DIY Bafang CAN setup - HELP!

[brilleaux]

Hi,

I've been trying to put together a hub motor setup based around this controller...
Bafang CR A101
I'm also using the following Bafang components...
DP E160 display
SR PA121 bottom bracket sensor
The motor is not Bafang it's a Aikema 100SX (250w 36v)
The battery is generic

The problems I'm having:
-Turning the pedals does not operate the motor at all.
-If I put the bike into walk assist, the motor will operate properly for about 2 seconds before I get an error 21 message (speed sensor error)

I have bought a cheap multiboard Canable and hooked it up with Bafang Canable Pro...
-The sensor data shows the correct cadence readings, but nothing for torque
-If I do a speed sensor calibration the motor revs up for about two seconds before I get an error 21 and it shuts off.
-I tried fiddling with a few of the motor settings, didn't change any behaviour.

Any help much appreciated - I'm afraid I'm in way over my head!

 

[stancecoke]

I only have experience with this controller and a UART bottom bracket torquesensor (round 6pin Higo connector). But I found the same strange behaviour. The assist behaviour with the original Bafang firmware with a non-Bafang motor is completely unpredictable.

but nothing for torque

Sure. Your link shows a cadence sensor, not a torque sensor.
What connector is on the controller for the BB sensor? The round UART, or the roof shaped CAN?

 

[brilleaux]

Thanks Stancecoke!

Sure. Your link shows a cadence sensor, not a torque sensor.

Well that solves the mystery of the torque readings! I somehow got the idea that my bottom bracket had a torque sensor! Yes, my controller has a six pin round Julet style connector for the sensor. Would it matter if I just used a cadence sensor?

So do you think using a Bafang motor (need a front hub, so the H400?) would fix my problems? Is there other firmware I could try?

Cheers!

 

[stancecoke]

Would it matter if I just used a cadence sensor?

Yes, if the firmware expects a torque signal, a simple cadence sensor will not make the motor engage. There is an open source firmware for this hub motor controller, but it works with a torquesensor only also. Simple PAS mode is not implemented (yet).

BAFANG M215 (BBS01 CAN bus), M315 (BBS02 CAN bus), M510, M560, M820, CR-A101 FOC Open Source EBiCS Firmware for GD32F303 processors

This project supports several BAFANG Middrive- and Hubmotor systems meanwhile. You can find a Wiki on the GitHub repo. The latest releases can be found on github also, while the newest development files (maybe less than beta state) can be found in this thread. In the last weeks I've ported the...

endless-sphere.com

 

[brilleaux]

Fantastic, many thanks, your work on the firmware looks very cool!

I might have to shelve this project until I have my hands on a UART bottom bracket with a torque sensor. (I keep an eye out to see if firmware gets a cadence only mode update!)