what do I have to setup on "Trq Scale" and "PAS Poles"?
I have that Sempu BB too, though a square taper version, and I set the following parameters to the CA v3.1b20.
The PAS poles count on the BB indeed is 32. I even confirmed that with the help of the CA PAS diag. The CA max. setting for that is 24 though. But the 24 poles setting work OK, only the Pedal RPM display is not quite the correct. But it doesn't bother me at all.
BTW, when I bought the CA the original FW version on the unit did accept a 32 poles setting. And it did work just the same as the 24 poles setting on a never firmware.
Then the CA Zero torque Offset is that 1.5V listed in the specs. Max voltage the BB outputs is around 3V.
I set the Torque Assist Averaging to a value 16 poles. Which seem to work quite well too, it will affect the PAS assist startup delay, and this seem to be quite OK setting.
Then the Trque scale i.e. the Torque the BB outputs is a more difficult question. My experiments by measuring it with a known weight on the pedal resulted with two quite different values by two measurements with a different weights and one measured with the weight on top the pedal and the other with a weight hanging on a pedal axle between the pdal an d crank.
So cannot say what is the rel correct value but something like 38Nm/V is quite close I believe and works OK for me.
The BB has a separate wire for the PAS direction signal, but nevertheless on the CA you have to select PAS Signal type as 1-Wire signal. Otherwise the PAS doesn't engage at all. The BB will output 5V when pedaling forward and 0V when pedaling backwards.
And in order to get the PAS assist startup delay minimum I set the Sart RPM threshold to 5 RPM and Stop RPM Threshold to 18 RPM. And assist Start Power as -22HW.
It is really sensitive though and will engage even when the cranks rotate by themselves without actually pedaling.
A good idea maybe is also set The throttle Input Mode to Power and then control the output power with a DigiAux buttons or a potentiometer.
I have a Digiaux with the number of levels set to 8 levels.
Assist power factor I use is 1.00W/HW.
But actually the BB doesn't work very well in detecting the human power, as the max. torque it will measure is so low that you achieve that by merely resting the feet on the pedals.
The max torque it measures is 58Nm/V.
But actually if you set the crank alignment a little bit offset what is recommended (90 degrees), you must pedal a little bit harder to get the max. voltage out.
I found that when I accidentally bought a taper square cranks which had a different angle on the axle hole. The shimanos 45 degrees hole direction is correct. then you get the correct crank alignment.
And I tested it with my old bike Shimano nexus cranks the first. Thats why I discovered the very low max torque value the BB measures.
Some guys in the German pedelec forum had reviewed the BB too, and I think they judged the quality of the BB quite low. Lets see how it lasts, so far it has been working fine.
BTW. there is a new torque sensor from Bafang coming too: http://www.szbaf.com/en/components/comp ... 132st.html
It has 32 poles as well.