Dear Paul,
Many thanks for your help.
Do you mean to set hex digits in SetRFPower()? It is interesting, do you
think it can not recognize decimal digits?
I should use SetRFPower(0xFF) on both receiver and transmitter? Maybe it is
no use for receiver.
Best
Zhao
2009/12/9 Paul Johnson <[email protected]>
> Zhao,
>
> My first thought, from running my own experiments is that it has something
> to do with the transmission power. 9 m is about what I would see with the
> mica2 in 900 MHz(it uses the same hardware as 433 MHz, but a couple
> capacitor values are different) when i set the transmission power to 0x02
> (which by the data sheet should be -20 dBm).
>
> However, there can be many reasons why the transmission range is short.
> Are there any obstructions between the two motes? Are you using the 433 MHz
> antennas (they should be somewhere around 17 cm long, I don't remember
> off-hand, but the 900 MHz whip antennas are approximately 8 cm long)? Are
> the antennas oriented vertically on both motes? Are you aware of any other
> devices operating in the 433 MHz frequency range? If the the motes are
> battery powered, are they running low? How are you setting the frequency,
> are you manually tuning or using a preset? (If you are manually tuning, i
> recommend using one of the 433 presets for control purposes)
>
> A couple of things I would recommend you try:
> 1) Try using the default power level (0x80) <- hex, not decimal and see
> what range you achieve. When chaning the power level, make sure you only
> use values listed on the CC1000 data sheet, otherwise you might get
> unexpected results. i.e. Going from 0x0F to 0x10, you will actually see a
> decrease in transmission power.
> 2) Try a different pair of motes, it is possible that one or both of
> the motes you used have hardware problems. The antenna connector might not
> be fully soldered on, etc.
> 3) Try the experiment in another location
>
> Hope this helps,
> -Paul
>
>
>
>
> On 12/10/2009 6:08 AM, Zhao Stephen wrote:
>
> Dear all
>
> I just test the rf coverage of mica2 in outdoor. two mica2 nodes are used,
> one is transmitter and the other is receiver. But the maximum range is
> around 9 meters, beyond that the receiver has no response. It is normal? In
> my setting, mica2 use 434Mhz and CC1000ControlM.SetRFPower(255).
>
> Why?
>
> Thanks
>
>
>
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