[dommeij]

Great, thanks a lot for your help!

BTW if your dial is marked linearly that behaviour is abnormal. It means that something is still coded wrong. This is program is very simple and it changes calibration values in instrument cluster directly without any modification, as is. So if it works incorrectly, then it means that you misunderstood something in how it works.

As as solution, try to calculate step points relying on displaying speed points, not real speed points. I did the same job long time ago and couldn't remember which points I was using.

I've got an 1er M Series cluster. In this cluster the 120km/h is in the "middle". So I tooked about the half of max steps for 120km/h (3445 steps). For the 300km/h I entered the max steps (6890).

Between 0 and 120km/h the dial is marked lineary. So I took the 3445 steps and divided by 120. Then I got 28,7083 steps per km/h. That got me the steps for 10km/h (28,7083*10 = 287) and for 50km/h (28,7083*50=1435).

I corrected it like that:

Effective (real) speed (km/h): 0.0 / 7.5 / 46.8 / 115.6 / 295.2
Displaying speed (km/h): 0.0 / 10.0 / 50.0 / 120.0 / 300.0
Motor steps: 0 / 287 / 1435 / 3445 / 6890


In my eyes the steps should be right now. As I said, during driving the car, the needle shows the right speed. If I try the "test-drive" e.g. for 300km/h the needle stops exactly on 300km/h. But for 50km/h the needle stops at 40km/h...