Brainpower gets incorrect speedsignal

Hello!

I have replaced controller and display on a first gen IKEA Folklig, the one with in-frame Protanium battery.

Problem is: As soon as the motor starts assisting, speed shows 99.9kmh.

I have tried tapping white to red wire and white to black wire in both 3-pin connector and in 6-pin hall connector. Display still reads ZERO!

With speedsensor disconected from controller I get:

Red is +5v

White is 0v

Black is 0v

Controller: XLD Brainpower 866C-6

Display: S866

Front wheel is a 36v, 250w with 6 pin connector. Only wheelspeed sensor, no motor hall sensors.

No throttle fitted

Everything works except speedo/speed limiter.

Probably it'sme that set the controller up wrong. I have a girlfriend, being wrong is a normal feeling

Settings are as follows. This is from the manual, something could be translated wrong.

P1 002 Brightness

P2 000 Km, we use metric in Sweden

P3 036 System voltage

P4 010 Time, automatic power off

P5 005 Numer of powerlevels

P6 27.5 Wheel diameter

P7 003 Number of magnets (there is 3) and also tried 1 with no sucess

P8 25 Speed limit

P9 000 Zero start (think this is correct with PAS only)

P10 000 Drive mode (PAS only, no throttle)

P11 010 Sensitivity of PAS (Guess this is personal preference more than right or wrong?)

P12 005 Help start intensity (not shure if it's correct)

P13 012 number of PAS magnets (disc with 12 magnets installed)

P14 014 Current limit

P14 29.0 Under voltage protection

P16 10km Odometer

P17 000 No enabling cruising (guess this is correct)

P18 100 Display speed ratio adjustment

P19 000 Powerbit (not a clue about this one)

P20 000 2 Protocol (not a clue)

P21 000 The throttle has a number of even proportional gear speeds (not a clue)

P22 000 No E-ABS (guess some kind of regeneration is disabled)

P23 000 When the trottle is reset it automatically enters brake state and locks the motor

First, you connect the speed sensor, red to red, black to black and white to white. That's if you have an external speed sensor. Why did you connect red to white and black? You set the number of magnets to one because there would be one magnet that you screwed to a spoke unless you're weird.

If you're using the speed sensor in the motor, you just connect the white wire to the white in the speed sensor connector or motor connector, then you set the number of magnets to 6. If the speed only shows a few mph, you change the number of magnets to one. I've never seen or heard of a motor that had three. What makes you think yours has three?

I beiieve your P07 is off. This is the number of magnets in the motor x gearing. It's a common setting in many LCD's. Most motors are between 80-100 for this value. Try 90 and if you see a reasonable speed, adjust P07 til the displayed speed matches actual. Most magbet couns are 16-20 and gearing is around 5:1, so that's why 80-100 is common. A high geared motor like a !100H is over 12:1, and the number is over 200.

The controller is able to spin the motor without knowing the number of magnets or gearing, so this number is only used by the LCD to display speed when the motor is spinning,

WHen the motor is coasting, then the display will use the speed sensor, plus the wheel diameter to calculate speed, Now it needs to know the numbe of times the soeed signal flashes in one revolution. WIth most bafang motors, this is six. Other moto5s and external speed sensors use one. This is a different P setting,

It is a mystery to me why they do it this way, but i have owned controllers w/o speed sensors that only give you the speed when the motor is turning. This might be OK for gearless motors,

My only possible thought now is that the controller runs in some kind "dumb mode" when there is no motor hall sensors connected and not sending a correct speed signal when motor assisting.

If I connect the wheel speed sensor to the motor hall connector I get a nice 5.0V/0.0V reading when spinning the wheel.

If I connect only Red and Black to the wheel sensor and leave the white wire disconnected I get 4.7V/0.0V reading.

If I connect all 3 wires to the wheel speed sensor connector I get 2.6V/0.0V.

Signal wires in the motor hall connector is 5V when not connected.

Signal wire in wheelspeed connector is 0V when not connected.

The motor PCB has a built in pull-up resistor and some caps. Could this be the problem/is it a good idea to desolder the resistor?

Seneagle:

I maybe was unclear. The sensor have been connected as it's supposed to be. Red to red, black to black and white to white in the 3-pin connector. I have tried to have it wired to the red/white/black in the 6 pin connector as well.

To rule out a bad sensor I tapped the wires together approx 2 times per second but still nothing on the display.

The speedsensor is built into the hubmotor. Looks like someone done some fixing before me. I replaced bearings and noticed there was different number of magnets. I have two identical bikes and there is no difference if I switch to the wheel with one magnet.

Harrys:

Still 99.9 as soon the motor starts to spinn or I roll the bike backwards. No difference between P07 set to 1, 90, 110 or 200.

The motor has 20 magnets and it takes 5.5 motor turns to complete one full whrel revolution.

I suppose 110 would be correct.

If the coasting sensor has a different P-setting. What number would that be?

Edited December 23, 20241 yr by Hampus A