Hi
Greg,
Here's the
CC1000ControlM file that performs the correct calibration procedure, and doubles
the throughput for mica2's (this is not compatible with mica2dot's for some
reason, even though they use the same 14.7456 MHz crystal).
MODEM0.XOSC_FREQ needed to be changed from a 1 to a 0 to double the
throughput.
You'll see 76.8
kBaud as opposed to 38.4 kBaud, faster startup, and the ability to change
frequencies in software correctly (although frequency performance and
characteristics will vary from mote to mote).
The CC1000 needs to
be calibrated when 1) the radio starts up, or the frequency changes 2)
there are large swings in temperature (think outdoors!) or 3) there are
large swings in supply voltage. A daily calibration would
be great to implement for outdoor applications.
There are 2
frequencies going on inside the CC1000 that need to be calibrated - Freq. A and
B. When the distance between these two frequencies is greater than
around 1 MHz, then separate, single calibrations need to be performed on
each frequency. When the distance between the 2 frequencies is less than 1
MHz (as it is on our motes) then a dual calibration can be performed to
calibrate both frequencies at once. Originally, the CC1000ControlM file
was created to perform separate, single calibrations, which takes
longer. Also, the local osciallator (LO) was not turned back
on automatically without transmitting after the dual calibration
completed, preventing frequency hopping schemes from
working.
The attached updated
CC1000ControlM file performs a dual
calibration procedure to do both frequencies at once, and the radio is
ready to go on both Rx and Tx after it gets done calibrating. It should
consume a little less energy when starting up the
radio.
-David
.
CC1000ControlM.nc
Description: Binary data
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