Spoke sensor for bicycle

Dimiter_Popoff <dp@tgi-sci.com> wrote:
> I started cycling again (used to as a kid...) some 4 years ago.
> And while I know there are plenty of super cheap "bicycle computers"
> I have been thinking of making my own.

Can any of the commercially available bicycle odometer/speedometers
use the output from a hub dynamo for measuring distance/speed? The
Shimano DH3N72 gives, I think, 14 cycles per turn. Using a diode to
half-wave rectify it would make 7 pulses per turn. 

Thanks for reading,

bob prohaska


> Thus so far 4 years no speed/mileage indicator for me, obviously.
> While this may likely remain the case forever I am still thinking
> about it - not the obvious things like the MCU, display etc., just
> the rotation sensor. They all use a magnet placed somewhere on one
> of the wheels and some sensor, I have used a Hall sensor for
> pretty precise positioning of the rotor of our TLD reader etc.,
> but I only still keep on thinking of making the thing because I
> imagine it sensing just the spokes, i.e. making some inductive sensor.
> 
> I know what I will try out etc., I may even get to designing one before
> the millennium is over but well, these thoughts seem to be on topic and
> I am sure there are people with more experience making inductive
> sensors than I have.
> 
> 
> ======================================================
> Dimiter Popoff, TGI             http://www.tgi-sci.com
> ======================================================
> http://www.flickr.com/photos/didi_tgi/
> 
> 
> 
> 
> 
> 
> 
> 
> 

On Wed, 15 Jun 2022 06:52:43 GMT, Jan Panteltje
<pNaonStpealmtje@yahoo.com> wrote:

>On a sunny day (Tue, 14 Jun 2022 17:56:50 -0400) it happened Joe Gwinn
><joegwinn@comcast.net> wrote in <4a0iahhpmhi9ocv7ig0k1nidjn95mqbbg1@4ax.com>:
>
>>Well, there is also Wiegand-wire sensors:
>>
>>.<https://en.wikipedia.org/wiki/Wiegand_effect>
>>
>>.<https://en.wikipedia.org/wiki/Wiegand_Sensor>
>>
>>But as others have noted, the spokes may be non-magnetic.  This can be
>>solved by adding a bit of zinc-plated mild steel tubing (automotive
>>brake line) glued to at least one spoke with a silicon rubber
>>adhesive.  The spoke would pass through an inch of tube, with silicon
>> rubber filling the gap between tube and spoke.
>>
>>Joe Gwinn
>
>Just thinking, use a camera looking down
>The speed can be derived from the moving pattern it sees
>Almost like a computah mouse...

Need to also block the view beyond those spokes, or nearby scenery can
affect speed readings.

Joe Gwinn

On 6/15/2022 6:50 AM, rbowman wrote:
> On 06/15/2022 12:02 AM, Don Y wrote:
>> Things like bicycle, Segway, one-wheels, etc. come to mind.  But, none
>> have really checked all the boxes (e.g., carrying a bag of groceries
>> on a bike or Segway is really not ideal).
> 
> There are quite a few cargo bikes or if you already have a bike, trailers. A 
> friend has a BOB Yak that worked out well. It's easy to disconnect if you don't 
> need it and the single wheel means it tracks on the same path as the bike if 
> you ride single track.

Bikes won't work well as I'd want to be able to take the "shortcuts"
over dirt/gravel/grass.  Something more "ATV-ish" is called for.
Hence the Segway option.  (The Segway "egg" looks do-able)

[I can save half a mile on the trip to the library using "walkable"
shortcuts]

I also have to be wary of the laws regarding where you can operate
said "conveyance".  E.g., I don't think bicycles are allowed on sidewalks.
And, the rules for ebikes might be different.

OTOH, the wheelchair probably squeaks through the legalities in the
most permissive ways.   (and, I don't think there is anything that
says the rider must NEED the wheelchair... just like the driver of
a vehicle with disabled plates needn't be disabled!)

The gas-powered genset might run afoul of "something", though...

> The low cost solution would be looking for one of those child trailers at a 
> yard sale.
> 
> There are also bike panniers but you wind up repacking the groceries to get 
> everything to fit. Two wheeled grocery shopping on either a bicycle or 
> motorcycle tends to limit impulse purchases.

Years ago, I tried the bike approach.  Driving on the roads is just too
perilous.  Having to cross 4 lanes of 45+MPH traffic several times on each
"short trip" left my nerves jangled.

On Tue, 14 Jun 2022 20:03:12 -0600, rbowman <bowman@montana.com>
wrote:

>On 06/14/2022 06:22 PM, Don Y wrote:
>> The biggest win is it gets you away from the wheel.  E.g., you could
>> affix a
>> bar magnet to the end of the cable-in-cable and detect it's rotation (to
>> whatever extent you desire) as well as using its motion to generate *power*
>> for the circuit (esp with the ultra low power technologies now available;
>> think about the tire-rubbing generators that used to power headlamps...)
>
>What a wondrous invention they were... All that aggro for a one 
>candlepower headlamp. 

I had one of those generators as well.  The drag from that generator
was quite significant.  And I could see better by ambient (street
lamp) light.  I went to using an ordinary flashlight to warn cars of
my presence.


>    Somehow I associate those with the Sturmey-Archer 
>three speed hubs.

A blast from the past.  I got very good at adjusting and repairing
them.  

It took me a year to figure out why, when pedaling strongly the foot
crank would abruptly come loose, free-rotate a half-turn or so, and
then reconnect, as if nothing had happened.

It turned out that the bronze C-ring that expanded against the inside
of the hub to brake the wheel had become worn enough to allow the four
drive pins to pull out of their sockets under heavy load, rotate
sliding un till managing to drop back into the same sockets, clocked
but undamaged.  Replacing the C-ring solved the problem.

Sturmey-Archer still exists, and has all the old documentation online.

.<http://www.sturmey-archerheritage.com/index.php?page=history&type=technic&era=1>


>I suppose driving a generator that way is better than driving the 
>bicycle with a 26cc motor in a similar way:
>
>http://bumblebeebolton.com/front_instructions.html
>
>I thought the concept might have been relegated to the trash bin of 
>history but I've seen a similar design for a DIY low rent eBike.

I recall similar things from the 1960s as well.  Was never tempted.  I
bet they sounded like an infuriated bumblebee, only higher pitched.
And LOUD.

Joe Gwinn

On Wed, 15 Jun 2022 06:52:43 GMT, Jan Panteltje
<pNaonStpealmtje@yahoo.com> wrote:

>On a sunny day (Tue, 14 Jun 2022 17:56:50 -0400) it happened Joe Gwinn
><joegwinn@comcast.net> wrote in <4a0iahhpmhi9ocv7ig0k1nidjn95mqbbg1@4ax.com>:
>
>>Well, there is also Wiegand-wire sensors:
>>
>>.<https://en.wikipedia.org/wiki/Wiegand_effect>
>>
>>.<https://en.wikipedia.org/wiki/Wiegand_Sensor>
>>
>>But as others have noted, the spokes may be non-magnetic.  This can be
>>solved by adding a bit of zinc-plated mild steel tubing (automotive
>>brake line) glued to at least one spoke with a silicon rubber
>>adhesive.  The spoke would pass through an inch of tube, with silicon
>> rubber filling the gap between tube and spoke.
>>
>>Joe Gwinn
>
>Just thinking, use a camera looking down
>The speed can be derived from the moving pattern it sees
>Almost like a computah mouse...

Second answer:  Ignore spokes.  Looking down at the street surface
flying by?  How does this work on featureless concrete or tarred
blacktop?  Or a painted surface?

Or if it's raining or snowing?

Joe Gwinn

Joerg wrote:
> Dimiter_Popoff wrote:
>> I started cycling again (used to as a kid...) some 4 years ago.
>> And while I know there are plenty of super cheap "bicycle computers"
>> I have been thinking of making my own.
>> Thus so far 4 years no speed/mileage indicator for me, obviously.
>> While this may likely remain the case forever I am still thinking
>> about it - not the obvious things like the MCU, display etc., just
>> the rotation sensor. They all use a magnet placed somewhere on one
>> of the wheels and some sensor, I have used a Hall sensor for
>> pretty precise positioning of the rotor of our TLD reader etc.,
>> but I only still keep on thinking of making the thing because I
>> imagine it sensing just the spokes, i.e. making some inductive sensor.
>>
>
> There are at least two reasons for the magnet. One is that it triggers a
> reed contact on the other side. This allows the whole speedometer to not
> have to be turned off by hand for battery conservation. It simply does
> that on its own and when the reed switch changes state again it turns
> itself back on. So you can just park your bike and walk away. Well,
> maybe not in a large city because then it gets stolen.
>
> The second reason is that this system works down to very low speeds.
> There isn't actually a lower limit and it will still clock the miles
> correctly.
>
>
>> I know what I will try out etc., I may even get to designing one before
>> the millennium is over but well, these thoughts seem to be on topic and
>> I am sure there are people with more experience making inductive
>> sensors than I have.
>>
>
> I can already smell an engineer's solution coming up. Huge sensor,
> multiple bus cables, a laptop mounted to the handlebar ... :-)

My own mountain cycling takes place year around. Throughout the winter:

<https://crcomp.net/arts/spintale/winter.png>

as well as the summer:

<https://crcomp.net/arts/spintale/summer.png>

Here's a inverted perspective image of the outcrop show by the second 
picture. It's taken from the road's point-of-view. The outcrop is the 
smaller of the two shown. It appears to the left of the larger outcrop, 
on the left summit. The photo gives you an idea of the mountain trail's
inaccessibility:

<https://crcomp.net/arts/spintale/invert.png>

My MP3 mod makes spins so much more enjoyable these days:

<https://crcomp.net/mp3mod/index.php>

Anyhow, long story short, a cadence sensor would theoretically work
better than a speedometer, for me personally. And a GPS solution 
probably can't cadence count accurately.

As others already more-or-less mentioned, the industry tends to utilize 
spoke magnets:

<https://heavy.com/sports/top-best-speed-cadence-sensors-bike-garmin-edge-zwift-computer/>

The frames of some bicycles accommodate optional bolt-on sensors:
    
<https://www.dcrainmaker.com/2011/02/look-at-trekbontrager-frame-integrated.html>

Danke,

-- 
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

Addendum: My own links need to be read by me /before/ they're posted. It
seems GPS sensors replaced magnets.

Joerg wrote:
> Dimiter_Popoff wrote:
>> I started cycling again (used to as a kid...) some 4 years ago.
>> And while I know there are plenty of super cheap "bicycle computers"
>> I have been thinking of making my own.
>> Thus so far 4 years no speed/mileage indicator for me, obviously.
>> While this may likely remain the case forever I am still thinking
>> about it - not the obvious things like the MCU, display etc., just
>> the rotation sensor. They all use a magnet placed somewhere on one
>> of the wheels and some sensor, I have used a Hall sensor for
>> pretty precise positioning of the rotor of our TLD reader etc.,
>> but I only still keep on thinking of making the thing because I
>> imagine it sensing just the spokes, i.e. making some inductive sensor.
>>
>
> There are at least two reasons for the magnet. One is that it triggers a
> reed contact on the other side. This allows the whole speedometer to not
> have to be turned off by hand for battery conservation. It simply does
> that on its own and when the reed switch changes state again it turns
> itself back on. So you can just park your bike and walk away. Well,
> maybe not in a large city because then it gets stolen.
>
> The second reason is that this system works down to very low speeds.
> There isn't actually a lower limit and it will still clock the miles
> correctly.
>
>
>> I know what I will try out etc., I may even get to designing one before
>> the millennium is over but well, these thoughts seem to be on topic and
>> I am sure there are people with more experience making inductive
>> sensors than I have.
>>
>
> I can already smell an engineer's solution coming up. Huge sensor,
> multiple bus cables, a laptop mounted to the handlebar ... :-)

My own mountain cycling takes place year around. Throughout the winter:

<https://crcomp.net/arts/spintale/winter.png>

as well as the summer:

<https://crcomp.net/arts/spintale/summer.png>

Here's a inverted perspective image of the outcrop show by the second 
picture. It's taken from the road's point-of-view. The outcrop is the 
smaller of the two shown. It appears to the left of the larger outcrop, 
on the left summit. The photo gives you an idea of the mountain trail's
inaccessibility:

<https://crcomp.net/arts/spintale/invert.png>

My MP3 mod makes spins so much more enjoyable these days:

<https://crcomp.net/mp3mod/index.php>

Anyhow, long story short, here's 15 sensors:

<https://heavy.com/sports/top-best-speed-cadence-sensors-bike-garmin-edge-zwift-computer/>

The frames of some bicycles accommodate optional bolt-on sensors:
    
<https://www.dcrainmaker.com/2011/02/look-at-trekbontrager-frame-integrated.html>

Danke,

-- 
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

On Wednesday, June 15, 2022 at 11:46:09 AM UTC-4, Joe Gwinn wrote:
> On Wed, 15 Jun 2022 06:52:43 GMT, Jan Panteltje 
> <pNaonSt...@yahoo.com> wrote:
> >On a sunny day (Tue, 14 Jun 2022 17:56:50 -0400) it happened Joe Gwinn 
> ><joeg...@comcast.net> wrote in <4a0iahhpmhi9ocv7i...@4ax.com>: 
> > 
> >>Well, there is also Wiegand-wire sensors: 
> >> 
> >>.<https://en.wikipedia.org/wiki/Wiegand_effect> 
> >> 
> >>.<https://en.wikipedia.org/wiki/Wiegand_Sensor> 
> >> 
> >>But as others have noted, the spokes may be non-magnetic. This can be 
> >>solved by adding a bit of zinc-plated mild steel tubing (automotive 
> >>brake line) glued to at least one spoke with a silicon rubber 
> >>adhesive. The spoke would pass through an inch of tube, with silicon 
> >> rubber filling the gap between tube and spoke. 
> >> 
> >>Joe Gwinn 
> > 
> >Just thinking, use a camera looking down 
> >The speed can be derived from the moving pattern it sees 
> >Almost like a computah mouse...
> Second answer: Ignore spokes. Looking down at the street surface 
> flying by? How does this work on featureless concrete or tarred 
> blacktop? Or a painted surface? 
> 
> Or if it's raining or snowing? 

I once had a  mouse that would work on glass!  Images have a lot more information than you might think.  Nothing is completely uniform. 

-- 

Rick C.

-+- Get 1,000 miles of free Supercharging
-+- Tesla referral code - https://ts.la/richard11209 

On Wednesday, 15 June 2022 at 18:05:04 UTC+2, Ricky wrote:
> On Wednesday, June 15, 2022 at 11:46:09 AM UTC-4, Joe Gwinn wrote: 
> > On Wed, 15 Jun 2022 06:52:43 GMT, Jan Panteltje 
> > <pNaonSt...@yahoo.com> wrote: 
> > >On a sunny day (Tue, 14 Jun 2022 17:56:50 -0400) it happened Joe Gwinn 
> > ><joeg...@comcast.net> wrote in <4a0iahhpmhi9ocv7i...@4ax.com>: 
> > > 
> > >>Well, there is also Wiegand-wire sensors: 
> > >> 
> > >>.<https://en.wikipedia.org/wiki/Wiegand_effect> 
> > >> 
> > >>.<https://en.wikipedia.org/wiki/Wiegand_Sensor> 
> > >> 
> > >>But as others have noted, the spokes may be non-magnetic. This can be 
> > >>solved by adding a bit of zinc-plated mild steel tubing (automotive 
> > >>brake line) glued to at least one spoke with a silicon rubber 
> > >>adhesive. The spoke would pass through an inch of tube, with silicon 
> > >> rubber filling the gap between tube and spoke. 
> > >> 
> > >>Joe Gwinn 
> > > 
> > >Just thinking, use a camera looking down 
> > >The speed can be derived from the moving pattern it sees 
> > >Almost like a computah mouse... 
> > Second answer: Ignore spokes. Looking down at the street surface 
> > flying by? How does this work on featureless concrete or tarred 
> > blacktop? Or a painted surface? 
> > 
> > Or if it's raining or snowing?
> I once had a mouse that would work on glass! Images have a lot more information than you might think. Nothing is completely uniform. 
> 
> -- 
> 
> Rick C. 
> 
> -+- Get 1,000 miles of free Supercharging 
> -+- Tesla referral code - https://ts.la/richard11209
optical/laser mouse as movement sensor or local LIDAR is still a hot item, loved by developers.


GPS smartphones replaced old bike computers 10-15 years ago
and there is no return

Addendum: My own links need to be read by me /before/ they're posted. It
seems GPS sensors replaced magnets.

Addendum 2: It's unknown what role, if any, GPS plays with bicycle 
cadence/speedometer sensors. May your own Inet search discover reality,
as my own Inet searches for quick answers are now a thing of the past.

Joerg wrote:
> Dimiter_Popoff wrote:
>> I started cycling again (used to as a kid...) some 4 years ago.
>> And while I know there are plenty of super cheap "bicycle computers"
>> I have been thinking of making my own.
>> Thus so far 4 years no speed/mileage indicator for me, obviously.
>> While this may likely remain the case forever I am still thinking
>> about it - not the obvious things like the MCU, display etc., just
>> the rotation sensor. They all use a magnet placed somewhere on one
>> of the wheels and some sensor, I have used a Hall sensor for
>> pretty precise positioning of the rotor of our TLD reader etc.,
>> but I only still keep on thinking of making the thing because I
>> imagine it sensing just the spokes, i.e. making some inductive sensor.
>>
>
> There are at least two reasons for the magnet. One is that it triggers a
> reed contact on the other side. This allows the whole speedometer to not
> have to be turned off by hand for battery conservation. It simply does
> that on its own and when the reed switch changes state again it turns
> itself back on. So you can just park your bike and walk away. Well,
> maybe not in a large city because then it gets stolen.
>
> The second reason is that this system works down to very low speeds.
> There isn't actually a lower limit and it will still clock the miles
> correctly.
>
>
>> I know what I will try out etc., I may even get to designing one before
>> the millennium is over but well, these thoughts seem to be on topic and
>> I am sure there are people with more experience making inductive
>> sensors than I have.
>>
>
> I can already smell an engineer's solution coming up. Huge sensor,
> multiple bus cables, a laptop mounted to the handlebar ... :-)

My own mountain cycling takes place year around. Throughout the winter:

<https://crcomp.net/arts/spintale/winter.png>

as well as the summer:

<https://crcomp.net/arts/spintale/summer.png>

Here's a inverted perspective image of the outcrop show by the second 
picture. It's taken from the road's point-of-view. The outcrop is the 
smaller of the two shown. It appears to the left of the larger outcrop, 
on the left summit. The photo gives you an idea of the mountain trail's
inaccessibility:

<https://crcomp.net/arts/spintale/invert.png>

My MP3 mod makes spins so much more enjoyable these days:

<https://crcomp.net/mp3mod/index.php>

Anyhow, long story short, FWIW, here's a 15 sensors link returned on the
first page of an Inet search:

<https://heavy.com/sports/top-best-speed-cadence-sensors-bike-garmin-edge-zwift-computer/>

The frames of some bicycles accommodate optional bolt-on sensors:
    
<https://www.dcrainmaker.com/2011/02/look-at-trekbontrager-frame-integrated.html>

Danke,

-- 
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.