Do any cadence sensored hub motor controllers activate pedal assist when ghost pedalling backwards as well as forwards?

[guerney]

You could adapt many by sticking reverse polarity magnets beween the normal ones, then you'd get the correct signal whichever way you pedalled unless you had a dual hall sensor. Alternatively, in a 10 magnet disc, you could try pressing out and reversing every other magnet so that you have alternating N and S.

Thank you. Unless some intrepid soul on this forum tries this first, I will, if I ever convert using a hub motor kit. Can you recall which controllers? Were they current controlled or the crappier speed controlled?

There was a specific requirement under the 2009 EN15194 standard which I assume probably still applies that pedaling backwards will not activate the motor as below.

View attachment 60175

Thanks for answering my question. When stopped by the rozzers, simply switch off the PAS senor? Could claim the bike had broken down shortly before - who knows, you might be believed if you weren't bombing down the road? Or switch to the second PAS disc on the opposite side, which has magnets oriented for forward pedal assist? Or fashion some mechanism which can swiftly click one set of magnets too far away and bring the other set closer, or flip the required magnets over with a sneaky kick of a heel? If caught somehow, surely backpedalling pedal assist is less illegal than an independently operating throttle faster than 6kph? Can they throw the book at you for operating a motorbike without insurance etc, if all you have is a backpedal activated EAPC? Would it be more of a pamphlet? A pamphlet wouldn't hurt as much.

When the motor activates by pedalling backwards, it's a bit dodgy because you have to lift the pedal to get ready to ride. That's going to be a bit awkward when the bike surges forward each time you attempt to move the pedals. It would require a bit more sophistication in the control system to make sure that it didn't go when you didn't want it to. Also, pedalling backwards to start up a hill is going to be a nightmare.

Might not be too bad? Start with ebrake+brakes on, pedal backwards to activate the motor, having let go of brakes a split second before... then continue pedalling backwards temporarily, until you're travelling forward fast enough to easily pedal forwards? Could end up rolling downhill of course once the ebrakes are let go, if there's a huge preset pause between ebrake and the start of pedal assist.

If the cadence sensor has just the three wires, then my guess is that there are two Hall effect sensors, which produce a quadrature signal as the pedals turn, and there is a little bit of internal logic which gates one of the quadrature waveforms with the derived direction signal, so there's no pulse train output when pedalling in reverse.

Replacing the internal logic is something I hope to avoid.

 

[saneagle]

Thank you. Unless some intrepid soul on this forum tries this first, I will, if I ever convert using a hub motor kit. Can you recall which controllers? Were they current controlled or the crappier speed controlled?




Thanks for answering my question. When stopped by the rozzers, simply switch off the PAS senor? Could claim the bike had broken down shortly before - who knows, you might be believed if you weren't bombing down the road? Or switch to the second PAS disc on the opposite side, which has magnets oriented for forward pedal assist? Or fashion some mechanism which can swiftly click one set of magnets too far away and bring the other set closer, or flip the required magnets over with a sneaky kick of a heel? If caught somehow, surely backpedalling pedal assist is less illegal than an independently operating throttle faster than 6kph? Can they throw the book at you for operating a motorbike without insurance etc, if all you have is a backpedal activated EAPC? Would it be more of a pamphlet? A pamphlet wouldn't hurt as much.




Might not be too bad? Start with ebrake+brakes on, pedal backwards to activate the motor, having let go of brakes a split second before... then continue pedalling backwards temporarily, until you're travelling forward fast enough to easily pedal forwards? Could end up rolling downhill of course once the ebrakes are let go, if there's a huge preset pause between ebrake and the start of pedal assist.




Replacing the internal logic is something I hope to avoid.

All I know is that a couple of months or so agao there was a guy on this forum that mentioned that his PAS worked forwards and backwards. The problem he wanted solved was something else, so nobody paid any attention to it. I just made a mental note of it at the time because it's unusual.

This isn't it, but it's the same. See post #26 onwards.

Alternatives to flipping PAS disc?

It only works on the cheapo single hall type. Those type of sensors work simply and reliably. I can't understand what the advantage in dual sensors is. They only bring compatibility problems I don't understand how a single-hall sensor can tell the difference between the two directions. Do you...

www.pedelecs.co.uk

 

[thelarkbox]

Perhaps? with a small dc motor and a cheap all in one pas sensor, you could rig up a push button to turn the motor to rotate the pas sensor, box it up somewhere and hide it on the bike, route the button to the handle bars and the pas signal wire and ground to the pas sensor input of your controller and press the button when needed.

 

[eas2lv]

Perhaps? with a small dc motor and a cheap all in one pas sensor, you could rig up a push button to turn the motor to rotate the pas sensor, box it up somewhere and hide it on the bike, route the button to the handle bars and the pas signal wire and ground to the pas sensor input of your controller and press the button when needed.

If back pedalling is not a requirement, just use a 555 Timer IC to generate a pulse train. About 10Hz with 1:2 ratio for on/off would work perfectly. Pretty easy and cheap.

 

[Peter.Bridge]

Slightly off topic but I have noticed the power output on the display varies with cadence, am I imagining that ?

 

[saneagle]

Perhaps? with a small dc motor and a cheap all in one pas sensor, you could rig up a push button to turn the motor to rotate the pas sensor, box it up somewhere and hide it on the bike, route the button to the handle bars and the pas signal wire and ground to the pas sensor input of your controller and press the button when needed.

You don't need to do that. You can buy signal generator modules on Ebay for about £3 that conveniently run off 5v, so have the same three wires as a pedal sensor. You can put a switch on the 5v wire, then either plug it in to the pedal sensor connector or splice it into the pedal sensor wires. When you press the button, it'll make the PAS signal as if you're pedalling.

NE555 Adjustable Module Duty Cycle Pulse Frequency Square Wave Signal Generator | eBay

Main chip: NE555. 1X NE555 Duty Cycle Adjustable Pulse Frequency Square Wave Signal Generator Module. An indicator LED illuminates on a low-level output and flashes relative to the output frequency. At higher frequencies, the LED will appear to be on solid and without a visible flash.

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This one is easier:

Signal Generator PWM Pulse Frequency Duty Cycle Adjustable Module Square Wave | eBay

LCD display frequency and duty cycle, clear at a glance, PWM output can set frequency and duty cycle;. PWM output, frequency and duty cycle can be set;. XXX(no decimal point): the minimum unit is 1Hz, and the value range is 1Hz～999Hz;.

www.ebay.co.uk

 

[thelarkbox]

Slightly off topic but I have noticed the power output on the display varies with cadence, am I imagining that ?

Is one of us having a 'blonde moment', seems like more effort you put in (higher cadence same gear) the less the motor needs to provide to maintain the same output??

You don't need to do that. You can buy signal generator modules on Ebay for about £3 that conveniently run off 5v, so have the same three wires as a pedal sensor. You can put a switch on the 5v wire, then either plug it in to the pedal sensor connector or splice it into the pedal sensor wires. When you press the button, it'll make the PAS signal as if you're pedalling.

NE555 Adjustable Module Duty Cycle Pulse Frequency Square Wave Signal Generator | eBay

Main chip: NE555. 1X NE555 Duty Cycle Adjustable Pulse Frequency Square Wave Signal Generator Module. An indicator LED illuminates on a low-level output and flashes relative to the output frequency. At higher frequencies, the LED will appear to be on solid and without a visible flash.

www.ebay.co.uk

This one is easier:

Signal Generator PWM Pulse Frequency Duty Cycle Adjustable Module Square Wave | eBay

LCD display frequency and duty cycle, clear at a glance, PWM output can set frequency and duty cycle;. PWM output, frequency and duty cycle can be set;. XXX(no decimal point): the minimum unit is 1Hz, and the value range is 1Hz～999Hz;.

www.ebay.co.uk

- Doh! - yeah it was late last night - great time for overlooking whats right in front of you.. cheers..

 

[saneagle]

Slightly off topic but I have noticed the power output on the display varies with cadence, am I imagining that ?

The power varies with motor speed. The faster it spins, the less current it can take. In other words the power is regulated by the motor speed independently of the controller. Whichever of the two allows the lower power, that's what you get. At low speed, the controller normally wins, and the motor wins at high speed.

 

[guerney]

All I know is that a couple of months or so agao there was a guy on this forum that mentioned that his PAS worked forwards and backwards. The problem he wanted solved was something else, so nobody paid any attention to it. I just made a mental note of it at the time because it's unusual.

This isn't it, but it's the same. See post #26 onwards.

Alternatives to flipping PAS disc?

It only works on the cheapo single hall type. Those type of sensors work simply and reliably. I can't understand what the advantage in dual sensors is. They only bring compatibility problems I don't understand how a single-hall sensor can tell the difference between the two directions. Do you...

www.pedelecs.co.uk

I won't be trying this, because it doesn't appear to be legal and I don't want the grief- according to this post, that OP had a Lishui speed controlled controller supplied with a Yosepower kit, of which there are many owned by forum members.

https://www.pedelecs.co.uk/forum/threads/alternatives-to-flipping-pas-disc.40349/post-602478


In the highly unlikely event a Yosepower kit owning forumite with the same Lishui controller fancies experimenting and investigating further, this product matches the blurb:

https://www.amazon.co.uk/VGEBY-Magnets-Assistant-Electric-Mountain/dp/B07NKGM8W2

 

[afzal]

Luna cycle's BBSHD that runs VESC has 2-wire quadrature PAS (https://ebikes.ca/learn/pedal-assist.html#SignalLevels), which helps the VESC in figuring out the direction.

If a start up assist (toggle) switch is added, VESC firmware may be modified to check the status of the switch & upon detecting reverse pedalling, provide assist till 6pkh (& toggle the switch state in firmware). Here it might be reasoned that this doesn't go against EN15194 since backwards pedalling per se won't provide any assist (also pass the EN15194 backwards pedalling test procedure), rather it is part of start up assist mode setting, further it would cut-off at 6kph. But then one might very well subtract reverse pedalling from the equation & instead use only start up assist switch

Oh yes, BBSHD in itself in illegal in UK (they have a legal US version), all I am saying is the possibility of tinkering the VESC & using it on another legal setup with a 2-wire PAS.

I have a 1-wire PAS sensor that provides signal in forward & reverse direction, it was really difficult to use the bike in a safe manner & it was abandoned. It was not varying the pulse width depending on the direction (see Grin's link above for Varied Width PAS 1-wire), so there was no straight forward way to figure out the direction.

EDIT: EN15194 mentions no assist when pedalling backwards & nothing specific to start up assist, modify above accordingly.

 

[guerney]

Luna cycle's BBSHD that runs VESC has 2-wire quadrature PAS (https://ebikes.ca/learn/pedal-assist.html#SignalLevels), which helps the VESC in figuring out the direction.

If a start up assist (toggle) switch is added, VESC firmware may be modified to check the status of the switch & upon detecting reverse pedalling, provide assist till 6pkh (& toggle the switch state in firmware). Here it might be reasoned that this doesn't go against EN15194 since backwards pedalling per se won't provide start assist, rather it is part of start up assist mode setting, further it would cut-off at 6kph. But then one might very well subtract reverse pedalling from the equation & instead use only start up assist switch

I wondered how long it'd be before VESC was mentioned. All sorts of stuff should be possible with code. I like the sneaky legality reasoning - to make distinction clear, if say perhaps when starting uphill from a dead stop, a non-latching button on the handlebar (which is enabled when the bike is standing still) could be pressed and released before pedalling backwards, which temporarily disables the ebrakes, and after a small amount of backpedalling has been detected, a 6kph start-up assist could be made available for the second pressing of the same switch, within a few seconds after the first press? Re-enable ebrakes upon start of backpedal activated start assist. Pedal forwards pedal assist would remain as normal, as an option. In a back wheel off the ground test by cops, a press of that switch would have no effect. "That's no thottle, it's a start-up assist orifcer, activated by backpedalling which doesn't activate pedal assistance. Remove these handcuffs immediately! I'm allergic to nickel! Arrrggghhh! It burns! Don't you know nickel causes cancer? It's on our coins. Why is carcinogenic nickel on handcuffs and coins?" etc.

 

[afzal]

Edited the previous post to be more inline with EN15194

All sorts of stuff should be possible with code.

Yes, it is due to the necessity of being compliant with EN15194, otherwise there are ways to achieve w/o modifying internal logic

 

[Woosh]

...I'm wondering if any cadence sensored hub motor controllers are capable of activating pedal assist when ghost pedalling backwards as well as forwards, because it strikes me this would be an advatage for hill starts - one reason why many are keen on throttles.

You can do that but it's extremely dangerous. Let's say you are at the traffic lights and the lights are red. If you move accidentally your cranks backward, you can cause an accident.
This said, there are two ways that the controllers can be programmed: for single Hall or for dual Hall. Single Hall has no intelligence, will deliver the signal when the cranks move backward or forward. Dual Hall only delivers the signal when you pedal forward, even when you flip the magnet disc.
To achieve what you want to do, buy a controller for dual Hall and fit a single Hall sensor. I repeat again, not to be recommended.

 

[saneagle]

Single Hall has no intelligence, will deliver the signal when the cranks move backward or forward. Dual Hall only delivers the signal when you pedal forward, even when you flip the magnet disc.

I don't think you've worded that very well. Single hall sensors only work in one direction. You can get them to work in the reverse direction by swapping the orientation of the magnets in the N-S axis, i.e. flip the magnet disc.

A dual sensor one can also be reversed by flipping both the magnet disc and rotating the sensor 180deg to reverse the direction the magnets move over it.

To summarise, there are 4 combinations of direction and magnet orientation. A single hall works in one direction with two of the combinations, and a double hall works with one combination.

 

[Woosh]

Next time you come to Southend, I will show you how clever the king meter DH pedal sensor (all black) is when used with a controller programmed for it. You can't start the motor by pedalling backward whichever way you fit the sensor and the magnet disc. If you plug in the same controller a single hall (red) sensor, you can make the motor start when pedalling backward by flipping the disc. All my hub kits use km dh sensors. Finger troubles proof.

 

[saneagle]

Next time you come to Southend, I will show you how clever the king meter DH pedal sensor (all black) is when used with a controller programmed for it. You can't start the motor by pedalling backward whichever way you fit the sensor and the magnet disc. If you plug in the same controller a single hall (red) sensor, you can make the motor start when pedalling backward by flipping the disc. All my hub kits use km dh sensors. Finger troubles proof.

All we want is that when we start to pedal, the motor starts up quickly and efficiently, and it stops quickly when we stop pedalling. We don't need anything clever for that. Fitting a dual hall sensor with a fancy controller is akin to using a £7,000 carbon fibre full suspension 12 speed MTB ebike to ride one mile to the shops and back to get your milk and paper. It works, but a £340 Argos ebike does it just as well with much less risk.

 

[guerney]

If pedal assist started fast enough, there wouldn't be countless threads about throttles and their legality on this forum. If backpdalling made available start assist up to 6kph as described in post #31, as far as I can tell, it'd be legal - it needn't be a non-latching button, it could be a throttle for finer control, limited to 6kph, which is inactive until you press it down, and backpedal within a few seconds of release. Inactive when pressed by cops. My BBS01B is set to start pedal assist fast, I don't need start assist, but clearly many do. There wouldn't be demand for bikes with DVSA approved throttles, if pedal assist started fast enough for those throttle loving dudes.

 

[Nealh]

Thumb start modes seem to be needed because ;
1.Fit riders are lazy and don't want to pedal .
2. Unfit riders wanting to ride , still thinking they are as good as they were as if they were in their earlier years.
3. Ligitimate cases where some type of disability means a rider has little stamina or strength but still wish to be active.
4. Some have balance /bike control issues and really should be riding a trike type bike or shouldn't be riding as they are clear dange rto themselves, let alone others.
5. The bikes they ride just have crappy controller with poor PAS logarithm's .
6. Some riders simply buy the wrong drive system for their needs such as TS control bike , in which case the first four will easily apply .

It is quite obvious that at least two controller types have fast PAS start and stop with little lag on start up or overide when stopping.

Woosh promote there Lishui /KM set up as being one and the likes of d8veh and I highy regard the KT set up.
I for one can vouch that the KT start up is less then 1/8th pedal rotation which will be more then adequate for every one, it is much much quicker and will get one going faster then an ordinary unpowered bike.
The stop is instant no overun or need for brake cut offs.

Some will disagree with some of the above but I speak as I see it and read posts on the forum over the years , some folks may read and feel offended s but that is free speech for you and speak as I see it .

Not wanting to set out to offend or discriminate against any particular person or group , one has to be honest and put things in to honest perspective of ones actual ability and whether they are or will be putting themselves in harms way.

 

[guerney]

2. Unfit riders wanting to ride , still thinking they are a sgood as they were as if they were in their earlier years.
3. Ligitimate cases where some type of disability means a rider has little stamina or strength but still wish to be active.
4. The bikes they ride just have crappy controller with poor PAS logarithm's .

Clearly, all that must be common, because it powers fingers to pound keyboards creating and populating countless threads about throttles, and sales of bikes with DVSA approved throttles. I reckon a backpedal enabled start assist throttle option as described above, has money making legs for someone. I don't have a horse in this race, but others do.

 

[saneagle]

If pedal assist started fast enough, there wouldn't be countless threads about throttles and their legality on this forum.

Torque sensors start the motor very quickly, but you still can't start up a steep hill. Pedalling backwards, likewise won't help. The only reason throttles help is because you can keep your legs down to balance while the bike gathers speed enough to let the gyroscopic effect of the wheels to take effect.

The easiest way to do a throttle-type start up with a bike that only has cadence sensor pedal assist is to spoof the signal with one of these, as I've said many times before. All you need is a switch on the 5v wire to activate it. I have one and tested it. It works. It can also be used to spoof the speed signal.

XY-LPWM Signal Generator PWM Board Module Pulse Frequency Duty Cycle Adjustable | eBay

Clear LCD Display: This module has an easy-to-read LCD screen that displays the frequency and duty cycle of the PWM output signal, making it easy to monitor and adjust your settings. PWM output, frequency and duty cycle can be set;.

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