Spoke sensor for bicycle

John Dope <always.look@message.header> wrote in news:t8b1a0$h8t$1
@dont-email.me:

> 
> Record-setting gas prices every day.

  You forgot to mention record setting profits for oil companies AND 
for the local gas stations, as they all jumped onto Trump's jack the 
price to make Biden look bad bandwagon.  You ain't fooling anyone, 
you retarded fucks.

> Highest inflation rate since 1981 when Ronald Reagan entered 
office.
 
  The fault also of the oil companies as the food prices, etc. all 
have logistical ties to fuel prices via the transportation industry 
that distributes the end products.

  You dopey Republitard idiots always conveniently ignore the factors 
driving inflation that besets a new administration, especially if the 
other party of previous admin is a bunch of vindictive idiots not 
caring about the nation as they take their jabs at the other party.

  Another reason why the likes of Perry should never hold a public 
office.

  You could not be more stupid if you tried.

Record-setting gas prices every day.

Highest inflation rate since 1981 when Ronald Reagan entered 
office.

The stock market is down to below when Joe Biden entered office.

Biden's approval rating is falling to new lows.



DecadentLinuxUserNumeroUno@decadence.org wrote:

> John Dope <always.look@message.header> wrote in news:t8b1a0$h8t$1
> @dont-email.me:
> 
>> 
>> Record-setting gas prices every day.
> 
>   You forgot to mention record setting profits for oil companies AND 
> for the local gas stations, as they all jumped onto Trump's jack the 
> price to make Biden look bad bandwagon.  You ain't fooling anyone, 
> you retarded fucks.
> 
>> Highest inflation rate since 1981 when Ronald Reagan entered 
> office.
>  
>   The fault also of the oil companies as the food prices, etc. all 
> have logistical ties to fuel prices via the transportation industry 
> that distributes the end products.
> 
>   You dopey Republitard idiots always conveniently ignore the factors 
> driving inflation that besets a new administration, especially if the 
> other party of previous admin is a bunch of vindictive idiots not 
> caring about the nation as they take their jabs at the other party.
> 
>   Another reason why the likes of Perry should never hold a public 
> office.
> 
>   You could not be more stupid if you tried.
> 

On 6/14/2022 1:39 PM, whit3rd wrote:
> On Tuesday, June 14, 2022 at 12:40:03 PM UTC-7, lang...@fonz.dk wrote:
>> tirsdag den 14. juni 2022 kl. 21.21.00 UTC+2 skrev Don Y:
> 
>>> Personally, if I saw some added value to rolling my own, I'd
>>> opt for a "vintage" speedometer's pickup:
>>>
>>> <https://i.ebayimg.com/images/g/JkMAAOSws21iGSc9/s-l1600.jpg>
>>>
>>> transferring motion through a "cable-in-cable" to a "head
>>> unit" that has been gutted. Mount a toothed gear on the end
>>> of the cable shaft *in* the head unit and sense rotation optically
>>> or variable reluctance. Quadrature detector if you want to
>>> be able to note direction of movement for FINE sensitivity.
>> how would that make any sense compared to the simple and ultra reliable reed and magnet?
>>
>> Rube Goldberg would be proud
> 
> Two advantages: it knows forward from reverse, and it has angular sensitivity to sub-one-revolution
> movement.    It also doesn't need an adjustment-type mount for the sensor, just
> slap it around the axle and mount the wheel.   There's nothing to prevent that kind
> of axle-mount item from having a magnet and quadrature reed switches, of course; the speedometer-cable
> is a bit of a hassle compared to a signal wire.
> 
> A better solution would be to instument a hub and axle, but the axle diameter is fixed by the bicycle frame, and
> the hub by the wheel-builders.   That means redesigns of the mechanical bits unless one lucks out and
> finds a compatible generator hub off-the-shelf.

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...)

On Tuesday, June 14, 2022 at 5:22:18 PM UTC-7, Don Y wrote:
> On 6/14/2022 1:39 PM, whit3rd wrote: 

> > A better solution would be to instument a hub and axle, but the axle diameter is fixed by the bicycle frame, and 
> > the hub by the wheel-builders. That means redesigns of the mechanical bits unless one lucks out and 
> > finds a compatible generator hub off-the-shelf.

> 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...)

Yeah; those delivered 2 or 3 watts; enough for a halogen flashlight lamp,
and to charge a 6V lead/acid battery for standstill lighting.   If you use
one built into a wheel hub, the dynamo pole count determines the AC cycles per mile travelled.
The friction type can be precalibrated easily (the drive drum circumference is better known
than the tire's) if  it engages the tread  rather than the sidewall of the tire.

On 06/14/2022 12:00 PM, Dimiter_Popoff wrote:
> On 6/14/2022 20:43, Jan Panteltje wrote:
>> On a sunny day (Tue, 14 Jun 2022 18:51:21 +0300) it happened
>> Dimiter_Popoff
>> <dp@tgi-sci.com> wrote in <t8aapr$ab6$1@dont-email.me>:
>>
>>> 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.
>>
>> Or you could make something like my gm_pic2:
>>   http://panteltje.com/panteltje/pic/gm_pic2/
>>
>> It uses GPS and writes to SDcard or EEPROM where you were at any time,
>> logs radiation there too
>> There is software to replay the trip on google maps.
>> After all the GPS talk here ..
>> Simple maaz using the space and time between data points will allow
>> you to find speed and distances.
>> A GPS module and a Microchip 18F14k22 + EEPROM is all you need.
>> Oh and a battery...
>> Now been working 24/7 for 8 years... As clock mostly.
>> No tinkering with your bike needed.
>> Also logs trips per bus or train.
>>
>>
>
> Is the GPS accuracy/latency of the speed measurement close to that of
> a car's speed indicator?


Most of the time. The 14" studded tires I run in the winter have a 
smaller rolling diameter than the 15" tires the speedometer is 
calibrated for so it's off by about 5mph. For that reason I'm in the 
habit of looking at the Nuvi speed rather than the speedometer.

In some weather conditions or when I'm driving at the base of a ridge 
that blocks the southern sky the GPS is wildly inaccurate so much so it 
is easy to detect when it's having issues.

I often carry a GPSr when I'm hiking (Garmin Etex 20). The terrain is 
mountainous here so satellite coverage can be sketchy. Sometimes the 
distance is radically off as is the maximum speed. Unless I just rolled 
down a slope I'm probably not hitting 4.7 mph. I don't think the device 
has the intelligence to discard obvious false data points.

I've got one of the step apps on the phone. It says it does not use the 
GPS so it's working off the accelerometer data and it's surprisingly 
accurate for the mileage particularly considering there was no setup for 
the length of my stride.

On 06/14/2022 12:44 PM, Lasse Langwadt Christensen wrote:
> tirsdag den 14. juni 2022 kl. 20.00.52 UTC+2 skrev Dimiter Popoff:
>> On 6/14/2022 20:43, Jan Panteltje wrote:
>>> On a sunny day (Tue, 14 Jun 2022 18:51:21 +0300) it happened Dimiter_Popoff
>>> <d...@tgi-sci.com> wrote in <t8aapr$ab6$1...@dont-email.me>:
>>>
>>>> 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.
>>>
>>> Or you could make something like my gm_pic2:
>>> http://panteltje.com/panteltje/pic/gm_pic2/
>>>
>>> It uses GPS and writes to SDcard or EEPROM where you were at any time, logs radiation there too
>>> There is software to replay the trip on google maps.
>>> After all the GPS talk here ..
>>> Simple maaz using the space and time between data points will allow you to find speed and distances.
>>> A GPS module and a Microchip 18F14k22 + EEPROM is all you need.
>>> Oh and a battery...
>>> Now been working 24/7 for 8 years... As clock mostly.
>>> No tinkering with your bike needed.
>>> Also logs trips per bus or train.
>>>
>>>
>> Is the GPS accuracy/latency of the speed measurement close to that of
>> a car's speed indicator?
>
> a car speedometer is only required to be -0 to +10%
>

And for most Japanese motorcycles it is +10%. The conventional wisdom is 
it's a liability thing. Since they can't control aftermarket tires they 
overstate the speed. You get used to subtracting 5 mph from the reading.

On 06/14/2022 01:01 PM, Dimiter_Popoff wrote:
> On 6/14/2022 21:21, whit3rd wrote:
>> On Tuesday, June 14, 2022 at 8:51:30 AM UTC-7, 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.
>>> ...use a magnet placed somewhere on one
>>> of the wheels and some sensor, ... I
>>> imagine it sensing just the spokes, i.e. making some inductive sensor.
>>
>> A magnet secured to a spoke, and a reed switch,  makes a durable
>> sensor, but
>> is somewhat clumsy.   A sensor of the metal spoke is hard, because spokes
>> aren't all magnetic, there's stainless steels.
>
> Aaaah, the stainless steel is a game changer of course. Had not thought
> of that at all - though I know the spokes are not rusty (some at the end
> where they are tightened to the wheel but not all and not much). And it
> is not like they have not seen water, 1-2 months ago getting back
> after waiting for a torrential rain to subside I was nearly in submarine
> mode ...


Carbon fiber spokes would be a problem too. The LCD odometer on my 
motorcycle is old and is only legible if the temperature is close to 90 
F so I adapted a bike speedometer/odometer. I epoxied the magnet on the 
rim near the tire bead and built a bracket for the sensor. It works 
quite well and since I can program in the rolling diameter of the front 
wheel it is very accurate.

On 06/14/2022 12:24 PM, 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.
>

They just worked until the core of the flexible shaft broke. If you were 
lucky the strands didn't tear up the housing so you could buy a new 
core, figure out how long it had to be, cut if off, and crimp on the 
square drive end. If you were really lucky the transmission end of the 
drive was above the lubricant level so you didn't have Type F fluid 
running down your arm.

While I can get nostalgic for the good old days I'm not senile enough to 
forget what a pain in the butt it was when things just didn't work.

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

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.

On Tuesday, June 14, 2022 at 2:36:47 PM UTC-4, lang...@fonz.dk wrote:
> tirsdag den 14. juni 2022 kl. 20.28.02 UTC+2 skrev Ricky: 
> > On Tuesday, June 14, 2022 at 2:00:52 PM UTC-4, Dimiter Popoff wrote: 
> > > On 6/14/2022 20:43, Jan Panteltje wrote: 
> > > > On a sunny day (Tue, 14 Jun 2022 18:51:21 +0300) it happened Dimiter_Popoff 
> > > > <d...@tgi-sci.com> wrote in <t8aapr$ab6$1...@dont-email.me>: 
> > > > 
> > > >> 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. 
> > > > 
> > > > Or you could make something like my gm_pic2: 
> > > > http://panteltje.com/panteltje/pic/gm_pic2/ 
> > > > 
> > > > It uses GPS and writes to SDcard or EEPROM where you were at any time, logs radiation there too 
> > > > There is software to replay the trip on google maps. 
> > > > After all the GPS talk here .. 
> > > > Simple maaz using the space and time between data points will allow you to find speed and distances. 
> > > > A GPS module and a Microchip 18F14k22 + EEPROM is all you need. 
> > > > Oh and a battery... 
> > > > Now been working 24/7 for 8 years... As clock mostly. 
> > > > No tinkering with your bike needed. 
> > > > Also logs trips per bus or train. 
> > > > 
> > > > 
> > > Is the GPS accuracy/latency of the speed measurement close to that of 
> > > a car's speed indicator? 
> > "Close" is probably the best you can claim. Each 1 second update is a second old by the time you get it from the GPS. The accuracy can be there, but it depends on the constellation. With some xx feet of accuracy, each calculation can have errors that are significant if you are not moving fast. 30 mph is 44 fps, so 14 foot accuracy (what I'm seeing now and a typical value) is significant. GPS measurements are typically filtered. That's one reason why your car navigation can prompt you rather late sometimes (or early). It is hard for a GPS to know what lane you are in, but can tell if you are on the parallel access road and not the main highway. 
> >
> https://www.gps.gov/systems/gps/performance/accuracy/

"This measure must be combined with other factors outside the government's control, including satellite geometry, signal blockage, atmospheric conditions, and receiver design features/quality, to calculate a particular receiver's speed accuracy."

-- 

Rick C.

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