Polar cr*p



Claes

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Jul 5, 2004
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Hi, gotten back to sweden and using my polar 725 here for the first time. Boy, it is so sensitive to "high voltage" lines. My data is completely unusable. What about HR 225 and speeds around 140k for over 2.5k continuous? My old polar, ancient one, was not this sensitive. I thought these new ones were supposed to be better in that regard, with some unique features in that regard. Cr*p is what it is, unless I have f*cked up. Grr.
 
D

DaveB

Guest
Claes wrote:
> Hi, gotten back to sweden and using my polar 725 here for the first
> time. Boy, it is so sensitive to "high voltage" lines. My data is
> completely unusable. What about HR 225 and speeds around 140k for over
> 2.5k continuous? My old polar, ancient one, was not this sensitive. I
> thought these new ones were supposed to be better in that regard, with
> some unique features in that regard. Cr*p is what it is, unless I have
> f*cked up. Grr.
>
>


I've got an old one Claes and I see the same thing. Tramlines, high
voltage power lines, and the local auto electrican van all have he same
impact.

daveB
 

Claes

New Member
Jul 5, 2004
532
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0
DaveB said:
Claes wrote:
> Hi, gotten back to sweden and using my polar 725 here for the first
> time. Boy, it is so sensitive to "high voltage" lines. My data is
> completely unusable. What about HR 225 and speeds around 140k for over
> 2.5k continuous? My old polar, ancient one, was not this sensitive. I
> thought these new ones were supposed to be better in that regard, with
> some unique features in that regard. Cr*p is what it is, unless I have
> f*cked up. Grr.
>
>


I've got an old one Claes and I see the same thing. Tramlines, high
voltage power lines, and the local auto electrican van all have he same
impact.

daveB
Mmm, I do remember having some problems, but this is the same route, on the other hand it is like 10 years ago, so maybe they have more powerlines or something. Anyhow, it is annoying, because the data becomes complete mumbo jumbo. Thanx anyhow, good luck with your tris. I am trying to find some swiw cycle events, since I am not allowed to run, but no luck. Maybe I have to go to a tri, and then just not finish the run.
 
S

Stuart Lamble

Guest
On 2006-07-24, dtmeister <[email protected]> wrote:
> I'd imagine if it were a true digital checksummed data transmission, it
> would not record bogus data. You'd still get data dropouts due to
> external high power RF interferance, but I'd prefer 0 data (it could do
> some interpolation for a while though) than the weird 220bpm and 120km/h
> spikes I see sometimes.


The other question is whether the RF interference is interfering with
the data gathering, or the data transmission. If the latter, then yes,
checksummed data would resolve it. If the former, then you're SOL.

Anybody have a HR monitor that doesn't transmit data to a physically
separated unit that could be used for testing this?

> I'm not sure why they don't already do that? Maybe battery life issues?


Battery life issues wouldn't be great. Maybe 1% lossage ... hardly worth
bothering about (especially if you're on a rechargeable unit.)

--
My Usenet From: address now expires after two weeks. If you email me, and
the mail bounces, try changing the bit before the "@" to "usenet".
 
D

dtmeister

Guest
Stuart Lamble <[email protected]> wrote:
> On 2006-07-24, dtmeister <[email protected]> wrote:
>> I'd imagine if it were a true digital checksummed data transmission, it
>> would not record bogus data. You'd still get data dropouts due to
>> external high power RF interferance, but I'd prefer 0 data (it could do
>> some interpolation for a while though) than the weird 220bpm and 120km/h
>> spikes I see sometimes.

>
> The other question is whether the RF interference is interfering with
> the data gathering, or the data transmission. If the latter, then yes,
> checksummed data would resolve it. If the former, then you're SOL.


I'd suggest is 99% the latter. Whilst I could imagine a small chance
that EMI might mess with the strap's data collection, the wheel and
cadence sensors use simple magnet/reed switch arrangement. It's
mechanical, and unless you ride in an MRI machine, you should be
okay. Yet I see bogus data equally from strap and speed sensors. Yeah
yeah, with sufficient interference, you could still collect garbage
from those, but I'd suggest it's a not a real world issue.

Anyway, if you can trust your RF transmission absolutely, you can still
do much to throw away stupid data collection. All these problems have
been adequately solved long ago. Think aircraft. It's kind of critical
to trust certain remote measurements. At a cost of course. If 100% error
free HRM data is $4000, I'll stick with what I've got.

(Wonders if's he's covered off all possible nit picks that Stuart might
come back with. Probably not. :)) )

--
..dt
 

Claes

New Member
Jul 5, 2004
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dtmeister said:
Stuart Lamble <[email protected]> wrote:
> On 2006-07-24, dtmeister <[email protected]> wrote:
>> I'd imagine if it were a true digital checksummed data transmission, it
>> would not record bogus data. You'd still get data dropouts due to
>> external high power RF interferance, but I'd prefer 0 data (it could do
>> some interpolation for a while though) than the weird 220bpm and 120km/h
>> spikes I see sometimes.

>
> The other question is whether the RF interference is interfering with
> the data gathering, or the data transmission. If the latter, then yes,
> checksummed data would resolve it. If the former, then you're SOL.


I'd suggest is 99% the latter. Whilst I could imagine a small chance
that EMI might mess with the strap's data collection, the wheel and
cadence sensors use simple magnet/reed switch arrangement. It's
mechanical, and unless you ride in an MRI machine, you should be
okay. Yet I see bogus data equally from strap and speed sensors. Yeah
yeah, with sufficient interference, you could still collect garbage
from those, but I'd suggest it's a not a real world issue.

Anyway, if you can trust your RF transmission absolutely, you can still
do much to throw away stupid data collection. All these problems have
been adequately solved long ago. Think aircraft. It's kind of critical
to trust certain remote measurements. At a cost of course. If 100% error
free HRM data is $4000, I'll stick with what I've got.

(Wonders if's he's covered off all possible nit picks that Stuart might
come back with. Probably not. :)) )

--
..dt
I'd easily buy a "strap" to connect my strap with the polar device, then no interference while on the bike.

On one part of the ride, I am riding with the powlines from a train, 10 meters away, at wheel height, but there is a concrete wall, less than a metre high. So, the interference does not mess with the speedo, but the HR goes awol.
So funny though, sometimes HR maxes out, mostly, sometimes it goes down to 0, that is when I am really worried. :) Same with speed.
 

Claes

New Member
Jul 5, 2004
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Claes said:
I'd easily buy a "strap" to connect my strap with the polar device, then no interference while on the bike.

On one part of the ride, I am riding with the powlines from a train, 10 meters away, at wheel height, but there is a concrete wall, less than a metre high. So, the interference does not mess with the speedo, but the HR goes awol.
So funny though, sometimes HR maxes out, mostly, sometimes it goes down to 0, that is when I am really worried. :) Same with speed.
Just went out and bought a sigma 1100, so at least I can get accurate average and max speed. The max speed is very important, as all BR riders know. :)

So now 725 left of stem on bar, 1100 on stem, and light when so necessary, right of stem on the bar. Starts to look silly really, then two sensors at the fork, two magnets in the wheel. Hmm, silly is the word.
 

suzyj

New Member
Mar 22, 2004
704
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0
Claes wrote:

> Hi, gotten back to sweden and using my polar 725 here for
> the first time. Boy, it is so sensitive to "high voltage" lines. My
> data is completely unusable.

It's little wonder. Looking at the
Polar patent, they use pretty crude audio frequency inductive coupling between the transmitter belt and display. It's asking for trouble. I guess they do that to keep the range down, so that the belts don't interfere with one another. I reckon it's about time someone developed an open-standard HR/computer/cadence/whatever protocol, based on something like bluetooth or zigbee, that was designed to be robust.

Cheers,

Suzy (RF engineer)
 
S

Stuart Lamble

Guest
On 2006-07-25, suzyj <[email protected]> wrote:
> I reckon it's about time someone developed an
> open-standard HR/computer/cadence/whatever protocol, based on something
> like bluetooth or zigbee, that was designed to be robust.


*snort*

And do you *really* expect Polar, and other manufacturers, to use that
protocol? Having their own "private" system is an advantage: you're
locked into their products, and can't buy replacement parts if something
breaks from another manufacturer.

--
My Usenet From: address now expires after two weeks. If you email me, and
the mail bounces, try changing the bit before the "@" to "usenet".
 

Claes

New Member
Jul 5, 2004
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Stuart Lamble said:
On 2006-07-25, suzyj <[email protected]> wrote:
> I reckon it's about time someone developed an
> open-standard HR/computer/cadence/whatever protocol, based on something
> like bluetooth or zigbee, that was designed to be robust.


*snort*

And do you *really* expect Polar, and other manufacturers, to use that
protocol? Having their own "private" system is an advantage: you're
locked into their products, and can't buy replacement parts if something
breaks from another manufacturer.

--
My Usenet From: address now expires after two weeks. If you email me, and
the mail bounces, try changing the bit before the "@" to "usenet".
Scrsw standard this and that, I just want something that works ok, in the environment it supposed to be used in. This is so bad I am about to sell it. Imagine, you buy a car, whenever you drive close to a powerline the speedo goes nuts. Oh, sorry office, my speedo was indicating zero so I increased the speed. Eh.
 
B

BrettS

Guest
Claes wrote:

> Stuart Lamble Wrote:
>
>>On 2006-07-25, suzyj <[email protected]>
>>wrote:
>>
>>>I reckon it's about time someone developed an
>>>open-standard HR/computer/cadence/whatever protocol, based on
>>>something like bluetooth or zigbee, that was designed to be robust.

>>
>>*snort*
>>
>>And do you *really* expect Polar, and other manufacturers, to use that
>>protocol? Having their own "private" system is an advantage: you're
>>locked into their products, and can't buy replacement parts if
>>something
>>breaks from another manufacturer.
>>

>
> Scrsw standard this and that, I just want something that works ok, in
> the environment it supposed to be used in. This is so bad I am about to
> sell it. Imagine, you buy a car, whenever you drive close to a powerline
> the speedo goes nuts. Oh, sorry office, my speedo was indicating zero so
> I increased the speed. Eh.
>


You want something that works al the time, then do what they do with
cars. Use wires. Problem solved.

Multifunctional, accurate, or portable. Pick any two.

--
BrettS
 
R

Random Data

Guest
On Wed, 26 Jul 2006 23:53:22 +1000, Claes wrote:

> If they can fix it, then polar should be able to fix it too, if the
> other have the same issue, well then it might just be hard and
> expensive to solve and then wire is the only option in that type of
> environment I guess.


You're not comparing apples with apples. With the computer you've got a
strong magnetic field closing a switch. This then triggers the sensor to
send a signal, which can be digitally encoded. That's still susceptible to
interference, but a lot more reliable. The electrical field has to be
quite ridiculous to make the sensor think the switch is closed - to the
point that you wouldn't want to be there (think just about touching the
high tension cables).

The HRM *strap* is the problem. It's got to pick out the very weak
electrical field caused by your heart pumping. If there's much electrical
interference floating about it can't do that reliably. You could
conceivably shield the strap, but that'd make it weigh noticeably more.

--
Dave Hughes | [email protected]
A General Manager who was channeling Captain Bligh only without the
competent seamanship - Patrick R. Wade.
 

Claes

New Member
Jul 5, 2004
532
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BrettS said:
You want something that works al the time, then do what they do with
cars. Use wires. Problem solved.

Multifunctional, accurate, or portable. Pick any two.

--
BrettS
I reckon that is a lame answer. They sell the polar as a HR with cycling
functions, then you would expect it to work well in the environment we normally cycle in, no? Sure wire works, that is what I have put on the bike, but I still reckon the polar one should work better, or simply be more resilient against interference.

Here is an interesting question.

Anyone have a wireless speedo sensor to a normal cycling computer, not a polar one. Like a sigma or vdo or cateye.
How do they work under/near powerlines, do they get the same "fit" or do they cope well wit it and display accurate speed?

If they can fix it, then polar should be able to fix it too, if the other have the same issue, well then it might just be hard and expensive to solve and then wire is the only option in that type of environment I guess.
 

suzyj

New Member
Mar 22, 2004
704
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0
Claes wrote:

> Anyone have a wireless speedo sensor to a normal cycling
> computer, not a polar one. Like a sigma or vdo or cateye.
>How do they work under/near powerlines, do they get the
> same "fit" or do they cope well wit it and display accurate
> speed?

I've used a VDO C10+ and a Sigmasport BC1200 with the wireless mount. Both are orders of magnitude more reliable than my Polar HR monitor. The only time my wireless speedos have registered incorrect data have been because the battery was going flat (or there was one time I leaned the bike up against a neon sign outside a shop, when my VDO speedo did ~120km/h).

My HR monitor, on the other hand, goes nuts whenever I ride under powerlines or near train tracks.

It *is* possible to make the transmission extremely reliable. You can use things like sequence numbers to cope with the occasional lost transmissions. The only problem with this is that the sensor then needs some smarts (more smarts than a simple switch sending a signal, at any rate), so it might cost a dollar or two more.

Cheers,

Suzy
 

endroll

New Member
Jul 6, 2005
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Claes said:
Hi, gotten back to sweden and using my polar 725 here for the first time. Boy, it is so sensitive to "high voltage" lines. My data is completely unusable. What about HR 225 and speeds around 140k for over 2.5k continuous? My old polar, ancient one, was not this sensitive. I thought these new ones were supposed to be better in that regard, with some unique features in that regard. Cr*p is what it is, unless I have f*cked up. Grr.
Hah!my HRM won't transmit/pick-up when too close to my bluetooth mobile.
 
T

Tamyka Bell

Guest
endroll wrote:
>
> Claes Wrote:
> > Hi, gotten back to sweden and using my polar 725 here for the first
> > time. Boy, it is so sensitive to "high voltage" lines. My data is
> > completely unusable. What about HR 225 and speeds around 140k for over
> > 2.5k continuous? My old polar, ancient one, was not this sensitive. I
> > thought these new ones were supposed to be better in that regard, with
> > some unique features in that regard. Cr*p is what it is, unless I have
> > f*cked up. Grr.

> Hah!my HRM won't transmit/pick-up when too close to my bluetooth
> mobile.


My HRM works under all conditions and does not suffer from interference.
1. Find pulse.
2. Count beats B over time period T (in seconds).
3. Convert to heart rate HR=60*B/T.

Tam
 
B

Bleve

Guest
Tamyka Bell wrote:
> endroll wrote:
> >
> > Claes Wrote:
> > > Hi, gotten back to sweden and using my polar 725 here for the first
> > > time. Boy, it is so sensitive to "high voltage" lines. My data is
> > > completely unusable. What about HR 225 and speeds around 140k for over
> > > 2.5k continuous? My old polar, ancient one, was not this sensitive. I
> > > thought these new ones were supposed to be better in that regard, with
> > > some unique features in that regard. Cr*p is what it is, unless I have
> > > f*cked up. Grr.

> > Hah!my HRM won't transmit/pick-up when too close to my bluetooth
> > mobile.

>
> My HRM works under all conditions and does not suffer from interference.
> 1. Find pulse.
> 2. Count beats B over time period T (in seconds).
> 3. Convert to heart rate HR=60*B/T.


How well does it log intensity over 5s intervals for a 8 hour ride? :)


>
> Tam
 
T

Tamyka Bell

Guest
Bleve wrote:
>
> Tamyka Bell wrote:
> > endroll wrote:
> > >
> > > Claes Wrote:
> > > > Hi, gotten back to sweden and using my polar 725 here for the first
> > > > time. Boy, it is so sensitive to "high voltage" lines. My data is
> > > > completely unusable. What about HR 225 and speeds around 140k for over
> > > > 2.5k continuous? My old polar, ancient one, was not this sensitive. I
> > > > thought these new ones were supposed to be better in that regard, with
> > > > some unique features in that regard. Cr*p is what it is, unless I have
> > > > f*cked up. Grr.
> > > Hah!my HRM won't transmit/pick-up when too close to my bluetooth
> > > mobile.

> >
> > My HRM works under all conditions and does not suffer from interference.
> > 1. Find pulse.
> > 2. Count beats B over time period T (in seconds).
> > 3. Convert to heart rate HR=60*B/T.

>
> How well does it log intensity over 5s intervals for a 8 hour ride? :)


No worse than than the Polar HRM that Claes uses, apparently.

I made a wonderful discovery that I can predict my HR quite accurately
based on my current breathing pattern and stride rate, when running.
*sigh* I can breathe easy again, and not worry about chafing. (Yes, even
soft straps chafe. And yes the word is chafing, not chaffing.)

Tam
 

endroll

New Member
Jul 6, 2005
115
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0
Tamyka Bell said:
Bleve wrote:
>
> Tamyka Bell wrote:
> > endroll wrote:
> > >
> > > Claes Wrote:
> > > > Hi, gotten back to sweden and using my polar 725 here for the first
> > > > time. Boy, it is so sensitive to "high voltage" lines. My data is
> > > > completely unusable. What about HR 225 and speeds around 140k for over
> > > > 2.5k continuous? My old polar, ancient one, was not this sensitive. I
> > > > thought these new ones were supposed to be better in that regard, with
> > > > some unique features in that regard. Cr*p is what it is, unless I have
> > > > f*cked up. Grr.
> > > Hah!my HRM won't transmit/pick-up when too close to my bluetooth
> > > mobile.

> >
> > My HRM works under all conditions and does not suffer from interference.
> > 1. Find pulse.
> > 2. Count beats B over time period T (in seconds).
> > 3. Convert to heart rate HR=60*B/T.


This is my version at 70kph while descending:
1 take one hand off handlebar
2 apply to opposite wrist or to side of neck
3 palpate for pulse
4 find pulse over 15 seconds for some relative accuracy
5 multiply by 4
6 feel ambulance officer palpate your wrist, neck, groin or other point of reference
7 wonder what the hell happened
8 hopefully palpated HR is not 0
:D
 
B

BrettS

Guest
Claes wrote:

> BrettS Wrote:
>
>>You want something that works al the time, then do what they do with
>>cars. Use wires. Problem solved.
>>
>>Multifunctional, accurate, or portable. Pick any two.
>>
>>--
>>BrettS

>
> I reckon that is a lame answer.


No, you were comparing your Polar to a car's speedo and wondering why
the car doesn't have the same problems. It's because they don't use
wireless connections.


> They sell the polar as a HR with cycling
> functions, then you would expect it to work well in the environment we
> normally cycle in, no? Sure wire works, that is what I have put on the
> bike, but I still reckon the polar one should work better, or simply be
> more resilient against interference.


Sure, but remember there are competing priorities, one of which is
battery life. Should they use a communication method that consumes more
power *all* the time just to protect against something that occurs a
very small percentage of the time.

>
> Here is an interesting question.
>
> Anyone have a wireless speedo sensor to a normal cycling computer, not
> a polar one. Like a sigma or vdo or cateye.
> How do they work under/near powerlines, do they get the same "fit" or
> do they cope well wit it and display accurate speed?


Anecdotally, I understand that wireless speedos sometimes read 199km/h
due to the right interference.

--
BrettS