Hex or decimal doesn't matter, it's the same in the end, but since the
CC1000 datasheet specifies the TX power in hex, I always refer to it in
hex, that way there is less likelihood of an error occurring during
conversion.
The RF Power only matters for transmissions, it will have no effect when
the radio is in RX mode.
-Paul
On 12/10/2009 10:28 AM, Zhao Stephen 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] <mailto:[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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