Hi paul
Its strange i did similar tests with MICAz motes and even with default
transmission power I can get 10 meters.

Akankshu

On Thu, Dec 10, 2009 at 11:28 AM, Zhao Stephen <[email protected]> wrote:

> 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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