Add thumb throttle to Hoptown 500: possible? how?

[Sacker]

Hello and thank you in advance for your attention and help,

short version: I want to add a thumb throttle / throttle button to my Decathlon Hoptown 500 ebike. How can I do it?

long version: In the Hoptown 500 the motor is enabled by pedaling. The only controls available are:

With Eco the bike goes until 15 km/h, Normal 20 km/h, Sport +25 km/h. Motor response is always the same, so the activation seems to be on/off. I would like to have a button to trigger that on/off besides the pedal movement (or a thumb throttle or lever if it really isn't a on/off thing).

I unmounted the bike and saw this:

I don't see any connector for a throttle. I asked Google about the controller to know what does what in that PCB with no luck. But, I found similar models, like:

https://es.aliexpress.com/item/33015002130.html?spm=a2g0o.productlist.0.0.110c7deePCK0gI&s=p&algo_pvid=2d0a9edc-660c-4b67-8530-682be1fd12e7&algo_expid=2d0a9edc-660c-4b67-8530-682be1fd12e7-11&btsid=99343e08-071b-4dae-a110-0d5850505fa6&ws_ab_test=searchweb0_0,searchweb201602_1,searchweb201603_53

It says 9pin throttle-brake-display light. So maybe my bike has the throttle cables there in the controller but no throttle is connected? Maybe I can connect something like this properly re-wiring? I don't mind if I loose the 3 speed switch (as long as I can wire something to be always in "Sport" mode/full speed available mode).

Or in these models only activation by PAS sensor is available?

Thank you again and sorry for the photo quality, I can take better/more specific ones if needed

 

[Voltron]

Sometimes you can change to a same brand but better display, that adds a throttle plug. But depending on how much time you want to spend searching instead of riding, maybe just get a new controller/display/throttle that matches the motor plugs, and just save your existing unit as a backup.
For that generic, mid power level setup, it's usually the cheapest part to upgrade.

 

[docw009]

The label on the controller says it has a throttle capability, but there is no connector for it. You would have to identify the unused pads on the circuit board. You need ground, +5V and the throttle input. Finding the throttle pad is something that could be done by trial and error, probing random pads, but it's very easy to blow something up unless you're an experienced with electrical matters,

You could use the same ground and +5 used by the PAS sensor,

To make it simple, use a three wire throttle.
https://es.aliexpress.com/item/33046368806.html?spm=a2g0o.productlist.0.0.39506a544bPXHr&algo_pvid=dce68562-5bc9-447d-b909-ec146cd30bb9&algo_expid=dce68562-5bc9-447d-b909-ec146cd30bb9-6&btsid=fa97da74-9602-419e-900f-079d359601dd&ws_ab_test=searchweb0_0,searchweb201602_5,searchweb201603_53

 

[Sacker]

Finding the throttle pad is something that could be done by trial and error, probing random pads, but it's very easy to blow something up unless you're an experienced with electrical matters

Yep, trial and error sounds very dangerous in my head : S

just get a new controller/display/throttle that matches the motor plugs, and just save your existing unit as a backup.

You're right Voltron, that's probably the best money/time/risk combination in this case

But I don't think the throttle is worth ~50/60€. I guess I'll live without it until that controller goes away and then invest in a new controller/display/throttle combo as you say.

Thank you Voltron, docw009 very much!

 

[amberwolf]

almsot always the throttle input pad is marked as

sp

so a hall based throttle is wired with it's signal output wire (usually white or green) to that pad, and it's power wire (usually red) to any 5v pad, even sharing one with another wire is ok. then it's ground wire (usually black) goes to any ground pad.

almsot always the sp pad is along the same edge as other inputs, typicaly in the area that on yours is in the far right lower corner in the pic you've posted. most likely it's under the white ziptied cable bundle.

pads are usually marked on both sides of the pcb, so you shouldn't have to move the cable to find it.

it's possible it may be somewhere else on the board, like over in the mddle near the sl pad.

 

[Sacker]

oh thank you amberwolf!! I'll search for that sp pad. If it's there that will reduce a lot the "trial and error" search for the throttle

One more question, if I find the pad, to test if it works without buy a throttle, I can just take the positive of a 1,2 - 4,2V source and plug in there? I imagine that what the throttle does is put a voltage in that range depending on the "gas" demanded in the signal cable, but it's just an imaginative assumption for now

 

[TommyCat]

My favorite...

For this and other testing options, and what to look out for, see... THIS POST.

Note: the ground or negative side of the button battery must be used.

To see relations between throttle voltage output and motor response, scroll up a bit. :wink:


Regards,
T.C.

 

[Sacker]

Tommycat just... WOW! what a post! Saved like gold in my computer right now : D

thank you very much

 

[Sacker]

it's possible it may be somewhere else on the board, like over in the mddle near the sl pad.

SP was one pad away the SL pad!! And it IS the throttle, hats off to you amberwolf!!!

To check that the pad was the throttle and that it works in my controller, I took the advice of TommyCat and made a "nearly 3V" external battery :

And yeah, it worked!!! Now I just have to order a three wire throttle and not screw up everything soldering the thing. Fingers crossed

Thank you very very very much guys, you're awesome

 

[TommyCat]

What a fantastic way to start the NEW YEAR! Way to get after it!

Note: your controller specifies the use of a hall sensor type throttle, not potentiometer type. (both have 3 wires)

Glad to have helped.

 

[giulio400]

dear sacker I have the same bike and I'd like to put a button to activate the engine, a simple on / off.
I didn't understand what are the pins of sl and sp.
May you help and tell me what is the easiest way to do it?
Thanks in advance!

 

[amberwolf]

I'd like to put a button to activate the engine, a simple on / off.

so you want it to only be able to just suddenly have full power, from no power at all?

that's could be hard on the mechanical parts, as well as the battery.

if it's not full power that you're after then you will want something adjustable between the button and the controller.


either way, if that's what you want to do, then you would put a potentiometer in or near the controller, so taht you can set the level of power you're after with the button, and adjust it experimentally until it does wha tyou want.

the middle wire from the pot goes to one side of the "activation button".

the other side of the "activation button" goes to the sp pad in the controller.

one end wire from the pot goes to any 5v pad in the controller.

the other end wire from the pot goes to any ground gnd pad in the controller.

flip the bike upside down and turn it on.

turn the pot's knob to the middle of ti's range.

press and hold the activation button, and turn the pots knob until the wheel goes as fast as it can, just before it stops spinning.

now it is set for full power output whenever you press that button.


if yo udon't want full power ewhenver you press the button, turn the pots knob until it is at the power you want it to be.

 

[Sacker]

What a fantastic way to start the NEW YEAR! Way to get after it!

Note: your controller specifies the use of a hall sensor type throttle, not potentiometer type. (both have 3 wires)

Glad to have helped.

Thank you TommyCat! I'll look carefully for the throttle type, but I'm seeing that it is not specified in a lot of models : (

dear sacker I have the same bike and I'd like to put a button to activate the engine, a simple on / off.

Hi giulio! As amberwolf explain perfectly, the on / off option is not the best option for your bike (and not for you as well, 0 to full power will not be the most smooth riding experience). Plus, you will probably want to use the accelerator as a "walk" feature in some situations, like a complicated climb, where you want to walk with the bike on your side but not push all it's weight.

I'm still looking for a throttle, if I succeed I'll share the details with you (and the community :> )

 

[E-HP]

Hi giulio! As amberwolf explain perfectly, the on / off option is not the best option for your bike (and not for you as well, 0 to full power will not be the most smooth riding experience).

This is totally subjective and depends on the bike and riding style. If your primary mode is to use pedal assist, and only want the boost in certain situations, the button works great. Especially since you're running such low power. I used a similar button on my bike for a few months it worked great with how I ride, and since I only really use throttle when I need full power anyway. Using my button, I'd get an instant boost to 1000W-1500W or more, depending on the terrain when I'd press it, and it worked great. Think of it as akin to the nitrous (fun) button on a hot rod. I wouldn't use it on a bike running 72V, but on anything 52V and below, it's a nice option for some riders.

 

[Sacker]

Think of it as akin to the nitrous (fun) button on a hot rod.

With this use, sure! I thought in a use including "start from a stop" because of giulio's words ("I'd like to put a button to activate the engine"). Even starting from 0 with our 24V setup maybe the full power is not that much and you could use it like that but... having the option of install a throttle, I think is better to have the choice of go full power or any other power level : )

 

[amberwolf]

fwiw, there are definitely systems and situations where a simple "go" button of full power works fine.

my really heavy sb cruiser trike takes a crapload of power to get it started, and i can't relaly do it anymore by just pedalling without relaly low gears to start and then gearshifting up quckly. i have the syste setup for pas control of system, but thru the cycle analyst it requires 50rpm detection before it will even begin applying any power (even with torque pas).

so since in some situations i can't get that rpm at all before pain in knees/etc, i have to use a throttle at full power for jsut a second or so to get going enough that i can then control it all with just the pedals.

i only have hte throttels on there at all becaus there are rare times i can't pedal at all, so i have to use some other method to control power/speed, and throttle is easy enough. but i use pedal pas most of the time becaus my hands go numb randomkly, and a hand/finger throttle of any kind is hard to use when that happens. and also hve them on there because sometimes stuff breaks, and if pas fails to work i have to use throttle, as i can't practically ride the trike without power at all.

a button would work great in this case, just applying full throttel to the system. iv'e even considered putting a wireless on/off on the pedal surface itself that would take a lot of pressure to activate, so it only happens hwen i am starting from a stop, but tha'ts too complicated.

iv'e also considered using an external amplifier on the torque sensor output, instead of connecting it to teh ca, so when the voltage exceeds a certain point, it just switches full throttle on, and stops doing that as soon as it falls below that point. just one of those things i haven't gotten round to yet.

atm i just use the thumb throttle to do the startup throttle, rather than a button...but a button would work perfectly fine fo my situation.

 

[Sacker]

Throttle received! I bought the JST plug too and make the soldering (first time for me). I tested it and...

[youtube]cw3paN3vb64[/youtube]

So far so good let's see if I have time tomorrow to the final battle: solder it to the controller! wish me luck : P

 

[Sacker]

well guys... INSTALLATION SUCCESS!!!!! YESSSSSS : D : D : D

Not an easy path. First problem was that there's no space in the holes for the connectors in the bike chassis, the JST and the other plug from the throttle won't pass in the tiny space available so I had to leave them outside the bike and pass just the cables

On the other hand, I thought that I would need to solder two cables at least to the PCB, signal and +5V. But, I took a look at the Dupont connector that the PCB already had (and I have no idea of what it is for) and saw a red cable, and a black cable... multimeter there and voilà! a wonderful +5V line : )

Only one cable to solder then. First time soldering in a PCB. Fear OVER 9000. Here we go and... it didn't go that bad

When smoke came out while soldering I thought "that's it, bye bye controller". But was not the case haha

First testing:

Final result:

I'm very happy right now! Thank you very much amberwolf, TommyCat for show me the way to go and everyone that read and helped

 

[CesarGreat]

Hello, I'm new in this forum, sorry my English

I want to to similar work in my little btwin tilt 500

Works fine your adaptions?

I see 5 pin conector without use and I thinj that I must solder wires in this connector.

But I unterstand that in 5 pins conector, red and black wires are 5v, and the signal wire must be solder into the controller box?

I hope you can help me.
Thanks

 

[Sacker]

Hi Cesar (Italian?),

Works fine your adaptions?

to the date it works perfect, with 0 breakdowns. I enjoy it a lot : D

I see 5 pin conector without use and I thinj that I must solder wires in this connector.

Could you post a photo of that connector? Connector from where, the controller? What thumb throttle do you have, if you already bought one?

 

[CesarGreat]

I'm Spanish

My bike is same that your bike

I attach your photo with 5 pin contector, you sold wires in red and black wires



And the throtle that I want to install is



Without display

 

[Sacker]

bienvenido al foro paisano ; )

"But I unterstand that in 5 pins conector, red and black wires are 5v, and the signal wire must be solder into the controller box?"

correct, I didn't found the signal we require in any external cable, so I had to solder the wire directly in the PCB. For the 5V any source is valid so I took these ones that are already "outside", so it's the simplest way to go : )