Hi, Thanks for your data.
I'm just wondering if there is any one else having similar result with yours before I accept it as my ground truth. 4-5 dB's difference is too large for my purpose. Or has anyone got a measurement conforming to the datasheet? On Tue, Feb 21, 2012 at 12:20 PM, Sergio Valcarcel <[email protected]>wrote: > Hi > > We sold a sma connector to the iMote2 board which was connected directly > to the spectrum analyzer, through a good and short cable (I assume < 1dB > att @ 2.4GHz). > > I did not use a vector network analyzer to check the impedance... so the > only thing I guess now is that we had to move one smd capacitor, which is > pretty small, so perhaps it was a bit burned after sold again. Hence the > output impedance could be a bit non-matched. > > I would not be surprised if the iMote is not giving 0 dBm, but some dB > less... > > > > On Tue, Feb 21, 2012 at 4:45 PM, Xiaohui Liu <[email protected]> wrote: > >> Hi, >> >> This is what the datasheet says: >> power vs dBm >> 3 -25 >> 7 -15 >> 11 -10 >> 15 -7 >> 19 -5 >> 24 -3 >> 27 -1 >> 31 0 >> >> Somehow your measurement of those power levels is 4-5 dBm lower than what >> is shown above. >> >> Are you using an attenuator over the antenna or measuring the power some >> distance away? I'm not familiar with spectrum analyzer, so I'm just giving >> some naive guess here. >> >> >> On Tue, Feb 21, 2012 at 7:52 AM, Sergio Valcarcel >> <[email protected]>wrote: >> >>> Hi, >>> >>> this is what I measured one and a half year ago using an iMote2 and a >>> spectrum analyzer, I actually demodulated the signal so you can be sure >>> that the values are quite accurate. >>> However the weird thing is that the mote did not rise to 0dBm, but only >>> to -4dBm. Sorry, I did not remember whether each column belongs to a >>> different mote. Also, note that setting the value to 0 it gives the maximum >>> power, but 1 stands for the least output power. >>> >>> 0 -4.1 >>> 1 -51 >>> 2 -46 >>> 3 -29 -28.9 4 -22 -22.8 5 -22 -22.7 6 -22 -22.5 7 -19 -19.4 8 >>> -16.5 -16.6 9 -16.5 -16.5 10 -16.5 -16.42 11 -15.5 -14.6 12 -13.8 >>> -12.7 13 -13.7 -12.7 14 -13.7 -12.6 15 -12.4 -11.4 16 -11.1 -10 17 >>> -10 -10 18 -10 -10 19 -9 -9 20 -8 -8 21 -8 -8 22 -8 -8 23 -7.2 >>> -7.2 24 -6.5 -6.3 25 -6.5 -6.3 26 -6.3 -6.3 27 -5.7 -5.6 28 -5 -4.9 >>> 29 -5 -4.9 30 -5 -4.9 31 -4.4 -4.3 >>> I hope this helps! >>> Cheers! >>> Sergio >>> >>> On Tue, Feb 21, 2012 at 6:10 AM, Xiaohui Liu <[email protected]> wrote: >>> >>>> Hi everyone, >>>> >>>> Does anyone know what the output powers are at each power level from 0 >>>> to 31 for CC2420? >>>> The CC2420 datasheet only gives the output power for level 3, 7, 11, >>>> 15, 19, 23, 27 and 31. However, the output power for other levels like 2 or >>>> 12 are missing. I find some threads such as >>>> 1<http://comments.gmane.org/gmane.os.tinyos.users/18536.>, >>>> 2<http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2009-March/039014.html> >>>> and >>>> 3<http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2007-August/027345.html>, >>>> asking similar question, but no definitive answers based on measurements >>>> have been given. Please advise. Your help is truly appreciated. >>>> >>>> -- >>>> -Xiaohui Liu >>>> >>>> _______________________________________________ >>>> Tinyos-help mailing list >>>> [email protected] >>>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>>> >>> >>> >> >> >> -- >> -Xiaohui Liu >> > > -- -Xiaohui Liu
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