[Tinyos-help] Again!!!! Low-power CC2420 multihop in TinyOS2.xquestion????

Sun Aug 5 18:48:50 PDT 2007

Hi David,

I used oscilloscope to check the power consumtion. I
am measuring voltage drop across a small resistor
connected in series to the Vcc input from battery.

Following are the results I get with CTP-LPL in micaz:

Current
^
|      <-T1 ->
|      |-----|       |-------|C1
|      |     |<-T2-> |       |
|  ----|     |-------|       |-----C2
--------------------------------------------> time

T1 = time period when current consumption is high
T2 = time period when current consumption is low
C1 = Current when mote is in wake up mode
C2 = Current when mote is sleeping

Case 1.
RxSleep = Localsleep = 1 sec
Periodic packet sending period = 1 sec
Power consumption: T1 ~= 132ms, T2 ~= 820ms, C1
~=28.4mA, C2 ~= 4.4 mA

Case 2.
RxSleep = Localsleep = 1 sec
Periodic packet sending period = 10 sec
Power consumption: T1 ~= 1s, T2 ~= 20s, C1 ~=28.4mA,
C2 ~= 4.4 mA
In case 2, the graph in oscilloscope was not very
consistent. The values of T1 and T2 were changing a
lot. Also there were approx 10 spikes in the region
where mote was sleeping. I guess it was due to the
periodic beaconing in CTP routing protocol. Also there
were few packet losses. The above stated values are
average values.

Case 3.
RxSleep = Localsleep = 10 sec
Periodic packet sending period = 10 sec
Power consumption: T1 = 3 to 10s, T2 = 50 to 80s, C1
~=30mA, C2 ~= 6.8 mA

In case 3 also, the graph in oscilloscope was not very
consistent. The values of T1 and T2 were changing a
lot. Also there were approx 20 to 40 spikes in the
region where mote was sleeping.  Also there were many
packet losses.

I tried with LplUnicast and LplBroadcast also. In that
case the sleep current was ~=400uA. This is also not
very low but is fairly good.

I am not able to find why there is so huge diffenrence
in power consumption between CTP and LPLUnicast.

Regards
Ravi

--- David Moss <dmm at rincon.com> wrote:

> Hi Ravi,
> 
> What is the rxInterval you're setting?  And what are
> you using the measure
> the current consumption?
> 
> -David
> 
> 
> 
> -----Original Message-----
> From: tinyos-help-bounces at Millennium.Berkeley.EDU
> [mailto:tinyos-help-bounces at Millennium.Berkeley.EDU]
> On Behalf Of Ravi
> Prasad
> Sent: Friday, August 03, 2007 2:30 AM
> To: lim at tik.ee.ethz.ch
> Cc: Philip Levis;
> tinyos-help at Millennium.Berkeley.EDU
> Subject: Re: [Tinyos-help] Again!!!! Low-power
> CC2420 multihop in
> TinyOS2.xquestion????
> 
> 
> 
> Hi Roman,
> 
> Thank you.
> 
> Have you tested your modified CTP using CC2420LPL??
> What was the power consumption??
> 
> I also used another approach ( a dirty quick fix,
> but
> it was fastest approach) for using LPL in CTP. I
> modified the DefaultLpl.nc file to use a specified
> sleep period for all packets it transmitts. As every
> packet passes through this layer, this sleep period
> is
> applied to all Tx packets.
> 
> This approach is performimg duty cycle but the power
> consumption is again very huge. The lowest
> consumption
> is 4mA. 
> 
> The power consumption is same as was in case when I
> set the Rx sleep perion in top level application
> only
> for the application level packet. This I stated in
> my
> previous email.
> 
> So untill now I am not able to get the 200-400uA
> sleep
> current in CTA.
> 
> What do you suggest to get lower power consumtion?
> 
> Or again same question--Do you think I should try
> another multihop routing protocol over CC2420 LPL??
> 
> 
> Regards
> Ravi
> 
> 
> --- Roman Lim <rlim at ee.ethz.ch> wrote:
> 
> > Hi
> > 
> > In order to use lpl with ctp you could modify the
> > ctpforwarding engine
> > and add the lpl information for transmission.
> > I added an interface where you can tell the ctp
> > layer to use a default
> > rx sleep interval for forwarded packets.
> > 
> > roman
> > 
> > Ravi Prasad wrote:
> > > Dear Philip,
> > > 
> > > Thank you for your reply.
> > > 
> > > As you said that CC2420 LPL in Tinyos2.x works
> > with
> > > arbitrary topologies, I tried to use LPL with
> > > collection protocol provided in tinyos2.0.2. I
> > used
> > > the LowPowerListening interface in my top level
> > > application  to set the sleep interval of TX and
> > Rx
> > > sides. The application somehow worked with one
> > > transmitter & one receiver. But the lowest
> current
> > > consumption was 4mA which is very huge. Also the
> > > initial tree formation time is very big. If I
> use
> > a
> > > sleep interval of more than 3seconds the tree
> > dosent
> > > even forms and nothing works.
> > > 
> > > I think as the CollectionTree also uses
> > ActiveMessage
> > > to send/receive data/routing packets, the
> > > sleepinterval setting should be controlled at a
> > single
> > > point from where all packets (i.e routing and
> > data)
> > > flow, that is the ActiveMessage component.
> > > 
> > > Can you please comment on the above?
> > > 
> > > Also it would be great if you have some
> suggestion
> > to
> > > use another multihop routing on top of
> CC2420LPL.
> > > 
> > > 
> > > Regards
> > > Ravi
> > > --- Philip Levis <pal at cs.stanford.edu> wrote:
> > > 
> > >> Ravi Prasad wrote:
> > >>> Hi all,
> > >>>
> > >>> My need - Low power multihop for CC2420 (with
> > >>> Atmega128 mcu i.e micaz)..
> > >>>
> > >>>
> > >>> Low power CC2420 is being asked so many times
> in
> > >> this
> > >>> list. I have been working on TinyOS1.x and in
> > that
> > >> low
> > >>> power CC2420 was not really available.
> > >>>
> > >>> Now I have switched to TinyOS2.x and I know
> that
> > >> there
> > >>> is a LPL implementation of CC2420. But it
> seems
> > >> that
> > >>> is for a Star network topology & not used in
> any
> > >>> multihop routing protocol. Am I right??
> > >>>   
> > >> The CC2420 LPL in 2.x works for arbitrary
> > >> topologies.
> > >>
> > >> Phil
> > >>
> > > 
> > > 
> > > 
> > >        
> > >
> >
>
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> > 
> 
> 
> 
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