[Tinyos-devel] more bugging about current consumption on Mica Z in tinyos-2.x

[Murray, Ben]

Hi
sorry to drag up an old thread but I'm getting some rather strange results
wrt micaz current draw vs input voltage for the null application compiled in
TinyOS-2.x (I have tried the srec posted by Phil and get the same results).
Using a bench PSU (100mA limit) and a Fluke 75 multimeter so should be
resonably accurate down to ~10uA steps. Accurate enough to spot some trends
anyway...

The current drawn by a mote running the null application seems to depend on
its input voltage and in more than just a I=V/R way. Results are given below
for 3 motes (M1 and M2 bought in 2004, M3 bought in 2007). Currents are
shown in uA and values of 5 are shown when the value was recorded as "less
than 10uA". Values ending in a 5 record when the multimeter noticeably
flipped between two readings. These are the stable idle currents, typically
reached after a couple of seconds, occasionally taking longer to settle.

VCC   M1   M2   M3
------------------
2.1  430  430  440
2.2  520    5    5
2.3   10    5    5
2.4   15    5   20
2.5   40    5   40
2.6  125   15   50
2.7  600   30   60
2.8  350   90   60
2.9  380  140   70
3.0  500  200  100

I have only been messing around with the motes and TinyOS for a short while
so am certainly not adept with programming them yet - is there an easy way
to tell the mode what power state to go into as all I seem to be able to
find is McuSleep.sleep() which will set it to what the mote thinks is the
correct sleep level. I'm having trouble locating in which component the
McuPowerOverride interface is used?

Cheers,
Ben

*******************************************************************************
Please consider the environment before printing this email.
*******************************************************************************
This email and any files transmitted with it are intended solely for the use of
the individual or entity to whom they are addressed and may not be divulged to
any third party without the express permission of the originator.  Any views
expressed in this message are those of the individual sender, except where the
sender specifically states them to be the views of Thales Research & Technology
(UK) Limited.
*******************************************************************************