Hi
I have a problem of channel detection.
The radio chip used is CC2420. The code is based on on TinyOS-1.x.
I want to use CCA to search or detect other channels.
Following is part of my code that related to this:
uint16_t count = 0;
for(ccaCheck = 0; ccaCheck < 400; ccaCheck++)
if(!call CC2420RadioControl.getCcaStatus())
count++;
if(count > 100)
debug(DBG_ERR, "channel =%i is detected \n", call
CC2420Control.GetPreset());
The definition of getCcaStatus is :
command bool CC2420RadioControl.getCcaStatus(){
return TOSH_READ_RADIO_CCA_PIN();
}
However, in my test, it seems incorrect. i use two nodes: One is working on
channel 11 and sending out packets at data rate of 2 packets per second. The
other node, woking on channel 21, does not send any packets. It uses above
code to detect channel.
The ouput is: channel = 21 is detected
channel = 21 is detected
That is not correct. It should not output anything.
In my understanding, if CCA pin is low, then the channel has not
transmission activity Is my understanding correct? What is wrong with my
code? Thanks for any advice.
--
Renjie Huang
Sensorweb Research Laboratory
http://sensorweb.vancouver.wsu.edu/
Washington State University
_______________________________________________
Tinyos-help mailing list
Tinyos-help@millennium.berkeley.edu
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
