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.

On 6/15/2022 9:24 AM, Don wrote:
> 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.

GPS-based "distance traveled" figures tend to overestimate the
actual distance traveled. Even a beginner is taught to always
reference measurements from a common point (instead of stacking
measurement errors).

On a sunny day (Wed, 15 Jun 2022 11:45:56 -0400) it happened Joe Gwinn
<joegwinn@comcast.net> wrote in <dhvjahhi98bc6se5ft4rmphtc0co0kbq8b@4ax.com>:

>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?

Concrete is not that 'featureless' at all.
As to the software, if you look up any open source mpegX encoding (X for 1, 2, whatever have you these days)
you will see it, among other things, calculates a motion vector, remember using that long long time ago...
Given fixed frames per second (30 or 25 depending on where you are), lens angle and hight,
calibration would only take a short time.
I use my puter mice on a white table and it never had a problem.
Maybe shine a light or laser down to the ground.
Its just a possible solution, not saying its better than other ones, but fun for experimenting.

>Or if it's raining or snowing?

I do not go biking in weather like that, I look at the rain-rader here first for what's coming.

On 6/15/2022 12:29, Clive Arthur wrote:
> On 14/06/2022 18:09, Dimiter_Popoff wrote:
>
> <snipped>
>>
>> Hmmm, but will that work at really low speed (like when pushing the
>> bike uphill)? It is an idea to do it this way (I did not even know the
>> name of the method so the idea is more than welcome), yet what I was
>> thinking was more in the line of changing some oscillation frequency
>> (thus detecting the spokes also  "at DC").
>
> A former colleague used a clever method for an impeller type flow
> sensor.  He used a small unshielded inductor with a parallel capacitor
> connected to a PIC pin.  Set the pin to be an output, kick the LC with a
> pulse, then set the pin to be an input and count oscillations.  In air,
> you get a few counts, near metal, you get fewer counts.  I don't know
> details, but he was able to sample sufficiently quickly for it to work.
>
> My guess is that it wouldn't be practical over the clearance distance
> you'd need for a spoke, but it's a neat method.
>

The method is neat indeed. I think I could make that work, I'd say a 3mm
maximum distance from the spokes is achievable mechanically. Hmm. Might
not give up the idea yet after all. Especially after trying out so far
3 apps for the phone, each useless for one reason or another.

On Wednesday, 15 June 2022 at 18:39:57 UTC+2, Don Y wrote:
> On 6/15/2022 9:24 AM, Don wrote:
> > 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.
> GPS-based "distance traveled" figures tend to overestimate the
> actual distance traveled. Even a beginner is taught to always
> reference measurements from a common point (instead of stacking
> measurement errors).
you are not correct

you can easily switch GPS receiver in your smartphone into exact RTK GPS mode to get 20 cm accuracy

so bike computer is an ancient stuff, no more hot

On Wednesday, 15 June 2022 at 18:44:04 UTC+2, Jan Panteltje wrote:
> On a sunny day (Wed, 15 Jun 2022 11:45:56 -0400) it happened Joe Gwinn
> <joeg...@comcast.net> wrote in <dhvjahhi98bc6se5f...@4ax.com>:
> >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?
> Concrete is not that 'featureless' at all.
> As to the software, if you look up any open source mpegX encoding (X for 1, 2, whatever have you these days)
> you will see it, among other things, calculates a motion vector, remember using that long long time ago...
> Given fixed frames per second (30 or 25 depending on where you are), lens angle and hight,
> calibration would only take a short time.
> I use my puter mice on a white table and it never had a problem.
> Maybe shine a light or laser down to the ground.
> Its just a possible solution, not saying its better than other ones, but fun for experimenting.
> >Or if it's raining or snowing?
> I do not go biking in weather like that, I look at the rain-rader here first for what's coming.
excellent
laser/optical mouse can be easily turned into $10 3D LIDAR scanner

On 6/15/2022 9:02, Don Y wrote:
>......
>
> I've been looking for an "alternate" form of transportation for the
> little jaunts -- to the library, post office, etc.  Just a couple of
> miles, likely off-road.
>
> 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).

I manage to carry a 5-6 kg backpack biking from the nearby (4-5 km)
shops. And the way back is uphill (not dramatic though). If it is
reasonably flat in your area you will just need a backpack similar
to mine - Lucy gave it to me when I got the bike, she had used it
years ago when she was walking up the mountains. Very light but
strong enough.

>
> But, recently, I'm liking the idea of a small gas powered generator
> tucked in the battery compartment of my electric wheelchair (!).
> This would eliminate the maintenance issue of the batteries
> ($400/set) as well as increase the possible RELIABLE range of
> the chair.  (of course, you couldn't use it indoors but that's fine)
>
> Building on that idea, a gas powered Segway?  <grin> >

I have seen "normal" bicycles with a battery and some electric
motor... I was told the motor just helps you, they are made not
to move on their own, you have to pedal but you get assistance
(making life easier uphill I suppose). Some nonsense that, why
would I bike if I didn't want the exercise.

On 6/15/2022 10:01 AM, a a wrote:
> On Wednesday, 15 June 2022 at 18:39:57 UTC+2, Don Y wrote:
>> On 6/15/2022 9:24 AM, Don wrote:
>>> 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.
>> GPS-based "distance traveled" figures tend to overestimate the
>> actual distance traveled. Even a beginner is taught to always
>> reference measurements from a common point (instead of stacking
>> measurement errors).
> you are not correct
>
> you can easily switch GPS receiver in your smartphone into exact RTK GPS mode to get 20 cm accuracy

So, I can move 8 inches to the left of where I am and your app will tell me
that I've (1) moved, (2) which direction I've moved, (3) that it was 8 inches?

Wow, so you can RELY on having a good constellation available to you,
at all times, in all places? What world do YOU live in?

<https://www.dcrainmaker.com/2011/12/why-new-york-times-gps-running-article.html>

<https://spectrum.ieee.org/why_every_gps_overestimates_distance_traveled>

<http://gpsinformation.net/articles/tripdistanceerror.htm>

And, of course, your statement applies to ALL smartphones, right?

> so bike computer is an ancient stuff, no more hot

Joe Gwinn wrote:
> 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
>

Trying to keep any optical surface clean enough is a challenge. A
theremin would be a fun way to do it, if not necessarily the most practical.

Cheers

Phil Hobbs

On Wednesday, 15 June 2022 at 19:08:41 UTC+2, Dimiter Popoff wrote:
> On 6/15/2022 9:02, Don Y wrote:
> >......
> >
> > I've been looking for an "alternate" form of transportation for the
> > little jaunts -- to the library, post office, etc. Just a couple of
> > miles, likely off-road.
> >
> > 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).
> I manage to carry a 5-6 kg backpack biking from the nearby (4-5 km)
> shops. And the way back is uphill (not dramatic though). If it is
> reasonably flat in your area you will just need a backpack similar
> to mine - Lucy gave it to me when I got the bike, she had used it
> years ago when she was walking up the mountains. Very light but
> strong enough.
> >
> > But, recently, I'm liking the idea of a small gas powered generator
> > tucked in the battery compartment of my electric wheelchair (!).
> > This would eliminate the maintenance issue of the batteries
> > ($400/set) as well as increase the possible RELIABLE range of
> > the chair. (of course, you couldn't use it indoors but that's fine)
> >
> > Building on that idea, a gas powered Segway? <grin> >
> I have seen "normal" bicycles with a battery and some electric
> motor... I was told the motor just helps you, they are made not
> to move on their own, you have to pedal but you get assistance
> (making life easier uphill I suppose). Some nonsense that, why
> would I bike if I didn't want the exercise.
by global legislation
you can't turn your bike into scooter

Joerg wrote:
> On 6/14/22 10:16 AM, John Doe wrote:
>> 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. 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.
>>
>> This might be blasphemy, but...
>>
>> Speed and mileage indication is easily done with a smartphone these days,
>> at least here in America.
>>
>
> Then, later in the afternoon during an all-day ride, there will be a low
> battery warning, followed by a dark screen.
>
> Why do we always have to make things so complicated? When I grew up
> speedometers didn't even need any electrical power. They just worked.
>

And then pissed transmission oil on your pant cuffs when the oil seal
failed. ;)

Plus the nanny software didn't prevent one from putting the top down
while rolling, even turning round in the driveway. :(

I really wish there were a "nanny disable" button next to the one for
traction control.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On 6/15/2022 10:08 AM, Dimiter_Popoff wrote:
> On 6/15/2022 9:02, Don Y wrote:
>> ......
>>
>> I've been looking for an "alternate" form of transportation for the
>> little jaunts -- to the library, post office, etc. Just a couple of
>> miles, likely off-road.
>>
>> 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).
>
> I manage to carry a 5-6 kg backpack biking from the nearby (4-5 km)

Yeah, that would work. Often, I'm not carrying anything more than
something that needs to be mailed (at the post office) or returned
(to the library). So, getting my body mass from here to there is
the bigger issue.

[I'm not afraid of the exercise but the time required can be
annoying. E.g., at 4MPH, it takes me a little over an hour
to do the 4.5mi round trip to the library (using shortcuts
accessible to a pedestrian). OTOH, driving that same distance
takes almost half an hour as the route is slightly longer,
there are traffic signals to contend with, the car has to be
parked and locked up, etc. So, I "discount" the time spent
walking by the time it would take by car and figure I got
an extra half hour of exercise "for free" -- in terms of
time expended]

> shops. And the way back is uphill (not dramatic though).

The trip to the library is a long SLOW climb. My pace *going* is
a fair bit slower than returning (despite the fact that I'm more
tired on the return trip).

I've also noticed this within the neighborhood; traveling in
one direction requires more exertion than the other. The differences
in elevation aren't big but they take a toll on progress.

> If it is
> reasonably flat in your area you will just need a backpack similar
> to mine - Lucy gave it to me when I got the bike, she had used it
> years ago when she was walking up the mountains. Very light but
> strong enough.

My purchases are usually tied to a trip that had some other goal.
E.g., stopping in at the grocery store adjacent to the post
office for a few small items. Or, the hardware store on the
way BACK from the post office. Ditto at the library. I'd
not be inclined to buy anything heavy or bulky -- or *frozen*
(as it would *thaw* on the trip).

On a bicycle, I've carried the (one) bag in my hand while
also piloting the bike. It's not that difficult. But, avoiding
traffic is a challenge (pedestrian and cyclist "accidents" are
fairly common, here. Often fatal -- though rarely for the driver
of the CAR! :-/ )

>> But, recently, I'm liking the idea of a small gas powered generator
>> tucked in the battery compartment of my electric wheelchair (!).
>> This would eliminate the maintenance issue of the batteries
>> ($400/set) as well as increase the possible RELIABLE range of
>> the chair. (of course, you couldn't use it indoors but that's fine)
>>
>> Building on that idea, a gas powered Segway? <grin> >
>
> I have seen "normal" bicycles with a battery and some electric
> motor... I was told the motor just helps you, they are made not
> to move on their own, you have to pedal but you get assistance
> (making life easier uphill I suppose). Some nonsense that, why
> would I bike if I didn't want the exercise.

I think the motor will propel you but doesn't have enough torque to
get you moving from a dead stop (?). We also have a lot of gas-powered
bicycle assist units in use, here as a cheap form of transportation for
folks who don't want the cost/inconvenience of a car (e.g., students).
There is no licensing requirement nor requirement for insurance as
there is with a car.

But, they need to be driven on roadways. So, the marginally safer
use of sidewalks is out of the question. And, in many places, there
are no sidewalks so you're riding in the ~3 ft shoulder of the roadway.
(having cars pass within feet of you at 50 MPH is a disconcerting
feeling! "I wonder if the next guy has his eyes on the road -- or
on his phone???")

[Folks who ride recumbant bikes often have a tall "flag" attached
tot he bike frame to increase visibility. I'm not sure I'd rely on
that as a protective measure! :< ]

Clive Arthur wrote:
> On 14/06/2022 18:09, Dimiter_Popoff wrote:
>
> <snipped>
>>
>> Hmmm, but will that work at really low speed (like when pushing the
>> bike uphill)? It is an idea to do it this way (I did not even know the
>> name of the method so the idea is more than welcome), yet what I was
>> thinking was more in the line of changing some oscillation frequency
>> (thus detecting the spokes also  "at DC").
>
> A former colleague used a clever method for an impeller type flow
> sensor.  He used a small unshielded inductor with a parallel capacitor
> connected to a PIC pin.  Set the pin to be an output, kick the LC with a
> pulse, then set the pin to be an input and count oscillations.  In air,
> you get a few counts, near metal, you get fewer counts.  I don't know
> details, but he was able to sample sufficiently quickly for it to work.
>
> My guess is that it wouldn't be practical over the clearance distance
> you'd need for a spoke, but it's a neat method.
>

A digital theremin!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

Don Y <blockedofcourse@foo.invalid> wrote:
> On 6/15/2022 9:24 AM, Don wrote:
>> 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.
>
> GPS-based "distance traveled" figures tend to overestimate the
> actual distance traveled. Even a beginner is taught to always
> reference measurements from a common point (instead of stacking
> measurement errors).

FWIW, my bicycle is not electric. (Apparently some or all of those 15
cadence sensors cited by me earlier pertain to electric bicycles??) The
whole idea behind my spins is to get a good workout.

People sometimes ask me about my bicycle's fat tires. The tires are
fatter than those found on small motorcycles. They help me navigate
through light, dry snow. Fat tires are also ideal to yield three feet
over on the gravelly shoulder of the paved highway through the foothills
when a big pickup truck with extra wide mirrors screams past. If you
look closely at the left handlebar of my bike, you can spot a rear-view
mirror to keep me situationally aware of things going on behind my back.

My bike needs rear taillights and turn indicators more than a cadence
counter. The bike's NiteRider headlight battery ought to provide plenty
of juice as-is. But the rear lights will probably end up as DIY for lack
of any viable alternatives.

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 6/15/2022 11:04 AM, Don wrote:
> Don Y <blockedofcourse@foo.invalid> wrote:
>> On 6/15/2022 9:24 AM, Don wrote:
>>> 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.
>>
>> GPS-based "distance traveled" figures tend to overestimate the
>> actual distance traveled. Even a beginner is taught to always
>> reference measurements from a common point (instead of stacking
>> measurement errors).
>
> FWIW, my bicycle is not electric. (Apparently some or all of those 15
> cadence sensors cited by me earlier pertain to electric bicycles??) The
> whole idea behind my spins is to get a good workout.

I'm looking for options when I *don't* want a workout. There's a
difference between "going out for some chores" and "going out
for some execise". The former has a (immediate) purpose while the
latter's purpose is more long term.

> People sometimes ask me about my bicycle's fat tires. The tires are
> fatter than those found on small motorcycles. They help me navigate
> through light, dry snow. Fat tires are also ideal to yield three feet
> over on the gravelly shoulder of the paved highway through the foothills
> when a big pickup truck with extra wide mirrors screams past. If you
> look closely at the left handlebar of my bike, you can spot a rear-view
> mirror to keep me situationally aware of things going on behind my back.

Yes, my wheelchair's drive wheels are good enough for packed dirt
and firm lawns (and asphalt, concrete, etc.). But, tend to "spin"
in the decomposed granite that is common in place of lawns, here.

I'll mount more aggressive wheels if I take this approach:

<https://www.grizzlycentral.com/attachments/img_20161231_145627-jpg.42386/>

(Disabled) Folks who really go into this sort of thing can get
really aggressive in their solutions:

<https://i.pinimg.com/736x/b1/c4/b9/b1c4b9ede3aeeee5e134762c980db6d0.jpg>

<http://www.automotivenews.co.nz/wp-content/uploads/2014/08/10497961_526645007463753_6858744401557386684_o.jpg>

<https://bloximages.chicago2.vip.townnews.com/suncommercial.com/content/tncms/assets/v3/editorial/b/fb/bfbbc882-a630-11e3-ba40-0019bb2963f4/531a21b2150ce.image.jpg?resize=400%2C240>

But, they are truly looking for ATV-style solutions to ATV-style
problems. I'm just looking for a non-driving, non-walking way
to cover reasonably short distances (I'd never rely on walking
OR this sort of kludge if I wanted to travel a dozen miles)

> My bike needs rear taillights and turn indicators more than a cadence
> counter. The bike's NiteRider headlight battery ought to provide plenty
> of juice as-is. But the rear lights will probably end up as DIY for lack
> of any viable alternatives.

My wheelchair already has headlights, tail lights and turn signals.
And a horn! :-/

And (I think) a BT tie-in for "remote control". Battery isn't a problem
as there's ~100 pounds of them under the seat!

On 06/15/2022 09:33 AM, Don Y wrote:
>
> 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)

https://www.montaguebikes.com/product/paratrooper/

Any mountain bike will be at home off the pavement. I've got a Montague
because I wanted a full-sized folding bike I can put in the back of the
Yaris. Bike racks and hatchbacks don't play well together.

> 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.

I don't think sidewalk riding is illegal here but I wonder about the
people who ride on sidewalks or the shoulder of the road when there's a
perfectly good bike path six feet away.

Ebikes are up in the air. They're banned on quite a few trails but
there's no blanket prohibition. There's an attempt to distinguish
between electric assist and outright electric drive.

> 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.

Forty tears ago I'd ride on Boston streets. Over the years I gotten much
more paranoid. I gave up a favorite route because it's a narrow two lane
road with no shoulder. The fog line is the edge of the pavement and
there's only a ditch past it. Most people are good but it is frequented
by F350 dualies pulling stock trailers.

The other route is on a very wide shoulder for about three miles and
then a bike/pedestrian path.