I tried an interesting thing today, suggested to me by one of my professors: Copy the TOS_Msg->strength to the data section before TOSBase actually sends it over the UART.
I did this: pBuf->data[2]=pBuf->strength; pBuf->data[1]=0x99; And then from there, examine the raw packet. The values that are copied into the data section are nothing like the 16 bits being called strength under the old AM.h. Though, the values that I copy into the data section change as I move the motes away from each other. When I leave the motes at a constant distance apart, the values stay very close together (vary by 1). I checked the CC2420 Manual and it says that it reports the RSSI in a range of 0-255, called LQI, link quality indicator. Any guesses to whether the 8 bits being copied into the data section are really the signal strength? Funny thing is, it really only goes from about 0xFF down to about 0xD2. I would *assume* that any signals lower than this cannot actually be picked up and are therefore dropped anyway. -Sam Pierson On 1/19/06, Michael Schippling <[EMAIL PROTECTED]> wrote: > again I could be wrong about this....but my one excursion into reading > radio strength on the host side indicated that it is not actually being > sent from TOSBase. I'd like to be proved wrong on that though. > > As long as you are within the TOS system itself, then everyone is > using the same TOSMsg struct and you are not faced with field > conversions. > > You might want to look through the CC2420 code in platform/micaz > and see where the ADC is being pinged for the RSSI value, and what > part of the 10bits is being truncated into the 8bit field. > > MS -- Sam Pierson _______________________________________________ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
