Using a JN controller without a display interface?

[Chalo]

Hi all,

I ordered a few 26 amp JN three-mode controllers (UART #2) before I realized they require a display interface. But I would prefer to use them without the display.

JN 36V/48V E-bike Sine Wave 26A 500/750W SM Three-Mode-Brushless Controller | eBay

Fit for 24V500W,24V750W,36V500W,36V750W,48V500W,48V750W Brushless Motor. Suit For Electric scooter,ebike. Model:Three mode. Material: Aluminum + Plastic. Maximum current: 26±1A. Brake input: low level.

www.ebay.com

JN 36V/48V E-bike Sine Wave 26A,500/750W,SM,Three-Mode Brushless Controller | eBay

Fit for 24V500W,24V750W,36V500W,36V750W,48V500W,48V750W Brushless Motor. Suit For Electric scooter,ebike. Model:Three mode. Material: Aluminum + Plastic. Maximum current: 26±1A. Brake input: low level.

www.ebay.com

My question is, can I employ jumper wires like with a KT controller to run them without a display? If so, which pins do I need to connect?

I wish it were easier to find equipment that doesn't try to entertain you by doing things you didn't want or need.

Thanks.

 

[E-HP]

These are displays that work with JN controllers

• DC MOTO CONTROLLERBYLITHIUMBATTERY/JN SW900, S700, S800, S830, S866, S886, S890, S900, GD06, OMT-M3

Looking at the SW900 as an example, the blue conductor is for electric door lock, so it seems that putting bat+ to blue will turn it on.
Looks like the versions using waterproof connectors use a different color coding.

 

[amberwolf]

just keep in mind that without the display to command them otherwise, they're probably going to operate only in the default powerup mode. as long as that turns out to be the way you want them to operate, that's not an issue...but:

i've run into one controller myself that normally uses a display which by shorting the keyswitch and batt+ wires will power on...but it doesn't respond to any user input because (even with the display) it starts in a "mode zero" that doesn't do anything via throttle or pas. i guess it's supposed to be a safety feature, so you cant turn the bike on and accidentally just zoom away because you pushed on the pedal or twist the throttle grip accidentally while walking it after turnging it on or while you're climbing on; it only operates after you use the up-button to pick a non-zero assist mode.

pretty sure there's at least one thread around here about another controller that does that too, i think there was some discussion about using a small mcu to "sniff" the data sent for the assist level button pushes, and record it, then play it back at powerup automaticlaly so no display or user input would be needed to set it to max assist, but i don't recall if it ever went past discussion, etc.

 

[fechter]

You might need to get at least one display to see what it does by default. You could also trace out the power wires using it.

 

[Chalo]

You might need to get at least one display to see what it does by default.

I was thinking that, so I don't get caught unawares in some nerfed default mode. Still, buying something I'd pay not to have is a bummer.

You could also trace out the power wires using it.

I don't think I could do that, or at least muster up the gumption to try doing that. Arbitrary stupid bullshit-artist tech is the opposite of what I do.

 

[aae34]

I don't think I could do that, or at least muster up the gumption to try doing that. Arbitrary stupid bullshit-artist tech is the opposite of what I do.

What? Can't break up/open crap you didn't even want to buy? Or you don't have a multimeter?

 

[Chalo]

What? Can't break up/open crap you didn't even want to buy? Or you don't have a multimeter?

I can find the voltage. That doesn't tell me what it's doing there, nor what any of the 0V wires are for. The plug diagram is helpful, though.

 

[fill]

try-test the short, but use some ultra thin magnet wire that will burn and melt if any damaging current is passed? i would suggest fuse wire or lamp bulb filament but thats just my age..

 

[fechter]

The controller ad states: *The controller only fit for UART No.2 protocol controller, whatever that means.





If your connector looks like this one, I'd try connecting the red line to the blue line. No idea which number = which color.

I didn't see any kind of connection diagram for the controller. Did it come with one? These things tend to be very non-standard and every model seems to be different, so some kind of diagram is needed.

 

[E-HP]

Is this the second controller?

https://www.amazon.com/BEISGUANGS-Controller-Throttle-Suitable-Conversion/dp/B0D11GTZ8L

The kit uses an S866 display and pin 2 is the key lock.

https://manuals.plus/wp-content/sideloads/lcd-s866--instruments-v1-0-operating-manual-optimized.pdf

 

[Chalo]

Follow-up report on my issue:

On one of my holiday days off, I decided to swap an effective but noisy 22 amp KT controller on a bike of mine that I suspect has weak Hall sensors in its salvaged Jump bike motor. I choose to use one of these 26A JN controllers. When I bench tested it, I started with E-HP's first suggestion.

Looking at the SW900 as an example, the blue conductor is for electric door lock, so it seems that putting bat+ to blue will turn it on.

That did the trick nicely. I plugged everything in using a breakout cable for the Higo motor plug, and it fired up strong and smooth without my ever having to resort to the self-learn function.

I wired in a cheap handlebar mounted switch as a jumper from +5V to the blue terminal. The bike ran slightly stronger than before, pulling an indicated 27 amps maximum on my power meter. Top speed feels about the same, though I no longer have a display to track speed, and I haven't bothered to check it with a GPS speedometer.

The biggest improvement I notice and appreciate is that the motor sound is consistent now, where before the sound would change randomly when I released and reapplied the throttle. That was the behavior that made me think the Hall sensors were fishy.

Anyway, I'm very happy with the results and my bike is satisfyingly simpler and easier to troubleshoot now. Having only an on/off switch and a throttle makes it feel more like a normal bike to me than if it had PAS, settable assist levels, and a speedometer.