Dear Alex, The max. output power of CC2420 is 0dBm.
Therefore the max. power which can be received at the receiver mote is 0dBm ( very difficult in practice). You are getting -3dBm, which I believe is right, considering the losses (eventhough, you have kept them very close). Thanks Jobish John On Wed, May 13, 2015 at 1:25 AM, Alex Cp <[email protected]> wrote: > Hello Alex. > > Thanks for your reply. > > From the omnidirectional gain antenna of 5 dBi in each case mote TelosB > (Rssi Base and Sending Mote ) > > Probably, the Line loss is very high? but it seems to be little credible, > because in each case it will be -6.5 dB (impossible no?) > > PTx - Ltx+ Gtx+Grx-Lrx= > 0dBm - 6.5dB + 5 dBi + 5dBi - 6.5dB = -3dBm ???? > > > Alex CP. > CUC > > On Tue, May 12, 2015 at 2:31 PM, Alexander <[email protected]> wrote: > >> Hello Alex, >> Where you got GainTx and GainRx from? >> >> Regards, Alex. >> >> 12 мая 2015 г., в 22:07, Alex Cp <[email protected]> написал(а): >> >> Dear Jobish John. >> >> You know the reason about why the measure of the Rssi in the Base is >> -3dBm, because after make a link budget calculus it should be: 10 dBm when >> the two antennas are touching? >> >> >> Ptx+GainTx+GainRx= >> 0dBm+5dBi+5dBi= >> 10dBm >> >> Nevertheless the currently value obtained is -3dBm (The maximum value >> obtained in terms of wireless power) >> >> Thanks in advance for your kind answer. >> >> >> Alex CP >> CUC. >> >> >> >> >> >> On Sat, May 9, 2015 at 2:00 PM, < >> [email protected]> wrote: >> >>> Send Tinyos-help mailing list submissions to >>> [email protected] >>> >>> To subscribe or unsubscribe via the World Wide Web, visit >>> >>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>> >>> or, via email, send a message with subject or body 'help' to >>> [email protected] >>> >>> You can reach the person managing the list at >>> [email protected] >>> >>> When replying, please edit your Subject line so it is more specific >>> than "Re: Contents of Tinyos-help digest..." >>> >>> >>> Today's Topics: >>> >>> 1. Re: Rssi convert to dBm in TelosB (Alex Cp) >>> >>> >>> ---------------------------------------------------------------------- >>> >>> Message: 1 >>> Date: Sat, 9 May 2015 12:45:00 -0500 >>> From: Alex Cp <[email protected]> >>> Subject: Re: [Tinyos-help] Rssi convert to dBm in TelosB >>> To: tinyos-help <[email protected]> >>> Cc: ketan patel <[email protected]> >>> Message-ID: >>> <CAJk1sZ= >>> [email protected]> >>> Content-Type: text/plain; charset="utf-8" >>> >>> >>> Dear Jobish Jhon and Alexander. >>> >>> Thanks a lot for all advices. Currently are worked fine, and the best is >>> the fact that I know the calculus is very trustworthy (accurate >>> information >>> Jobish Jhon). >>> >>> Finally the file RssiDemo.java is now: >>> >>> ... >>> int source = message.getSerialPacket().get_header_src(); >>> double rssi = msg.get_rssi()-45; >>> System.out.println("Rssi Message received from node " + source + >>> ": Rssi = " + rssi + " " + "dBm"); >>> } >>> ... >>> >>> And mantaining the two TelosB motes very, very close (touching its >>> antennas) I've obtained: >>> >>> Rssi Message received from node 1: Rssi = -4.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -4.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> Rssi Message received from node 1: Rssi = -3.0 dBm >>> >>> Thanks a lot again!! >>> >>> Alex CP >>> CUC >>> >>> >>> On Sat, May 9, 2015 at 2:14 AM, JOBISH JOHN <[email protected]> >>> wrote: >>> >>> > Hi Alex, >>> > >>> > The datasheet (Page No: 11) of CC2420 says ? The range for RSSI is >>> > approximately from ?100 dBm to 0 dBm ?. Page No: 49 of CC2420 datasheet >>> > talks about substracting the offset value, -45 to get the dBm >>> equivalent. >>> > Page No: 10 of datasheet talks about the Receiver Sensitivity (Typ: -95 >>> > dBm). >>> > >>> > Your previous readings shows approx. 0 dBm (when both the motes placed >>> > very close) >>> > >>> > Try to increase the distance between the motes. When they get >>> > disconnected, the Rssi Message received on your PC will be close to >>> -50 ( >>> > so that -50 -45 = -95dBm) ( I am getting this value). >>> > >>> > Thus I believe subtracting -45 is enough. >>> > >>> > Thanks >>> > >>> > Jobish John >>> > >>> > >>> > >>> > >>> > >>> > On Sat, May 9, 2015 at 10:37 AM, Alex Cp <[email protected]> wrote: >>> > >>> >> Hi all. >>> >> >>> >> Im trying to convert in dBm the values obtained from the app: >>> >> >>> >> <http://tinyos.stanford.edu/tinyos-wiki/index.php/Rssi_Demo> >>> >> >>> >> In my case appears the next values: >>> >> >>> >> Rssi Message received from node 1: Rssi = 40 >>> >> Rssi Message received from node 1: Rssi = 41 >>> >> Rssi Message received from node 1: Rssi = 40 >>> >> Rssi Message received from node 1: Rssi = 40 >>> >> Rssi Message received from node 1: Rssi = 41 >>> >> >>> >> Because is very close both motes TelosB (Sending Mote and Rssi Base ) >>> >> >>> >> In the TinyOS tutorial appears the next: "...that this app prints only >>> >> the raw RSSI values ..." >>> >> >>> >> On the other hand I have the Data sheet of the RF Transceiver CC2420: >>> >> >>> >> <http://web.stanford.edu/class/cs244e/papers/cc2420.pdf> >>> >> >>> >> But is not clear to me How I can do the conversion from raw RSSI to >>> dBm. >>> >> >>> >> >>> >> I read, someone in the TinyOS mail-list, who wrote that is only >>> necessary >>> >> substract -45: >>> >> >>> >> < >>> >> >>> https://www.millennium.berkeley.edu/pipermail/tinyos-help/2014-March/058162.html >>> >> > >>> >> >>> >> But I suppose is not a exact calculation. >>> >> >>> >> I'll be grateful if somebody can generously explain how is the correct >>> >> way to convert raw RSSI values from a TelosB to a dBm. >>> >> >>> >> Thanks in advance. >>> >> >>> >> Alex. >>> >> >>> >> >>> >> Date: Mon, 3 Mar 2014 12:13:27 +0530 >>> >> From: ashok <[email protected]> >>> >> Subject: [Tinyos-help] RSSI DEMO >>> >> To: [email protected] >>> >> Message-ID: >>> >> <CAKs3p-d4GxW_dJjVc9Hwmk-+X_ZKi+hnvzCr+C2TS2NkuKg4uA@mail. >>> >> gmail.com> >>> >> Content-Type: text/plain; charset="iso-8859-1" >>> >> >>> >> Dear All, >>> >> >>> >> I am getting RSSI value in tinyos like: >>> >> >>> >> Rssi Message received from node 1: Rssi = -14 >>> >> Rssi Message received from node 1: Rssi = -1 >>> >> Rssi Message received from node 1: Rssi = 2 >>> >> Rssi Message received from node 1: Rssi = -2 >>> >> Rssi Message received from node 1: Rssi = 2 >>> >> Rssi Message received from node 1: Rssi = 0 >>> >> Rssi Message received from node 1: Rssi = -2 >>> >> Rssi Message received from node 1: Rssi = 2 >>> >> Rssi Message received from node 1: Rssi = 2 >>> >> >>> >> and I want to conform that is this value is in Dbm? >>> >> >>> >> if not than how can i convert it? >>> >> >>> >> regards, >>> >> >>> >> -ashok >>> >> >>> >> _______________________________________________ >>> >> Tinyos-help mailing list >>> >> [email protected] >>> >> >>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>> >> >>> > >>> > >>> -------------- next part -------------- >>> An HTML attachment was scrubbed... >>> URL: >>> https://www.millennium.berkeley.edu/pipermail/tinyos-help/attachments/20150509/3814e7ec/attachment-0001.htm >>> >>> ------------------------------ >>> >>> _______________________________________________ >>> Tinyos-help mailing list >>> [email protected] >>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>> >>> End of Tinyos-help Digest, Vol 145, Issue 8 >>> ******************************************* >>> >> >> >> > > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >
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