I'm trying to write code which will allow RSSI to be read as fast as possible, as far as I understand it there are roughly three ways to store RSSI, one would be directly to the CC2420 ram, the other being to the Motes 512kb of ram, and the next would be to stream the data through the usb interface of the MIB520.
My choice is to record RSSI through the serial interface of the MIB520, mainly because it will allow unlimited storage and I can measure for long periods of time. Right now I read RSSI through pMsg->strengh which gives the RSSI for incoming packets. I am more interested however in continually measuring RSSI both during a clear channel and during packet reception. From my knowledge HPLCC2420.read (CC2420_RSSI) is the most direct route to getting RSSI from the CC2420 and that RSSI is always available regardless of wether a packet is being received or not. I am unclear however how to call this function as fast as possible, ideally I would like RSSI to be sampled at 1kHz and continually streamed through the USB serial interface. Since the data rate for the serial transfer is 57.6kbps I'm assuming the most RSSI's you can get is somewhere on the order of 3000RSSI's/s so it seems feasible. On another note I'm having difficultly calling HPLCC2420.read (CC2420_RSSI) directly from my code, calling pMsg->strength is no problem however since I need RSSI during the time no packets are being received I assume I need to call HPLCC2420.read (CC2420_RSSI). Let me know if you have any questions (I'm sure you do!) Thanks, Nick
_______________________________________________ Tinyos-help mailing list [email protected] https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
