Practicalities of running a KT controller without an LCD

uPET

10 mW
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May 28, 2021
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I'd like to run my controller without having to rely on having an LCD screen connected all the time. Most of the time I have no need for it and can get the info I need from the separate ODO and voltmeter I have. I own several e-bikes and it's also getting expensive to keep buying these LCDs. Even from China an LCD-3 is around £30 each, so it soon adds up if you have to run several bikes. I've also incidents where I came off and the screen got totally smashed up, or the cables got damaged. I'd like to have one LCD-3 to set up and then run without it.

I have seen that KT controllers can be operated without a screen by connecting red to blue and yellow to black on the LCD connector to the controller. I haven't tried this yet as I was wondering about the basic practicalities of this: is it a permanent connection, or just momentary? Can a button (momentary or latching?) be connected instead of a jumper? Do both need to be switched at the same time? I was thinking of maybe a keylock to activate the controller.

I normally leave my bike in max PAS level, so an LCD is not needed...but on my scooter it would be good to be able to engage cruise control, to save having to press on the throttle constantly. I'm sure somebody must have configured an Arduino to have basic coms with the controller for this sort of thing? It would be good to have a cheap Arduino nano and a tiny display for basic info in a 3D printed enclosure...
 
Each time I buy an KT controller, I receive an additional contact that I can connect to the controller if I don't want to have an LCD.
I haven't tried it myself, but it should work if you look at this page:
Pswpower

Kt1.JPG

KT2.JPG
KT3.JPG
 
If it were my bike, I would connect the key switch between the red and blue leads. Since the red wire will have the pack voltage, it makes sense, to me, to have that voltage cut from the bike when not in use. I would keep the black and yellow wires shorted.

I like to set my LVC as high as I can to avoid having the battery manage that. Really, after 46v, and with voltage sag (42v), there is noticeable power loss. 46v is where I charge the bike. I notice that the battery gets warmer as the lower voltages are reached.

An Arduino would be a nice, clean, way to have some type of controller management. You may be able to hide it in the frame and connect via bluetooth. I've come across a few threads that showcase how the Arduino is used. It's a bit over my head, at this point, though.
 
I posted this in the General Forum, but didn't get much of a response:

I'd like to run my controller without having to rely on having an LCD screen connected all the time. Most of the time I have no need for it and can get the info I need from the separate ODO and voltmeter I have. I own several e-bikes and it's also getting expensive to keep buying these LCDs. Even from China an LCD-3 is around £30 each, so it soon adds up if you have to run several bikes. I've also incidents where I came off and the screen got totally smashed up, or the cables got damaged. I'd like to have one LCD-3 to set up and then run without it.

I have seen that KT controllers can be operated without a screen by connecting red to blue and yellow to black on the LCD connector to the controller. I haven't tried this yet as I was wondering about the basic practicalities of this: is it a permanent connection, or just momentary? Can a button (momentary or latching?) be connected instead of a jumper? Do both need to be switched at the same time? I was thinking of maybe a keylock to activate the controller.

I normally leave my bike in max PAS level, so an LCD is not needed...but on my scooter it would be good to be able to engage cruise control, to save having to press on the throttle constantly. I'm sure somebody must have configured an Arduino to have basic coms with the controller for this sort of thing? It would be good to have a cheap Arduino nano and a tiny display for basic info in a 3D printed enclosure instead of using up so much space with an LCD3 and having the expense of it.
 
If I had to guess? Red is +5V. Put your switch on that jumper and the thing will go dead when the switch is open. But that's only my guess, and I'd verify my suspicions with a multimeter before relying on it.
 
You might find that cruise control is implemented in the open source kunteng firmware such that it is activated by holding the throttle steady for a set period, in which case you could retain the feature despite ditching the display and buttons. Worth a look.
 
Just for fun today, I jumpered one of my KT controller ebikes amd rode around. I would guess that the default PAS level is probably between level 2 and level 3 (out of 5).. Couldn't really tell how fast it was going w/o the speed on the LCD. Throttle seemed to work as it alway did,

I would guess that you can ride around forever with the jumper set. If the default PAS level is strong enough for you, then you're set. But I would rather have my display.
 
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I have the Ktlcd3, which sometimes feels a bit too big, so I switch to a much smaller one called Ktlcd4.

By the way, in the picture I sent before , I would cut the blue wire in half and add a push button. When pressed, it sends a command to turn on the controller. Similarly, you can turn off the controller or let it run, and it will automatically turn off after a certain time If the bicycle is not in use.

IMG_9274.PNG
 
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