Hi Abbas,
If you check the datasheet for CC2420 (which you can find here: http://www.ti.com/lit/ds/symlink/cc2420.pdf), on page 51 Table 9 'Output power settings and typical current consumption @ 2.45 GHz' it lists 8 programmable power output levels: "The RF output power of the device is programmable and is controlled by the TXCTRL.PA_LEVEL register. Table 9 shows the output power for different settings, including the complete programming of the TXCTRL control register." PA_LEVEL Output Power [dBm] 31 0 27 -1 23 -3 19 -5 15 -7 11 -10 7 -15 3 -25 So I think what is happening is that setPower(1) is maybe setting the TX power control register to 1, which is not a valid PA_LEVEL, so the behaviour is undefined. You are seeing a sudden jump when you go up to level 3 because this is the first valid PA_LEVEL. Try using values 3, 7, 11, 15, 19, 23, 27 and 31 and see what happens. James ________________________________ From: [email protected] <[email protected]> Sent: 09 May 2017 20:24:18 To: James Allen (PGR) Subject: Re: [Tinyos-help] Transmission Range Hi James, I did not set it in Make file. I have used a simple timer which periodically run the code below: ------------------------------------------ call CC2420Packet.setPower(&_packet, 1); if (call AMSend.send(dest_Addr, &_packet, sizeof(msg_t)) == SUCCESS) { channel = busy; } ------------------------------------------ All the best, Abbas > HI Abbas, > > > How are you setting your 'power level 1' , 'power level 2' etc.? Is this > using CFLAGS in your Makefile or are you calling setPower on the packet, > or something else? Please share your code. > > James > > > ________________________________ > From: [email protected] > <[email protected]> on behalf of > [email protected] <[email protected]> > Sent: 04 May 2017 03:49:30 > To: James Allen (Student) > Cc: [email protected] > Subject: Re: [Tinyos-help] Transmission Range > > Thanks James, > > I have repeated the measurements a couple of times with different motes > (at least three motes) in an open space wide parking lot empty of cars, > and in a football field as well. > > The antenna of my sensors is PCB and as you mentioned, just a tiny shift > increases or reduces the transmission range. Even for the worst case (the > lowest range), the transmission range of power level 3 (and higher > levels) > is still much higher than that of level 1 and 2. > > The idea is to show higher power levels generate more strong noise and > wider range of interference. > > Cheers, > Abbas > > > >> Hi Abbas, >> >> Have you tried repeating your experiment in different environments, >> e.g. >> outdoors? Transmission ranges in the real world are unpredictable >> because >> they are affected by a great many factors, including the layout of >> buildings and surfaces around you, which can have unpredictable >> effects. >> The big jump is probably a random effect of signal bouncing, >> refractions, >> fading etc when you had the motes in a particular place. >> >> I have also found that the orientation of the antenna has a big effect >> with motes, especially the on-board kind which is embedded into the pcb >> - >> just a tiny shift can significantly improve or reduce transmission. >> >> So I would repeat it in multiple different locations and orientations >> and >> take an average. I would expect that to show more consistency. >> >> Also have you double checked the power levels against the cc2420 >> datasheet. >> >> Good luck >> >> James >> >> ________________________________ >> From: [email protected]<mailto:[email protected]> >> Sent: �03/�05/�2017 21:44 >> To: >> [email protected]<mailto:[email protected]> >> Subject: [Tinyos-help] Transmission Range >> >> Hello everybody, >> >> I measured the transmission range of CC2420 radio chip for a couple of >> power levels. I have got these measurements: >> >> power level 1 ----> 120 cm >> power level 2 -----> 150 cm >> power level 3 -----> 3550 cm >> power level 4 -----> 4050 cm >> power level 5 -----> 4450 cm >> power level 6 -----> 5020 cm >> >> Does anyone know what is the reason for such a big jump in the >> transmission range of power level 2 to power level 3. Notice that there >> is >> no a big difference between the output power of level 2 and 3. I think >> is >> it around -30 dBm for level 2 and -25dBm for level 3. >> >> *** I defined the transmission range as the maximum distance between >> transmitter and receiver so that at least 90% of the packets are >> delivered. *** >> >> All the best, >> Abbas >> >> _______________________________________________ >> Tinyos-help mailing list >> [email protected] >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> _______________________________________________ >> Tinyos-help mailing list >> [email protected] >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listi > > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help Abbas
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