Ultra low power short range RF

I need to find RF components for a battery-powered (slave)
device that needs to do wireless communication. The master
device is not battery-powered and may consume more power.

My preliminary specs for slave are:
-continuous average current consumption <100uA
-communication speed is not an issue
-wakeup time for slave when master sends enquiry <50 ms
-data is not received/sent very often (couple of small packets/minute max)
 so current consumption while doing RX/TX is not that critical
-communication range VERY short (max AND min about 2-3 meters)

I'm more or less tied (mentally) with AVR, so I'm looking for
a companion for AVR controller.

I have found couple of options, one of them being Xemics XE1209.
Anyone has experienced a design with this one?

ANY ideas are welcome.

    Pygmi

look at AT86RF401, it is a transmitter with an AVR in the same chip


"Pygmi" <bronco_castor@hotmail.com> wrote in message
news:wYbSb.691$Sg6.577@read3.inet.fi...
> I need to find RF components for a battery-powered (slave)
> device that needs to do wireless communication. The master
> device is not battery-powered and may consume more power.
>
> My preliminary specs for slave are:
> -continuous average current consumption <100uA
> -communication speed is not an issue
> -wakeup time for slave when master sends enquiry <50 ms
> -data is not received/sent very often (couple of small packets/minute max)
>  so current consumption while doing RX/TX is not that critical
> -communication range VERY short (max AND min about 2-3 meters)
>
> I'm more or less tied (mentally) with AVR, so I'm looking for
> a companion for AVR controller.
>
> I have found couple of options, one of them being Xemics XE1209.
> Anyone has experienced a design with this one?
>
> ANY ideas are welcome.
>
>     Pygmi
>
>

Yes, it i sinteresting, but I just noticed that I forgot to clearly state
communication needs to by two-way...so I'll need transceivers.

The AT86RF211 on the other hand might be a choice...just need to
check the wakeup functionality.

Xemics XE1209 for example can be set to "partilly sleeping", woken by
carrier detection.
Another on might be transceivers that have built-in sleep cycles.
The <50 ms wakeup might however be a problem.

Pygmi

"Pierre de Vos" <pierre.devos@webmail.co.za> wrote in message
news:40196e94.0@news1.mweb.co.za...
> look at AT86RF401, it is a transmitter with an AVR in the same chip
>
>
> "Pygmi" <bronco_castor@hotmail.com> wrote in message
> news:wYbSb.691$Sg6.577@read3.inet.fi...
> > I need to find RF components for a battery-powered (slave)
> > device that needs to do wireless communication. The master
> > device is not battery-powered and may consume more power.
> >
> > My preliminary specs for slave are:
> > -continuous average current consumption <100uA
> > -communication speed is not an issue
> > -wakeup time for slave when master sends enquiry <50 ms
> > -data is not received/sent very often (couple of small packets/minute
max)
> >  so current consumption while doing RX/TX is not that critical
> > -communication range VERY short (max AND min about 2-3 meters)
> >
> > I'm more or less tied (mentally) with AVR, so I'm looking for
> > a companion for AVR controller.
> >
> > I have found couple of options, one of them being Xemics XE1209.
> > Anyone has experienced a design with this one?
> >
> > ANY ideas are welcome.
> >
> >     Pygmi
> >

One more thing...
What is the situation with this "Zigbee" standard.
Chips/products available?

    Pygmi

"Pygmi" <bronco_castor@hotmail.com> wrote in message
news:qyeSb.1121$Sg6.636@read3.inet.fi...
> Yes, it i sinteresting, but I just noticed that I forgot to clearly state
> communication needs to by two-way...so I'll need transceivers.
>
> The AT86RF211 on the other hand might be a choice...just need to
> check the wakeup functionality.
>
> Xemics XE1209 for example can be set to "partilly sleeping", woken by
> carrier detection.
> Another on might be transceivers that have built-in sleep cycles.
> The <50 ms wakeup might however be a problem.
>
> Pygmi
>
> "Pierre de Vos" <pierre.devos@webmail.co.za> wrote in message
> news:40196e94.0@news1.mweb.co.za...
> > look at AT86RF401, it is a transmitter with an AVR in the same chip
> >
> >
> > "Pygmi" <bronco_castor@hotmail.com> wrote in message
> > news:wYbSb.691$Sg6.577@read3.inet.fi...
> > > I need to find RF components for a battery-powered (slave)
> > > device that needs to do wireless communication. The master
> > > device is not battery-powered and may consume more power.
> > >
> > > My preliminary specs for slave are:
> > > -continuous average current consumption <100uA
> > > -communication speed is not an issue
> > > -wakeup time for slave when master sends enquiry <50 ms
> > > -data is not received/sent very often (couple of small packets/minute
> max)
> > >  so current consumption while doing RX/TX is not that critical
> > > -communication range VERY short (max AND min about 2-3 meters)
> > >
> > > I'm more or less tied (mentally) with AVR, so I'm looking for
> > > a companion for AVR controller.
> > >
> > > I have found couple of options, one of them being Xemics XE1209.
> > > Anyone has experienced a design with this one?
> > >
> > > ANY ideas are welcome.
> > >
> > >     Pygmi
> > >
>
>

"Pygmi" <bronco_castor@hotmail.com> wrote in message
news:wYbSb.691$Sg6.577@read3.inet.fi...
> I need to find RF components for a battery-powered (slave)
> device that needs to do wireless communication. The master
> device is not battery-powered and may consume more power.
>
> My preliminary specs for slave are:
> -continuous average current consumption <100uA
> -communication speed is not an issue
> -wakeup time for slave when master sends enquiry <50 ms
> -data is not received/sent very often (couple of small packets/minute max)
>  so current consumption while doing RX/TX is not that critical
> -communication range VERY short (max AND min about 2-3 meters)
>
> I'm more or less tied (mentally) with AVR, so I'm looking for
> a companion for AVR controller.
>
> I have found couple of options, one of them being Xemics XE1209.
> Anyone has experienced a design with this one?
>
> ANY ideas are welcome.
>
>     Pygmi
>
>

Nordic VLSI nRF2401 (1uA sleep, 18mA while active)
http://www.nvlsi.no
If you want to take advantage of the version with integrated micro
controller (nRF24E1 not an AVR though;-) you will have a single chip
solution that runs off 1.9V - 3.6V (directly from 2 AAA or AA;-)
Both are easy to use  as they have most of the RF "tidbits" integrated.

With the power budget you have I would rather look into redefining the
master/slave functionality:
The mains powered unit default is receive mode, the battery powered unit
sends a message either every (x)seconds or when a change in status appear.
The battery powered unit then awaits an acknowledge within a set time
window, if noACK  received, it will retransmit.
With an ACK it will know that message transaction is complete and go back
into sleep.

If the Master is to "wake up" the batterypower unit, this unit must be in a
mode where the receiver will be able to detect that the master wants to
talk, (more than your 100uA).You will need a fairly accurate RTC (or
similar) for a power effective "time mulitiplexing" system.

HTH

-- 
----
Morten
Raider of the Lost Electron

Raider of the Lost Electron wrote:
> With the power budget you have I would rather look
> into redefining the master/slave functionality:

A local company is doing something similar for asset tracking - they've
got a PIC-based keyfob module that'll transmit for >5 years on a single
coin cell.  Wakes up every minute or so.

Hi,

Interesting chips, although not what I'm looking for right now.
I couldn't find how they would wakeup by themselves from
RF-signal.
And yes, unfortunately the master really needs to wake up the slave.
This is possible at least with
-Xemics XE1209 having mode where it is woke up by carrier
  (takes few ms)
-one Aurel transceiver, having RX current < 100 uA!
So I really need the RF to wake up the system, one way or another.
This means the uC too, so that I can keep it sleeping.

AND I forgot something from my first "spec"
It is not just:
"wakeup time for slave when master sends enquiry <50 ms"
It is really wakeup, RX (few bytes), RX-TX round delay and
TX (few bytes)
And hopefully decent TX-RX turn around delay as well....

Any timed solution is NOT possible, as the devices are not
on fixed position. RFID-kind of hardware would do the trick, but
the price tag for those devices is way beyond reach...

Pygmi

"Raider of the Lost Electron" <invalid@spam.no> wrote in message
news:z1oSb.440$_c4.5559@news4.e.nsc.no...
>
> "Pygmi" <bronco_castor@hotmail.com> wrote in message
> news:wYbSb.691$Sg6.577@read3.inet.fi...
> > I need to find RF components for a battery-powered (slave)
> > device that needs to do wireless communication. The master
> > device is not battery-powered and may consume more power.
> >
> > My preliminary specs for slave are:
> > -continuous average current consumption <100uA
> > -communication speed is not an issue
> > -wakeup time for slave when master sends enquiry <50 ms
> > -data is not received/sent very often (couple of small packets/minute
max)
> >  so current consumption while doing RX/TX is not that critical
> > -communication range VERY short (max AND min about 2-3 meters)
> >
> > I'm more or less tied (mentally) with AVR, so I'm looking for
> > a companion for AVR controller.
> >
> > I have found couple of options, one of them being Xemics XE1209.
> > Anyone has experienced a design with this one?
> >
> > ANY ideas are welcome.
> >
> >     Pygmi
> >
> >
>
> Nordic VLSI nRF2401 (1uA sleep, 18mA while active)
> http://www.nvlsi.no
> If you want to take advantage of the version with integrated micro
> controller (nRF24E1 not an AVR though;-) you will have a single chip
> solution that runs off 1.9V - 3.6V (directly from 2 AAA or AA;-)
> Both are easy to use  as they have most of the RF "tidbits" integrated.
>
> With the power budget you have I would rather look into redefining the
> master/slave functionality:
> The mains powered unit default is receive mode, the battery powered unit
> sends a message either every (x)seconds or when a change in status appear.
> The battery powered unit then awaits an acknowledge within a set time
> window, if noACK  received, it will retransmit.
> With an ACK it will know that message transaction is complete and go back
> into sleep.
>
> If the Master is to "wake up" the batterypower unit, this unit must be in
a
> mode where the receiver will be able to detect that the master wants to
> talk, (more than your 100uA).You will need a fairly accurate RTC (or
> similar) for a power effective "time mulitiplexing" system.
>
> HTH
>
> -- 
> ----
> Morten
> Raider of the Lost Electron
>
>
>
>

"Pygmi" <bronco_castor@hotmail.com> wrote in message
news:J0wSb.533$K6.293@read3.inet.fi...
> Hi,
>
> Interesting chips, although not what I'm looking for right now.
> I couldn't find how they would wakeup by themselves from
> RF-signal.
> And yes, unfortunately the master really needs to wake up the slave.
> This is possible at least with
> -Xemics XE1209 having mode where it is woke up by carrier
>   (takes few ms)
> -one Aurel transceiver, having RX current < 100 uA!
> So I really need the RF to wake up the system, one way or another.
> This means the uC too, so that I can keep it sleeping.
>
> AND I forgot something from my first "spec"
> It is not just:
> "wakeup time for slave when master sends enquiry <50 ms"
> It is really wakeup, RX (few bytes), RX-TX round delay and
> TX (few bytes)
> And hopefully decent TX-RX turn around delay as well....
>
> Any timed solution is NOT possible, as the devices are not
> on fixed position. RFID-kind of hardware would do the trick, but
> the price tag for those devices is way beyond reach...
>
> Pygmi
>

Ah,
If the Xemics and/or Aurel chips can give you the <50ms turn around time you
require, then absolutely go for one of these.
If not; do you have room in your budget for a combination of a low-power
receiver (the Aurel or Xemics or similar) and a high-speed transceiver with
short enough wakeup and turn around time? -


-- 
----
Morten
Raider of the Lost Electron

"Raider of the Lost Electron" <invalid@spam.no> wrote in message
news:H73Tb.862$rj4.12729@news2.e.nsc.no...
>
> "Pygmi" <bronco_castor@hotmail.com> wrote in message
> news:J0wSb.533$K6.293@read3.inet.fi...
> > Hi,
> >
> > Interesting chips, although not what I'm looking for right now.
> > I couldn't find how they would wakeup by themselves from
> > RF-signal.
> > And yes, unfortunately the master really needs to wake up the slave.
> > This is possible at least with
> > -Xemics XE1209 having mode where it is woke up by carrier
> >   (takes few ms)
> > -one Aurel transceiver, having RX current < 100 uA!
> > So I really need the RF to wake up the system, one way or another.
> > This means the uC too, so that I can keep it sleeping.
> >
> > AND I forgot something from my first "spec"
> > It is not just:
> > "wakeup time for slave when master sends enquiry <50 ms"
> > It is really wakeup, RX (few bytes), RX-TX round delay and
> > TX (few bytes)
> > And hopefully decent TX-RX turn around delay as well....
> >
> > Any timed solution is NOT possible, as the devices are not
> > on fixed position. RFID-kind of hardware would do the trick, but
> > the price tag for those devices is way beyond reach...
> >
> > Pygmi
> >
>
> Ah,
> If the Xemics and/or Aurel chips can give you the <50ms turn around time
you
> require, then absolutely go for one of these.
> If not; do you have room in your budget for a combination of a low-power
> receiver (the Aurel or Xemics or similar) and a high-speed transceiver
with
> short enough wakeup and turn around time? -
>
>
> -- 
> ----
> Morten
> Raider of the Lost Electron
>
>
>

The Aurel for example has a TX-RX turn around around 500 ms!!
On the other hand current drawn by Aurel inRX-mode is less than
that of  Xemics in CD detect mode.... And Xemics max. range with
considerable current draw in TX is about 3 m. So,  these are close,
and I guess I could go with one of these, but... I pretty sure there is
somewhere behind the corner a chip that fulfills all my needs...just
can't find it.

Your idea of having receiver and transmitter separately is one
option, I have thought about that too. But in order to make this
as simple as possible I would like to find two chip solution;
AVR + transceiver..

For example Atmel AT86RF211 has "wake-up" mode, but it's
cyclical wake-up, not continous monitoring of CD/data...
One of these days, I will find what I need or the solution for my
application is out date...well, either of these will stop the search...

   Pygmi

"Pygmi" <bronco_castor@hotmail.com> wrote in message news:<NJeSb.1126$Sg6.389@read3.inet.fi>...
> One more thing...
> What is the situation with this "Zigbee" standard.
> Chips/products available?

Zigbee is still in development, however the underlying RF standard
IEEE 802.15.4 is complete.

CompXs (http://www.compxs.com) are selling development systems.

Cheers,
JonB