Thanks for all you guys' help. The problem is solved as you suggested. Thanks so much. now my nodes can only talk in about half one meter range.
Cheers Bai On Wed, Dec 17, 2008 at 5:46 PM, Urs Hunkeler <[email protected]> wrote: > Hi, > > A typical Makefile in TinyOS 2.x that I use looks something like this: > > -------------------- > > COMPONENT = MyDemoAppC > CFLAGS += "-DCC2420_DEF_RFPOWER=1" > #CFLAGS += "-DCC2420_DEF_CHANNEL=18" > #CFLAGS += "-DTOSH_DATA_LENGTH=64" > > include $(MAKERULES) > > -------------------- > > There is no need for any modifications in the code (if I remember > correctly, the TX power level was set in multiple places). Defining the > power level in the CFLAGS (as in the example above) will have precedence > over the values that would otherwise be set in the TinyOS code. > > You can also set the TX power level on a per-packet basis with code similar > to this (right before sending the packet): > > > -------------------- > > call CC2420Packet.setPower(&packet, pwr); > > -------------------- > > &packet is a reference to the radio packet you want to transmit > (message_t), pwr is the power level you want the packet to be sent with > (e.g. 3) and CC2420Packet is an interface available from the component > CC2420PacketC. > > I don't know whether there is a difference in the output power between 1 > and 3, but a value of 1 definitely works to reduce the power in my setup > (with telosb with the internal antenna I get a max tx distance of about 3m). > > If this still does not work for you, do you have modified hardware (e.g. > external antenna)? Do you at least observe a difference in the TX range > (e.g. 20m instead of 50m)? > > Cheers, > Urs > > > > BAI LI wrote: > >> I just tested it. Same here. Not working. Thanks for your help anyway. >> Any >> other ideas? >> >> Cheers, >> Bai >> >> On Wed, Dec 17, 2008 at 12:59 PM, Hui Kang <[email protected]> wrote: >> >> Add this line to your makefile and remove those macro. >>> CFLAGS=-DCC2420_DEF_RFPOWER=3 >>> >>> >>> - Hui >>> >>> BAI LI wrote: >>> >>> I read the cc2420 datasheet and modified it but unluckily it still didn't >>>> work. I modified the following code repectivcely. >>>> #ifndef CC2420_DEF_RFPOWER >>>> #define CC2420_DEF_RFPOWER 0x1F // changed the 0x1F to 3 or >>>> 1, >>>> didn't work. >>>> #endif >>>> cheers, >>>> Bai >>>> >>>
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