will sample the RSSI register over the bus while the
> CC2420 pulls in the data. When the data is fully in the RXFIFO it can be
> read out and you have both the packet and multiple RSSI samples. Of
> course
> you'd probably only get a small number of RSSI sample over a 40 byte
> packet.
> I'd be interested to hear your opinion on this Phil.
>
>
>
> Regards,
>
> Damien.
>
>
>
>
>
>
> On Jan 24, 2008, at 2:58 PM, Octav Chipara wrote:
>
> Hi,
>
> I'm trying to write an application that samples the RSSI register at
> high rates and also receives packets. However, it looks like most of
> the time the you cannot access the RSSI register due to having a
> single resource manager for the entire radio. From the cc2420 manual,
> my understanding is that you could both read the RSSI register and
> receive a packet at the same time. Is this correct? If so, was anyone
> able to do this. I guess you would have to multiple resource managers
> for the radio?!
>
>
>
> Software reads packets and the value of the RSSI register using a bus
> connected to the radio. So you can't read both a packet and the RSSI
> register at the same time. Therefore, you can't read the RSSI register at
> a
> rate faster than that determined by the time it takes to read a packet
> out.
>
>
>
> You can always just read the RSSI register continuously and let the radio
> hardware drop packets... Note that if it's issuing hardware
> acknowledgements, then you can't read the RSSI register while it is in TX
> mode (the valid bit in the reading will be low).
>
>
> Phil
>
>
>
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