Hi Vivek, Yes it is possible, but you will have to write some code by yourself. If you really want to control everything, then you have to write your own appication layer on top of the RF230DriverLayerP.nc. An alternate good solution would be:
Modify RF230RadioC and remove from the layers the CollisionAvoidance layer completely. Just remove the components and correct the wirings. Also remove the LowPowerListening, TrafficMonitor, SoftwareAck and CarrierSense layers. This will improve the timing a lot. You cannot use ACKS in this case. Modify the RF230RadioP.nc so that requiresRssiCca always return FALSE. This might not be necessary, but can help. Even if you do this, there is some problem: the upper part of the radio stack is running in task context. It is impossible to initiate any action from task context at microsecond precision. You might want to add another layer just above the driver which busy waits in microsecond precision till you want to send out your message. That will fix all of your problems. Hope you can pull this off. Best, Miklos On Tue, Jun 22, 2010 at 12:35 PM, <[email protected]> wrote: > HI. > > Thank you very much for your reply. > I think I am still stuck up with my problem. Here is the whole issue: > I have to send messages from two motes to the basestation at a very > small time difference. I want to plot the basestation's received > messasges on a time scale that is in microseconds. I had thought > disabling CCA would have enabled the motes to send at any time i want > them to. Even while doing what you had advised, I have found out that > there is a random time in the range of tens of milliseconds that the > motes take after giving the send command, even if there is only one > sending mote. Our main aim is to check if we are able to send messages > at such time instants that they are received at the basestation at > approximatesly the same time instant (our time scale has to be > microseconds). > Is that possible? If yes, I would like to request you to help me in > achieving this. > > Thank you. > Vivek Sharma. > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of Miklos > Maroti > Sent: maandag 14 juni 2010 15:17 > To: Sharma, V. (Vivek); TinyOS > Subject: Re: [Tinyos-help] Questions about Implementing Jamming Signals > > Hi! > > Use the latest CVS version of tinyos-2.x. Write an application that > continuously transmit messages. Then add these lines to your makefile: > > CFLAGS += -DRF230_BACKOFF_MIN=100 > CFLAGS += -DRF230_BACKOFF_INIT=100 > CFLAGS += -DRF230_BACKOFF_CONG=100 > > Then copy RF230DriverLayerP.nc into your application directory, and > comment out these lines: > > if( call Config.requiresRssiCca(msg) > && (readRegister(RF230_PHY_RSSI) & > RF230_RSSI_MASK) > ((rssiClear > + rssiBusy) >> 3) ) > return EBUSY; > > from the RadioSend.send command. > > This should give a pretty good jamming singnal :) If it is too good, > then increase the BACKOFF values (those are in microseconds). > > Best, > Miklos > > On Thu, Jun 10, 2010 at 4:17 PM, <[email protected]> wrote: >> Hi miklos, >> >> I am new to this tinyos software and for an experiment, i wanted to >> know if it is possible to disable the csma (cca is the same i guess), >> in the iris motes (rf230 radio). I would appreciate if you could tell >> the procedure to do the same. >> >> Thanks, >> Vivek sharma >> > _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
